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A cross‐laminated timber rib panel is a floor system comprising cross‐laminated timber plates rigidly bonded to glued‐laminated timber 'rib' beams. A design method was developed to estimate the fire resistance of cross‐laminated timber rib panels, based on a bending load‐carrying model. The bending load‐carrying model calculates the bending load‐carrying capacity of cross‐laminated timber rib panels based on simulated temperature distributions of numerical models. The numerical models were validated against the experimental results of full‐scale fire resistance tests. The proposed design method is based on the overall approach of the current revised draft of EN 1995‐1‐2:2004, that is, prEN 1995‐1‐2:2023, and provides conservative estimates of the bending load‐carrying capacity. The effective width is one of the most important design parameters and its influence was studied in detail. A limit value of 60% of the effective width according to prEN 1995‐1‐1:2023 is proposed as effective width in fire. [ABSTRACT FROM AUTHOR]

This paper is focused on a new structural type - sandwich shell, which includes inner and outer shells connected by hoop connectors to achieve composite action; and a functional layer in the middle. Considering that the hoop connectors are not completely rigid, there will be limited slip between the inner and outer shells, which will lead to partial Degree of Composite Action (DCA). Due to the existence of the hoop connectors and shear lag effect, the stress distribution along the width direction of the shell is uneven, which can be described by effective width. Considering all these factors, this paper first develops an analytical model for sandwich shells with different configurations of connectors; and uses finite element analysis results to verify the analytical model. Next, a parametric study is conducted using the analytical model to study the effects of material strength, the ratio of the thickness of the functional layer to the thickness of the single layer shell, and the ratio of the arc length to the width of the sandwich shell on the effective width. It is found that DCA can significantly affect the stress and strain distributions of the sandwich shell. The effective width for 100% DCA can be used as a conservative value to represent those of other DCAs. Finally, a simplified calculation formula, which can be used in practical design, is derived based on the effective width for 100% DCA. [ABSTRACT FROM AUTHOR]

In the frame of a research project, the structural behaviour in fire of cross-laminated timber rib panels were studied based on numerical investigations. The floor system consists of cross-laminated timber plates rigidly bonded to glued-laminated timber ribs. The numerical investigations comprised uncoupled thermo-mechanical simulations of two types of finite element models, a beam system and a flexible-in-shear multi-layered part, to investigate the influence of the effective width in fire. All models were validated against the experimental results of previously tested full-scale fire resistance tests. A parametric study analysed the composite cross‐sections' effective width in fire for a parameter range expected in practice and gave proposals depending on the thickness of the CLT layers. For the conservative case of thin CLT layers, a limit value of 60% of the effective width at normal temperature is proposed as effective width in fire. [ABSTRACT FROM AUTHOR]

Due to the shear strain in the plane of the slab, the parts of the slab remote from the steel beam lag behind the part of the slab located in its proximity. This shear lag effect causes a non-uniform stress distribution across the width of the slab. As a result, several standards have introduced the concept of an effective flange width to simplify the analysis of stress distribution across the width of composite beams. Both the computed ultimate moment and serviceability limit states are directly impacted by the effective width. The effect of using a large number of contact points as shear connectors on the effective width of a steel beam flange has not been investigated. A three-dimensional finite element analysis is carried out in this paper. The ABAQUS software (version 6.14) is used for this purpose, where several variables are considered, including the surface area connecting the steel beam and concrete slab, the transverse space, and the number of shear connectors. It was discovered that the number of shear connectors on the steel beam flange has a major impact on the effective width. The many connectors work together to provide a shear surface that improves the effective width by lowering the value of the shear lag.

A new method for evaluating the effective flange width of simply supported rectangular box-girders in bending is illustrated. It aims to overcome the lack in the literature of a general method able to supply the effective flange width for a general distribution of loads along the beam axis, not restricted, i.e., to the few cases reported in standard codes. The method consists of finding an analytical expression for the effective width under sinusoidal loads of arbitrary wavelength and combining the results in the framework of a Fourier analysis. The model allows investigating the shear-lag effects on displacements and stresses. The analytical formulation proposed is validated against numerical results supplied by refined Finite Element analyses. [ABSTRACT FROM AUTHOR]

Due to the shear strain in the plane of the slab, the parts of the slab remote from the steel beam lag behind the part of the slab located in its proximity. This shear lag effect causes a non-uniform stress distribution across the width of the slab. As a result, several standards have introduced the concept of an effective flange width to simplify the analysis of stress distribution across the width of composite beams. Both the computed ultimate moment and serviceability limit states are directly impacted by the effective width. The effect of using a large number of contact points as shear connectors on the effective width of a steel beam flange has not been investigated. A three-dimensional finite element analysis is carried out in this paper. The ABAQUS software (version 6.14) is used for this purpose, where several variables are considered, including the surface area connecting the steel beam and concrete slab, the transverse space, and the number of shear connectors. It was discovered that the number of shear connectors on the steel beam flange has a major impact on the effective width. The many connectors work together to provide a shear surface that improves the effective width by lowering the value of the shear lag. [ABSTRACT FROM AUTHOR]

The existing research primarily focuses on wood-concrete composite beams, with limited studies on the bending performance and effective width of wood-concrete composite slabs. A full-scale composite slab with screw connections was constructed and subjected to static load testing. The study extensively investigated the ultimate bearing capacity, load-deflection curves, interface slips, strain distributions of cross-section and effective width of the wood-concrete composite slab. It was found that the failure mechanism of the composite slab involved both bending and tensile failure of the wood beams. As the applied load intensified, a marked augmentation in the longitudinal strain of the concrete slab was observed; along the width direction, the longitudinal strain of concrete slab manifested a curved distribution. The precise determination of the effective width of the concrete slab within the composite floor could be accurately achieved via the utilization of a simplified computational approach. In order to simplify the analysis, the M-shaped section of composite slab was approximated as T-section composite beams when evaluating the bending behavior. The linear-elastic model was shown to be accurate in predicting the bending stiffness and load-carrying capacity of composite slabs.

