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Copyright of Archives of Civil Engineering (Polish Academy of Sciences) is the property of Polish Academy of Sciences 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.)

An introduction to the journal is presented in which the editor discusses various articles published within the issue including one on fatigue of bars and tendons, one on gusset plates, and one on plane stability of shallow parabolic arches subjected to a central concentrated load.

This paper investigated the analytical solution of the bond strength between ribbed steel bar and engineered cementitious composites (ECC). In this method, ECC cover was regarded as a thick‐walled cylinder subjected to the uniform internal pressure which consisted of an elastic uncracked outer ring and a partially cracked inner ring. For the uncracked outer ring, it can be solved by the elastic mechanics theory. To solve the partially cracked inner ring, two key problems that had to be investigated were the crack width and the tensile stress–crack width relationship of ECC. According to the steady‐state cracking mode, the hoop deformation of ECC was expressed by the equal distribution and then the crack width can be determined. Besides, the fictitious crack model in fracture mechanic was introduced to describe the crack propagation process. Then a trilinear model was applied to reflect the tensile stress–crack width relationship of ECC materials, which considered the combined action of aggregate bridging and fiber bridging on the crack surface. Finally, the comparison between the calculation results and experimental results was carried out to prove the validity of the analytic method of bond strength proposed in this paper. Results indicated that the analytical solution and the experimental data fitted in well with each other. Then parameter analyses were conducted based on the analytical method proposed in this paper. [ABSTRACT FROM AUTHOR]

Investigation on the behaviour of hybrid beams is presented. Hybrid beam stands for an element with hybrid cross sections. This means sections that consist of steel and concrete parts, connected together with composite dowels, and both are considered for shear flow analysis. In practice, a more general solution may be used for bridges in the form of a beam in which the span sections are hybrid and the support sections are concrete. For the first time in the world, it was decided to introduce a girder in bridge construction, in which a concrete web with a thickness of only 20 cm was formed, directly connected to the steel web, so that a hybrid cross-section is created in accordance with the new European design regulations currently being developed (1994-1-102). The solution is new itself and requires also a new approach for internal forces determination. In this paper a parametric analysis of different hybrid beams with span range from 20 to 40 m and with different reinforcment ratio is performed to get knowledge on the influence of (1) concrete cracking and (2) rheology of concrete on the redistribution of internal forces. Results are analysed and conclusions are presented. As a final step, a general method for computer aided modelling of hybrid beams (hybrid beam concept) is proposed, which is based on the uncracked analysis. Such an analysis is designer-friendly and while appropriate benchmarked (as in this paper) can spare a lot of time needed for detailed iterative cracked analysis. [ABSTRACT FROM AUTHOR]

This paper deals with an approximate solution of Saint-Venant torsion problem of orthotropic bar with solid cross section. The boundary collocation is used to get the approximate analytical solution of the torsion problem. Examples illustrate the applications of the presented numerical solution. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including spatial variability modeling, numerical simulation and box girders.

A fault tolerant control method has been proposed based on the steer-by-wire system with dual steering actuator motors as presented in this paper. The paper built a real-time fault diagnosis mechanism based on the motor model and adaptive fading Kalman filter firstly. Then the diagnosis results were used to judge whether the angle feedback control and the torque feedback control need to be amended to realize fault tolerant control. Finally, hardware-in-the-loop test bench of this steer-by-wire system has been built for experiments and the results demonstrated that the fault tolerant control method was feasible and accurate. [ABSTRACT FROM AUTHOR]