To investigate the shear lag effect of railway continuous channel girder bridge, taking the Damuxi Bridge on the Hengfeng- Fuzhou Railway as an example, the shear lag effect was estimated under the various conditions by employing the finite element method. The range of effective widths for the structure was proposed, and the influence of different section forms for channel girders on the shear lag effect was also illustrated. The results show that the shear lag effect occurring at the centerline of the bridge in the longitudinal direction of the deck slab is becoming remarkable in the middle support section. The phenomenon of alternating positive and negative shear lag effects in the middle support section and the main span middle section of the deck slab, and the shear lag effect is more pronounced on the upper surface of the bottom slab than on the lower surface of the main span section along the cross-bridge under different conditions. Under constant + live load conditions, the positive shear hysteresis effect in the middle bearing section is observed at the edge of the top plate and at the centre line of the bottom plate, while the positive shear hysteresis effect in the mid-span section of the main span is observed at the centre line of the top plate and at the edge of the bottom plate. For the two kinds of condition acting on the deck slab, including dead load + live load and main force + additional force, the suggested values about the effective width ratio are 0. 83 and 0. 80 near the middle of the main span, both 1 near the side support, and 0. 74 and 0. 73 at the middle support, respectively. The shear lag effect is more significant occurring at the upper surface of the deck slab in the main span section than that on the lower surface for the different cross-sectional forms of channel girders. In addition, the shear lag effect is more significant compared to bridge deck plate due to the presence of web in the deck when the box shaped bridge decks are used for channel girder bridge. [ABSTRACT FROM AUTHOR]

Summary: The present study deals with introducing a novel approach toward estimating the effective width of flanged reinforced concrete shear walls (FRCSWs). Due to the paucity of studies in assessing the effective width of nonrectangular sections, this paper aims at proposing efficacious formulations for the effective width estimation of short, squat, and slender T‐ and U‐shaped reinforced concrete (RC) shear walls subjected to the simultaneous action of the axial and lateral loading. To this end, at first, FRCSWs are simulated in the flanged shear wall numerical laboratory (FlashLab) program, which utilizes the finite element Abaqus software to analyze the walls. Thereafter, employing the developed numerical models, an extensive parametric investigation is conducted for a wide range of the key parameters. General expressions have then been developed to estimate the effective width of flanged RC shear walls invoking the evolutionary polynomial regression (EPR) analysis in conjunction with the genetic algorithm (GA). To assess the capability of the established equations in predicting the effective width of flanged sections, R‐factors have been calculated for all the cases examined in this study, which ranged between 0.78 and 0.94. Furthermore, a comparison has been made among the results attained through the proposed methodology and those obtained using the conventional design codes. It was revealed that the relative error obtained employing the proposed formulations is less than that of the corresponding values of the design codes by approximately 30% on average. The superiority of the established framework stems from consideration of the following: (1) influential parameters, (2) effective width variations at different performance levels, (3) loading direction, and (4) type of the wall in the effective width calculation process. [ABSTRACT FROM AUTHOR]

The effective width is a relevant parameter for the design of bridge overhang slabs under concentrated loads. Experimental tests have been used to assess expressions for its calculation. However, the load capacity increases with the width until a transition area is reached. Test specimens may have lacked enough width to reach full shear capacity, affecting thus the evaluation of the results. On the other hand, within the transition area, a threshold value has been hypothesized to match the effective width. This paper aims to provide recommendations for minimal widths that guarantee the full capacity of overhang slabs and to assess the calculation of the effective width by means of the threshold value and other formulations. The effect of the edge beam is also considered. A campaign of validated non-linear FE-simulations based on experiments on range of width-span ratios was performed. The results suggest using a width-span ratio of at least 4.0 for slabs without an edge beam and 5.3 for slabs with an edge beam for the experimental practice. The efficiency of the formulation for the effective widths is diffuse and the use of threshold value leads to unsafe predictions. Instead, linear-elastic FE-analyses are recommended for the design practice.

Most international codes of practice didn't consider the flange contribution of reinforced concrete T-beams in shear strength. In inverted T-beams loaded on the web, if the flange area is considered in shear strength, the results may be overestimated because after the web cracks open, the aggregate interlock which has a more significant contribution to shear decreases, and shear stresses tend to concentrate at the compression zone, which is located in the web of inverted T-beams. To quantify flange contribution, an experimental program backed by a finite element program based on a nonlinear 3D finite element model was carried out. The experimental program investigates the shear response of beams with varying flange geometry and reinforcement. the results showed that by increasing the flange geometry, the shear strength rises but up to a certain point, the contribution of the flange reinforcement to shear must be neglected. In the current analysis, the greatest contribution of flanges was determined to be 44.5% of total shear resisted by control beam without flange. Furthermore, the numerical model was utilized to visualize and quantify characteristics that are difficult to get experimentally, such as shear stress distribution between the web and the flanges. Also, the model was used to solve a matrix of beams to obtain the maximum shear resistance to make an accurate simplified computational model which shows good agreement with the experimental and finite element results.

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Load testing of bridges is often used as a reliable method for assessing the capacity of in-service bridges with low analytical load rating factors. This paper presents a detailed load rating study of an 82-year-old concrete slab bridge with an unusually large aspect ratio of 3.73 by performing non-destructive diagnostic and proof load tests. The test-based modified rating factor is evaluated based on the American Association of State Highway and Transportation Officials (AASHTO) approach and the structural effective strip width approach which is then compared with the analytical rating factor from a simplified 1-D beam-line model. Field data is also used to evaluate the impact of the rotational stiffness of the bridge on its global response and load rating factor. The field test results based on the AASHTO approach reveal that the rating factor improves by up to 53% compared to the analytical rating factor. Monitoring the rotational residual response at the bridge supports is proven to be an effective method for assessing the global response of the bridge during field testing. The study shows that adding a rotational spring with a field-calibrated rotational stiffness to the 1-D analytical model of the bridge can significantly increase the load rating factor. [ABSTRACT FROM AUTHOR]

A new method for evaluating the effective flange width of simply supported rectangular box-girders in bending is illustrated. It aims to overcome the lack in the literature of a general method able to supply the effective flange width for a general distribution of loads along the beam axis, not restricted, i.e., to the few cases reported in standard codes. The method consists of finding an analytical expression for the effective width under sinusoidal loads of arbitrary wavelength and combining the results in the framework of a Fourier analysis. The model allows investigating the shear-lag effects on displacements and stresses. The analytical formulation proposed is validated against numerical results supplied by refined Finite Element analyses.

The bridge's span structure comprises a connected beam designed to support a concrete slab poured over parallel steel supports. Simultaneously, segmental construction, shrinkage, and the flow of concrete play a significant role in stress redistribution over time. The span construction is statically indeterminate due to its connections with the abutments, and temporal deformations occur under additional complex conditions. In this analysis, we employed a calculation model based on the layered finite elements method developed by the authors. This model can be utilized to analyse both statically indeterminate supports and the predicted phased construction method. It accounts for changes in the static system and loading, as well as variations in the layers within the coupled section and the viscous properties of the concrete over time. The calculation analysis results reveal that viscous concrete deformations, combined with different moments of activation of individual segments, have a significant impact on stress redistribution over time. Such intricate analyses are indispensable for ensuring the required safety and cost-effectiveness of the bridge span construction. [ABSTRACT FROM AUTHOR]

In order to study the effective width and flexural load capacity of the butterfly web box girder, a test model was designed and fabricated, and static loading tests were carried out. The ABAQUS finite element model was established and its force performance was analysed. The effective width was calculated based on the assumption of flat section, combined with the Chinese, American and Japanese codes, and the discount factor of the butterfly web was introduced to establish the ultimate flexural load capacity of the butterfly web box girder. The box girder ultimate flexural load capacity calculation formula. Through the load capacity calculation value and test value, finite element value for comparison, the results show that: the butterfly web and the top and bottom plate work together, the force performance is good. According to the Chinese and American norms to calculate the effective width of the butterfly web box girder is more reasonable. On the basis of the effective width, the calculation of the butterfly web box girder flexural load capacity and test value is more consistent, and the results are on the safe side. [ABSTRACT FROM AUTHOR]

Effective width (beff) has been widely used by designers, and several specifications can be selected. However, insufficient research has been conducted on the beff of single and twin I-beam composite girders. Thus, finite element (FE) models, calibrated by the experiment, were used to study the effects of slab thickness, web position, interaction degree (ID) of shear studs, width-to-span ratio, and their coupling effects on beff. Different loading types and two definitions of beff were elaborated. The FE results were compared with specifications in Eurocode 4 (EC4) and AASHTO LRFD bridge design specifications (AASHTO). The following results were obtained. The modeling agrees with the experiment. The critical steel height-to-slab thickness ratio is around 4. When the ratio deviates from the critical value, beff is reduced with the increase of slab thickness. ID has a slight influence on beff. beff changes within 10% when ID changes within 10%. The maximum beff can be obtained when the web spacing-to-physical width ratio is 1/2. The decrease of web spacing brings a maximum reduction of 14% on beff, whereas increasing web spacing results in a maximum reduction of 70% for twin I-beam. The coupled effect of web position and slab thickness is limited. The maximum difference is 25%. Recommended equations were proposed to evaluate beff for single I-beam and twin I-beam composite girders based on the specifications in EC4 and AASHTO, which can ensure that the negative error is within 10%. [ABSTRACT FROM AUTHOR]

Effective width is known as an important parameter in the analysis and design of non-rectangular Reinforced Concrete (RC) shear walls. Current design codes, i.e., ACI, CEN, UBC, and BS, propose a constant value for the effective width calculation of flanged sections, which proved to be conservative and ineffective in some cases. Of the conventional non-rectangular RC shear walls, the L-shaped sections have rarely been investigated in the technical literature. As the L-shaped RC shear walls can extensively be employed for structural and architectural reasons, a reliable assessment of the effective width of L-shaped sections is essential. Therefore, this paper attempts to propose applicable formulations for the effective width estimation of L-shaped RC shear walls. In that regard, a number of numerical investigations involving finite element analyses have been conducted in the ABAQUS software in order to evaluate the cyclic performance of L-shaped RC shear walls. The numerical results including the axial strain and displacement distributions have been attained for 42 L-shaped RC shear walls with three different aspect ratios, at which the shear-lag effects have been taken into consideration. In addition, on the basis of the evolutionary polynomial regression (EPR) analyses, applicable formulations have been established to be utilized for the initial estimation of the effective width of the L-shaped sections. The effectiveness of the proposed expressions has been examined by assessing the R-factor of the estimations. On account of the average R-factor of 0.88, the capability of the proposed expressions has been ascertained in assessing the effective width of L-shaped sections. Moreover, in order to further highlight the unavoidable effects of level of axial loading and drift values on the variation of the effective width, different curves have been presented. Furthermore, calculation of the Mean Absolute Relative Error (MARE) index demonstrates that uniform distribution can well estimate the effective width of L-shaped RC walls.