The unrestrained torsional analysis of bars is an important theme in elasticity theory, first solved by Saint-Venant using semi-inverse methods. It has been considered and solved by several others using analytical methods and numerical procedures due to the importance in the design of machine parts under torsional moments. In this paper, the Saint Venant torsion problem is solved for rectangular prismatic bars using Galerkin-Kantorovich variational method (GKVM). The work presents a detailed theoretical framework of the problem, deriving using first principles considerations the stress compatibility equation in terms of the Prandtl stress function ϕ(x, y). The derived domain equation which is required to be satisfied over the rectangular cross-sectional domain is a partial differential equation of the Poisson type. GKVM is adopted as the solution method for finding the solution to the domain equation. The unknown Prandtl stress function ϕ(x, y) is assumed, following Kantorovich method to be a product of an unknown function for f(x) sought to minimize the Galerkin-Kantorovich variational functional (integral) (GKVF) and a known function (y2 - n2) which satisfies the boundary conditions at all boundary points in the y-direction, that is, at y = ±b. The resulting GKVF is a simplified functional whose integral is a second order inhomogeneous ordinary differential equation (ODE) in f(x). The integrand is solved to find f(x) leading in a full determination of the Prandtl stress function. The expression for stresses, torsional moments and torsional parameters are then found and they satisfy the boundary conditions and the domain equation. The results for the torsional moments and torsional parameters are identical to previous results obtained using double finite sine transform method (DFSTM), and analytical methods. The merit of GKVM is that it has led to the exact solution of the unrestrained torsion problems. [ABSTRACT FROM AUTHOR]

While the effects of axial compression on beams have long been known, the effect of tensile axial loads on one-sided transversely cracked beams is less known. The crack namely shifts the position of the resultant of the axial normal stresses deeper into the uncracked part of the cross-section, and the crack tends to open, causing a transverse displacement. Therefore, this paper focuses on empirical modeling of the considered phenomenon for slender prismatic beams in order to establish a suitable 1D computational model based on detailed 3D FE mesh results. This goal can be achieved through the already established simplified model, where the crack is represented by an internal hinge endowed with a rotational spring. Several analyses of various beams differing in geometry, crack locations, and boundary conditions were executed by implementing 3D FE meshes to establish the appropriate model's bending governing differential equation. After that, the corresponding parameter definitions were calibrated from the database of 3D FE models. By redefining the model's input parameters, a suitable solution is achieved, offering a good balance between the results' accuracy and the required computational effort. The functionality of the newly obtained solutions was verified through some comparative case studies that supplement the derivations. [ABSTRACT FROM AUTHOR]

This paper studies the chatter stability of composite cutter bar milling system in rotating coordinate frame. The main contribution of this paper is establishing a continuous distributed chatter analysis model for a composite cutter bar milling system in rotating coordinate frame. The stability of the milling system with a rotary symmetric dynamic cutter bar is predicted using the semi‐discrete time domain method. The effects such as internal damping, external damping, and symmetrical and asymmetric laminates on the stability of the milling system were analysed, and the results were compared between rotating and fixed coordinate frames. The results are consistent for symmetrical cutter bars in both the rotating and fixed coordinate frames. A new chatter instability zone appears at high rotating speeds due to the material internal damping of the rotating composite cutter bar. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the transient response of Lorentz force at finite magnetic Reynolds numbers Rm on an electrically conducting rectangular bar that is strongly accelerated in the presence of a localized magnetic field. This is done through numerical simulations utilizing a coupled finite-difference boundary element approach. The results show good qualitative agreement with existing experiments with a circular cylinder. The Lorentz force rise time is seen to be a linear function of Rm . The linear dependence of Lorentz force on Rm is found to be valid only for low values of Rm , after which the slope decays leading to an apparent saturation in the Lorentz force at sufficiently large values of Rm . Our results provide important information for the development of Lorentz force flow meters for transient flow applications. [ABSTRACT FROM PUBLISHER]