The generation of plastic waste is increasing all over the world at an alarming rate, therefore raising concerns related to its disposal. As space for landfilling is becoming scarce and as incinerating the plastic waste leads to the release of toxic elements into the environment, recycling becomes a viable and an attractive option in pursuit of sustainable development. This paper investigates the flexural behavior of mortar beams reinforced with recycled plastic mesh. To achieve this objective, 27 mortar beams were prepared, with 24 of them containing waste plastic mesh with different void ratios and effective widths. All beams were cured for 28 days and then tested using a three-point bending test. Mid-span deflection was measured for each increment of load to obtain the load deflection curve. Moreover, a numerical simulation was performed on all mortar specimens using finite element software ABAQUS and a comparison was made with the experimental analysis. Test results showed that the addition of plastic mesh increased the flexural toughness and ductility of mortar beams. Furthermore, it was noticed that as the effective width ratio increased from 0 to 0.58, the ultimate capacity and flexural toughness increased. Beyond this level, a decrease was observed. On the other hand, the ductility index was proportional to the flexural toughness for all mesh effective width ratios. Comparing the ultimate capacity, flexural toughness and ductility index between the experimental and numerical data, there was a difference of up to 7%. This indicates that the numerical output can be a good predictor of the performance of plastic inside the mortar. Hence, using recycled plastic mesh could be recommended for improving the flexural performance of mortar beams, creating a sustainable composite. [ABSTRACT FROM AUTHOR]

An experimental study with many variables was carried out to investigate the effective width of simply supported composite beams (T and L sec. beams) with and without slab opening. Three full-scale composite slab models with six different carrier simply supported composite beams (three with T-sec. and three with L-sec.) with constant slab rectangularity were tested.� Each model was loaded by a uniform distributed load (within elastic behavior zone) then loaded by means of two-concentrated loads system acting at equal distances from supports till failure. One of them without slab opening and the others with two symmetric slab openings and constant opening position in direction parallel to main supporting beams longitudinal axes. In this research, the tested model features, materials properties and measurement instrumentations are described in brief. The maximum load carrying capacity; crack patterns, deflections at different positions and generated strains in form of estimated effective width were experimentally investigated. Interesting gained results were recorded such that more than 100% of slab effective width is preserved for interior supporting beams if the openings are away enough from carried composite slabs structural carried zones while only 70% was preserved for exterior ones. Also, concentrated loads manner reduced carried composite slab effective width to be85%in average of that recorded for equivalent distributed loads. Some conclusions and recommendations are introduced.

The production of plastic material continues to increase around the world. Consequently, large amount of waste plastic is generated. This will lead to environmental concern due to its disposal. In order to reduce the environment effects and cost, waste plastic can be recycled and utilized in other applications including construction. This paper investigated the flexural behavior of non-structural concrete beams containing waste plastic meshes as a replacement of traditional steel reinforcement. To achieve this objective, beams with steel reinforcing bars and waste plastic sheets with different effective widths and patterns were prepared. After 28 days of curing, the beams were subjected to an increasing load until failure and the central deflection was measured at each load increment. Furthermore, a numerical analysis was performed on the specimens using ABAQUS software. This will allow the comparison between the experimental and numerical results. The experimental data indicated that using plastic sheets improved the flexural toughness and ductility of concrete beams. Additionally, correlations were carried out between the ultimate capacity of the beams, the flexural toughness and the effective width of the plastic meshes. As the effective mesh width increased, the flexural toughness and ultimate capacity of the concrete beams increased. The results of this investigation will allow greater utilization of waste plastic in construction activities. [ABSTRACT FROM AUTHOR]

This paper focuses on a particular application of birch plywood in adhesively bonded connections, namely, a node of a timber truss. The aim is to investigate the influence of the plywood's additional width and the load-to-face grain angles on its load-bearing capacity in tension (tensile capacity). The experimental tests started from the case with the plywood width the same as the glulam width. The reference tensile strengths tested from the specimens with a small gap between glulam elements are high at any load-to-face grain angle, i.e., around 51 MPa, 44 MPa, and 41 MPa at 0°, 22.5°, and 45° to the face grain respectively, due to the changed crack paths of the 22.5° and 45° plywood. The very low angle-dependent tensile strength is unique for cross-grained veneer-based panels in adhesively bonded connections, and is promising for applications in truss nodes. With the increase of the plywood width, the tensile capacity of birch plywood tended to reach a plateau. Test results indicated a low angle-dependence of the maximum tensile capacities of birch plywood but the plateaus were reached at different plywood widths. This phenomenon can be well interpreted by introducing the concept of effective widths and spreading angles. The specific spreading angles were determined by comparing the predicted tensile capacity to the test results, which should be valid for adhesively bonded birch plywood plates in truss nodes irrespective of the geometrical parameters. • The reference tensile strengths of birch plywood with a small gap between glulam elements show very low angle-dependence. • Tests with small and long gaps derive different reference tensile strengths at 22.5º and 45º due to the changed crack paths. • The maximum tensile capacities at 22.5º and 45º are only slightly lower than that at 0º. • The tensile capacities at different load-to-face grain angles reach plateaus at certain widths. • Spreading angle theories predict the tensile capacities in a satisfactory manner. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

District Heating is a cornerstone for the decarbonisation of the heating and cooling sector in Europe. Nonetheless, this technology is currently absent in a majority of the continent’s urban areas, and hence the need for appropriate methods by which to estimate the cost, as well as underlying cost parameters, to assess the feasibility of developing district heating networks is of general interest. One key underlying cost parameter, the concept of Effective Width, which is the ratio between a land area and the trench length within that land area, is the focus quantity of this work. Effective Width enables a first order assessment of the total route length of pipes in a given urban area and, together with the average diameter of the pipes, allows an estimation of the investment cost of installing district heating pipes. However, initial implementations of the Effective Width have been based on rather limited empirical evidence, such as a small set of cases and often disregarding service pipes due to lack of data. Another shortcoming of previous studies is the extrapolation of established relations into more sparsely populated areas. By assembly of a richer database, which contains building data, heat consumption data in the supplied areas, as well as actual network information (numerical and geographical), provided by several district heating companies in Denmark and Sweden, the objectives of this study are twofold: first, to improve the general understanding of Effective Width and its relation to building density, and secondly, to study the particular case of sparse areas. The results of this study provide new insight to enhance our understanding of the Effective Width concept which may facilitate better assessments of future district heating systems.

Cold-formed steel (CFS) structural members retain their preferred position in the lightweight construction industry, which is due to their significant advantages. The optimization of these CSF elements will make it possible to construct buildings at very competitive prices, having in addition an increased load capacity, and thus obtaining a stable and economical construction. The main objective of this research being the evaluation of the effectiveness of these new sections in (CSF) and the estimation of the remarkable instabilities as well as the failure modes. This article deals with an experimental study on the behavior of CSF beams of delta and bi-delta shape, solicited by four-point bending loads. These cross section shapes are often used in floors as main and secondary beams. The properties of this type of sections are most often based on the method involving the effective width designated by the Eurocode 3 standard. A nonlinear analysis by finite elements (FE) using the ABAQUS calculation program is carried out, thus making it possible to compare the experimental results with the numerical ones as well as those which are given by the theory proposed by Eurocode 3. Finally, the results obtained essentially showed that the failure modes of the delta and bi-delta beams corresponded to the buckling modes local. [ABSTRACT FROM AUTHOR]

An experimental study with many variables was carried out to investigate the effective width of simply supported composite beams (T and L sec. beams) with and without slab opening. Three full-scale composite slab models with six different carrier simply supported composite beams (three with T-sec. and three with L-sec.) with constant slab rectangularity were tested. Each model was loaded by a uniform distributed load (within elastic behavior zone) then loaded by means of two-concentrated loads system acting at equal distances from supports till failure. One of them without slab opening and the others with two symmetric slab openings and constant opening position in direction parallel to main supporting beams longitudinal axes. In this research, the tested model features, materials properties and measurement instrumentations are described in brief. The maximum load carrying capacity; crack patterns, deflections at different positions and generated strains in form of estimated effective width were experimentally investigated. Interesting gained results were recorded such that more than 100% of slab effective width is preserved for interior supporting beams if the openings are away enough from carried composite slabs structural carried zones while only 70% was preserved for exterior ones. Also, concentrated loads manner reduced carried composite slab effective width to be85%in average of that recorded for equivalent distributed loads. Some conclusions and recommendations are introduced. [ABSTRACT FROM AUTHOR]

Long and complex composite steel-concrete structures are becoming common, requiring a deep understanding of the effects induced by the simultaneous action of axial forces and bending. In fact, the axial force generated, for instance, by cable inclination in cable-supported structures can modify the stress distribution within the elements compared to bending scenarios, thereby necessitating a revision of the effective width to be utilized. Nonetheless, current design codes, including Eurocode specifications and others, lack provisions for addressing the combined effects of axial force and bending, as they are exclusively tailored for bending. This limitation can introduce design complexities, necessitating the implementation of intricate Finite Element (FE) models, which impose substantial computational loads and design efforts. The methodology proposed in this paper overcomes these challenges allowing to assess the stress distribution and resistance of composite deck at Serviceability Limit State (SLS) and Ultimate Limit States (ULS) by leveraging results obtained from standard beam models typically used by structural designers or practitioners. A comprehensive parametric analysis using nonlinear finite element models is performed to validate the developed methodology. A comparison with the Eurocode 4 formulations highlights that the proposed method provides superior accuracy in estimating peak stress in concrete slabs under combined compression and bending. Additionally, it facilitates straightforward verification at the ULS in compliance with Eurocode requirements. • Current codes ignore shear lag on axial forces in steel-concrete composite beams. • A simplified method is proposed for combined axial and bending effects. • A comprehensive parametric analysis is performed to validate the approach. • The method evaluates effective width at Serviceability and Ultimate Limit States. [ABSTRACT FROM AUTHOR]

Since the introduction of the effective width concept for the estimation of the linear heat density, it has been frequently used by researchers to calculate district heating distribution grid costs in pre-feasibility phases. Some researchers, however, still prefer using a detailed modelling approach to get reliable results. This paper aims to highlight the advantages, disadvantages, and challenges of using the effective width concept to calculate district heating distribution grid costs compared to a detailed, optimisation-based modelling approach such as DHMIN. The outcomes of this paper reveal that although there are differences in obtained indicators such as trench length or distribution gird costs, both approaches deliver very similar patterns in different areas with various heat demand densities and plot ratios. Furthermore, it was revealed that for getting reliable results for a given case study, the input parameters and cost components should always be tuned to that case study regardless of the approach used. [ABSTRACT FROM AUTHOR]

Since the introduction of the effective width concept for the estimation of the linear heat density, it has been frequently used by researchers to calculate district heating distribution grid costs in pre-feasibility phases. Some researchers however, still prefer using a detailed modelling approach to get reliable results. This paper aims at highlighting advantages, disadvantages and challenges of using effective width concept for calculation of district heating distribution grid costs in comparison to a detailed, optimisation-based modelling approach such as DHMIN. The outcomes of this paper reveal that although there are differences in obtained indicators such as trench length or distribution gird costs, both approaches deliver very similar patterns in different areas with various heat demand densities and plot ratios. Furthermore, it was revealed that for getting reliable results for a given case study, the input parameters and cost components should always be tuned to that case study regardless of the approach that is used.

Analytical theories related to the buckling criterion and strength of thin-walled structures are classified into flat plate and cylindrical shell theories and others (conical shell and spherical shell). To discuss the accurate predictions for the ultimate load-bearing capacities (ULBCs) of thin-walled steel (TWS) composite members under longitudinal compression and solve the long-standing problem of the different effective width (EW) definitions under different main TWS structural specifications, a simple model of a flat element supported in parallel by two cylindrical shell elements (corner ridgelines) on both longitudinal sides was analyzed. In addition, a simplified method to evaluate the reduction factor of the postbuckling ULBC caused by the initial imperfections was developed. The rational results for releasing additional anti-buckling functions of the ridgeline revealed herein are expected to be beneficial to the structural lightweight optimization for not only civil and construction engineering but also other broad areas such as spacecraft and aircraft engineering.

The Eurocode uses the Effective Width Method for the Cold Formed Steel design and this method is currently based on the semi‐empirical Winter formula. This formula is based on the von Karman's approach which considers that the ultimate load on a compressed thin plate with large deflections is reached when the critical stress of the plate effective width is equal with the yield stress. Winter modified the formula in order to match the experimental results but there are numerous cases in which the formula underestimates the strength capacity. Also, the formula has no input for the initial geometric imperfections. This paper presents a semi‐analytical alternative based on the trigonometric series representation of the displacement field. The procedure is applied to the uniform compressed rectangular plate with simply supported edges (internal plate of a thin‐walled member) and with one free longitudinal edge (outstand plate). This new approach considers the initial geometric imperfections with various shapes. [ABSTRACT FROM AUTHOR]

The objective of the research is a steel fiber‐reinforced concrete slab in compression in a composite frame joint. EN 1998‐1 relates only to composite joints with common concrete slab. This standard prescribes two mechanisms: mechanism 1 acts in the concrete slab with a concentrated compressive force on the column flange; mechanism 2 consists of struts and tie model, where concrete struts compress the concave parts of the column cross‐section. By these mechanisms, it is prescribed inaccurate formula for the effective width calculation of a common concrete slab in compression in the nodal zone, as the standard procedure does not consider the contribution of the confinement effect to the resistance of mechanism 1. Mechanism 1 represents a direct bearing of the concrete slab against the column flange. There is a concrete slab in compression confined by transverse reinforcement, slab continuity around the column flange and friction on the column flange. Moreover, some publications describe different inclination of the concrete struts of mechanism 2. The resistance of mechanism 2 significantly depends on this inclination. The aim of this work is to derive a more accurate formula for calculation the effective width of the steel fiber‐reinforced concrete slab in compression in the nodal zone. Experiment with real‐sized isolated composite joint, validation of ATENA numerical models and parametric study of composite joints with fiber‐reinforced concrete slab are the main steps of this research. [ABSTRACT FROM AUTHOR]

The production of plastic material continues to increase around the world. Consequently, large amount of waste plastic is generated. This will lead to environmental concern due to its disposal. In order to reduce the environment effects and cost, waste plastic can be recycled and utilized in other applications including construction. This paper investigated the flexural behavior of non-structural concrete beams containing waste plastic meshes as a replacement of traditional steel reinforcement. To achieve this objective, beams with steel reinforcing bars and waste plastic sheets with different effective widths and patterns were prepared. After 28 days of curing, the beams were subjected to an increasing load until failure and the central deflection was measured at each load increment. Furthermore, a numerical analysis was performed on the specimens using ABAQUS software. This will allow the comparison between the experimental and numerical results. The experimental data indicated that using plastic sheets improved the flexural toughness and ductility of concrete beams. Additionally, correlations were carried out between the ultimate capacity of the beams, the flexural toughness and the effective width of the plastic meshes. As the effective mesh width increased, the flexural toughness and ultimate capacity of the concrete beams increased. The results of this investigation will allow greater utilization of waste plastic in construction activities.

Intensification of coal mining from mine seams of 0.55–1.20 m thick requires increasing efficiency of loose coal loading that may be achieved by selecting the optimal parameters of auger operating device of a shearer. The most reliable way to determine effect of the auger parameters on the energy parameters of the shearer operation is experimental research in actual operating conditions. As the subjects of the research, we selected up-to-date UKD400 and UKD200-500 shearers, operating in representative conditions of the Krasny Partizan mine of SE SVERDLOVANTRATSIT and Ternovskaya mine of DTEK PAVLOGRADUGOL PJSC. An adaptive method for specific mining operating conditions is proposed for determining the specific energy consumption of the shearers on material disruption and loading for thin seams in actual operating conditions based on fixing the values of currents of the cutting drive motors. Based on processing of the experimental data, an indicative dependence of the power for rock mass loading on the feed rate and the effective width of the operating device is determined. Increasing the auger effective width results in increasing the loading power and specific energy consumption. At the same time, the higher the shearer feed rate, the greater the growth of the loading power and specific energy consumption. This is due to the beginning of the process of loose rock mass circulation, and the larger the auger effective width, the more intensive the circulation process, and at the lower feed rate of the shearer the process starts. A method is proposed for selecting the auger optimum effective width based on the criteria of minimum specific energy consumption and maximum commercial productivity.

The present paper aims to determine numerically in the Abaqus® software the parameters that have the greatest influence on the effective width of steel-concrete composite box girder bridges. In the technical standards and in the literature, there is no specific recommendation for calculating the effective width in steel-concrete composite box girder bridge. As an alternative, the existing recommendations for steel-concrete composite I-girders are adopted. Therefore, in the absence of standards recommendations for steel-concrete composite box girder bridges, there is a need for an investigation into the distribution of stresses at the steel-concrete interface, because if the effective width was admitted incorrectly, may result in costly or even unsafe solutions. For this purpose, the effective numerical width of 160 models of steel-concrete composite box girder bridges was determined, in which the study variables were the configuration of the transversal section, the slab height, the span length and the elements arrangement in the cross section. After analyzing the results, it was proposed a recommendation to determine effective width of steel-concrete composite box girder bridges. [ABSTRACT FROM AUTHOR]

The evaluation of the district heating network investment costs requires the knowledge of its topology. However, when assessing district heating potential, the topology is not known a priori and a simulation is required. One method for modelling future heat networks involves the use of Minimum Spanning Tree, from the graph theory. In this work, the MST is used together with real networks lengths to elaborate an updated equation describing the effective width in correlation with the number of building ratio instead of plot ratio. The reason motivating the use of simulated networks lies in the goal of analysing sparse areas where there's a general lack of data. In this study, the census cells vertexes and local roads layout are used as inputs for the application of the MST in order to simulate DH network layouts in areas where DH is not present. The method has been validated by running simulations in areas where DH is already present, allowing the comparison of the respective lengths. The validation shows a variable but systematic overestimation of the simulated lengths. The study of the error has brought to the definition of a correlation between accuracy of results and the share of buildings with centralized heating systems suitable for DH connection. The updated version of the effective width confirms the exponential tendency and gives higher results for Italian cities then for Scandinavian ones, showing an important impact of the city structure in the curve. The city of Milano is finally used as a case study to show the effects of using the updated effective width curve. [ABSTRACT FROM AUTHOR]

The strain-stress state (SSS) of a free flange of a constant width of the typical ship thin-walled beam with a break of an axis of I-section at elastic deformation is analyzed. The beam consists of a tapered part and prismatic parts of different heights, adjoining it. In the result of handling of data of SSS there was the methodology created for definition of an effective width and appropriate reduction factor for the dangerous cross section and along tapered part in the wide range of change of geometrical parameters. As investigations showed the behavior of a flange of an inclined/tapered part and in places of its break is complex for the reason of complex warping/deplanation and presence of stress concentrators, with the result that in a flange there is no plane stress state completely realized, necessary for calculation of an effective width after classic method. That's why for the determination of an effective width of a flange of an inclined part there was used projection of components of SSS into its plane, so that a (quasi-) plane stress state was achieved, suitable for the application of the classic methodology of calculation of an effective width. As a result, the effective width depends on five independent parameters: width and thickness of a flange; angle of inclination of a tapered part; fillet radius in the place of transition from little height of a web to a tapered part; relation of heights of little and larger webs. Determination of an effective width took place considering only shear lag, without taking into account of buckling of a flange and web; there is excluded the influence of flexure component caused by local bending of flange platting by the way of definition of components of SSS at its middle surface. Also there is presented the verification of the Suslov formula assigned for the dangerous cross section of the investigated beam in the narrow range of changeable geometric parameters. [ABSTRACT FROM AUTHOR]

ABSTRACT: Bridges are structures built to overcome obstacles and allow continuity of transport routes. In the search for efficient construction systems, steel-concrete composite structures, especially box girder bridges, emerged. The American AASHTO and European EN 1994-2-2 standards present design procedures for this type of bridge, but there are still doubts about which portion of the concrete slab contributes to each web strength in composite section (effective width). The present paper aims to evaluate, by numerical analysis in the Abaqus® software, the concrete slab effective width and to verify whether the expressions for its calculation in composite I-girder bridges are valid for box girder sections. After analyzing the results, it was found that the standards recommendations for composite I-girder cannot be applied directly to box girders. Finally, based on the numerical analysis, an equation was proposed to calculate the effective width of steel-concrete composite box girder bridges.

The aim of this paper is to quantify the evolution's effect of parallel electrical discharges on the performance of a plane insulation placed simultaneously under conditions of a non-uniform transversal distribution of pollution and positive DC voltage. The results emanating from this experimental study revealed a maximum increase about 18% of flashover voltage of insulation's non-uniform transversal distribution of the insulation compared to that obtained under uniform pollution distribution. The existence of a limit value of the electrical conductivities' ratio of the lightly and the heavily contaminated bands, characterized by an early development of the electrical flashover arc of the insulation in the heavily polluted band, was demonstrated in this investigation. Also, a direct link has been established between the flashover frequency of the insulation's highly contaminated band, under the effect of a non-uniform transversal distribution of pollution and its electrical resistance. Similarly, an approximation linking the insulation's length to the effective width of an electrical arc in its last phase of development and consequently the number of electrical arcs that can develop in the two differently polluted bands just before the insulation's flashover was done in this study. [ABSTRACT FROM AUTHOR]

Abstract Most of the engineering problems involving structural elements of steel-concrete composite beam type are approximations of the structural problem involving concrete plates connected by connectors to steel beams. Technical standards allow the replacement of the concrete plate element by a beam element by adopting a reduction in the width of the plate element known as effective width. The effective width is obtained, in most technical norms, taking into account only the parameters of beam span length and distance between adjacent beams. Numerical and experimental works found in the literature show that this effective width depends on several other parameters, such as the width and thickness of the concrete slab, and the type of loading. The objective of this work is to verify the influence of the partial interaction in the evaluation of the effective width of composite beams formed by a concrete slab connected to a steel beam with deformable connection, being used in numerical simulation three types of finite elements: a plate element for nonlinear analysis of the concrete slab; a bar element for non-linear analysis of beams with cross-section defined by a polygon; and an interface element which connects the plate and beam elements, simulating the deformation effect of the shear connectors. In the studied examples, it was found that the reduction of the shear connection stiffness at the interface between the concrete slab and the steel beam leads to a decrease in the shear lag effect and, consequently, makes the effective width of the concrete slab closer to the its real width. In another example, curves are constructed to define the effective width of a composite beam with medium stiffness. Considering maximum stresses and maximum displacements, these curves are obtained by forcing the equivalence of the approximate model with the model closest to the real problem.

The thin plane plates are largely used in practice as single elements or as components of the thin-walled structures, and their behavior under compression is characterized by large post-buckling load-carrying capacity. Various semi-analytical solutions of the uniformly compressed simply supported plate with large deflections were formulated almost a century ago, mainly solving the fundamental equations governing the deformation of thin plates, or using classic energy methods. Due to several shortcomings, none of these solutions were introduced in the design codes of thin-walled members. This paper presents new semi-analytical solutions based on classic energy methods. The main innovation is brought by the considered displacement field which is far more accurate than the ones used by the previous formulations. The initial geometric imperfections are considered, and the proposed solutions are validated against numerical solutions and experimental data. The validation is also supported by a publicly available software application. [ABSTRACT FROM AUTHOR]

A thin rectangular steel wall in a steel shear wall structure always simultaneously sustains the lateral load and the gravity load. The gravity load can affect the shear strength of a steel shear wall. However, this effect is not considered in most of the research and standards, which may lead to potential danger in practice. From the previous study of the authors, the shear strength reduction was not only influenced by the load magnitude but also by the vertical stress distribution. For a simply-supported thick square wall, i.e. width to thickness ratio smaller than 100, the stress distribution can be accurately described in a cosine form. However, for a thin wall under compression and in-plane bending, the cosine distribution will largely overestimate the vertical stress, especially when the walls enter the post-buckling condition. To narrow the knowledge gap, this paper proposed a vertical stress distribution in a three-segment form, i.e. in both edge-segments, a combination of linear and cosine functions from the edge stresses to the minimum stress, while in the middle segment, the stress distribution is constant and equal to the minimum stress. Two strategies, i.e. effective width method and Bedair's method, are chosen to determine the width of the edge portion. A finite element model (FEM) is developed to evaluate the proposed distribution. The FEM has been verified using the results of our own experiments and tests done by Zaraś et al. The results show that the proposed three-segment stress distribution can well describe the behavior of thin walls of different slendernesses and stress gradients. The cosine distribution obtained from theoretical solution and the effective width model by Bedair are also discussed. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the concrete filled thin-walled welded steel tubes. Square and rectangular columns are tested with and without the bond between the steel profile and concrete. In order to remove the bond in the latter columns a polyethylene (PE) film is placed inside of the steel profiles. Experimental results are verified via the finite element analysis and compared to the results obtained using the analytical calculation methods. The significance of the steel--concrete bond is evaluated, referring to the differences of the critical loads, ultimate loads and effective cross-sectional areas of the columns with and without the PE film inside and the differences are found to be considerable. It is found that the columns without the film had an up to 47 % higher effective cross-sectional area to full cross-sectional area ratio. The average reduction of the effective cross-sectional area of the column having a poor bond is found to be 12 %. It is also found that the resistance is often overestimated when using the analytical formulas, especially for the columns with the PE film inside. [ABSTRACT FROM AUTHOR]

Steel and concrete composite bridges and viaducts, especially in the box section, have several advantages. However, there is big discrepancy in the recommendations for calculating the effective width of the slab. For this reason, the influence of such variation on the design of compósite steel and concrete bridges and viaducts in a box section is studied. For that, 11 models were designed, varying the cross section and span, in which, considering the recommendations of the NBR 8800 (2008), AASHTO (2017), EN 1994-2-2 (2005) and those of the literature of Zhu et al. (2015) and Yuan et al. (2016), it was calculated the capacity resistant to the bending moment of the composite section and the limit distributed load for dimensioning in the Service Limit State. In the analysis, comparing the values of capacity resistant to the mean bending moment of NBR 8800 (2008) with AASHTO (2017), the first presents values 17.07% higher. In addition, NBR 8800 (2008) and EN 1994-2-2 (2005) allow shipments distributed to upper limits, on average, 14.51% and 13.18%, respectively, to those made possible by AASHTO (2017). Moreover, as the span of bridges and viaducts increases, the greater the overall variation in the resistance of the composite section. Therefore, the discrepancy between the normative recommendations has a significant influence on the design process, and it is important to carry out studies in this area in order to standardize the procedures to determine the effective width. [ABSTRACT FROM AUTHOR]