In this paper, a new possibility of fabricating a metal lattice structure with a continuous rod is demonstrated. A multi-layer, periodic, and aperiodic lattice structure can be manufactured with a continuous thin rod by bending it with a repetitive pattern. However, joining their nodes are challenging and an important problem to solve. This paper is investigating the joining of nodes in a loose lattice structure by delivering materials through the dipping process. Both liquid state (epoxy) and solid-state (inorganic particles) joining agents are considered for polymer–metal and metal–metal bonding, respectively. Liquid Carrier Systems (LCS) are designed considering their rheological behavior. We found 40% solid loading with the liquid carrier system provides sufficient solid particles transfer at dipping and join the lattice node using transient liquid phase bonding (TLP). 3D metal lattice structures are constructed, and their mechanical properties are investigated. The lattice structure shows comparable strength even with smaller relative density (< 10%). The strength and elastic modulus of all the fabricated samples decreases with the increase in cell size, which is consistent with the traditional wisdom. [ABSTRACT FROM AUTHOR]

In steel-concrete composite girders, composite dowel rib shear connectors can be used to transfer shear forces between the concrete slab and the steel section. In regions with negative bending moment, where concrete cracking occurs, the shear capacity of composite dowel connectors may be affected by transverse concrete cracks. So far, the internal shear-carrying mechanisms of composite dowel connectors in cracked concrete are not clarified, and existing shear capacity models do not account for concrete cracking. Hence, the present paper summarizes the results of 38 shear tests, providing novel insights regarding the pryout failure in cracked concrete. The tests were performed in an innovative test setup allowing the investigation of the impact of crack spacing and crack width. Using the test results, the present paper analyzes the phenomenology of pryout failure in cracked concrete. [ABSTRACT FROM AUTHOR]

Thin sheets assembled into three dimensional folding origami can have various applications from reconfigurable architectural structures to metamaterials with tunable properties. Simulating the elastic stiffness and estimating deformed shapes of these systems is important for conceptualizing and designing practical engineering structures. In this paper, we improve, verify, and test a simplified bar and hinge model that can simulate essential behaviors of origami. The model simulates three distinct behaviors: stretching and shearing of thin sheet panels; bending of the initially flat panels; and bending along prescribed fold lines. The model is simple and efficient, yet it can provide realistic representation of stiffness characteristics and deformed shapes of origami structures. The simplicity of this model makes it well suited for the origami engineering community, and its efficiency makes it suitable for design problems such as optimization and parameterization of geometric origami variations. [ABSTRACT FROM AUTHOR]

This paper presents a 2-D static analytical method in the frequency domain for the calculation of magnetic field distribution, eddy-currents, circuit model parameters, and steady-state performances in multiphase/multipole cage rotor induction motors with integer and fractional stator winding. The complex model allows to study the healthy, defective, and broken bars conditions in these electrical machines. The proposed static analytical model considers stator and rotor slotting with tooth-tips. The method is based on the resolution of Poisson’s, Laplace’s, and Helmholtz’s equations in stator slots, air-gap, and rotor bars regions, respectively. The electromagnetic torque is obtained from both the electrical equivalent circuit and Maxwell stress tensor that is given by the magnetic field calculation. The analytical results are validated by those issued from time harmonic finite-element method. [ABSTRACT FROM PUBLISHER]

This paper presents two types of new deployable mechanisms based on the motion characteristics of the four-bar slider–crank mechanism (FBSCM): the prism mechanism with constant cross-section and the round deployable mechanism. A new basic planar deployable unit based on the path-generating characteristics of the FBSCM is proposed. The method of building a deployable mast unit with one DOF from the new planar deployable mechanism is given. The prism mechanism with constant cross-section of one DOF is constructed, and the magnification ratio is analyzed. Moreover, the deployable unit with a negative Poisson's ratio for building the round deployable mechanism based on the properties of functional output of the FBSCM is proposed. The structure of the round deployable mechanism is described, and the parameter model with multilevel deployment is calculated and validated with cases given; the DOF of the round deployable mechanism is one. Last, the static analysis of the round deployable mechanism is studied by simulation; by locking 6 guide rails, the structure is found to have a balanced bearing capacity, and the bearing performance is improved compared with locking only one guide rail. [ABSTRACT FROM AUTHOR]

It is necessary to generate the yield position away from the column face to minimize damage to the beam-column joint during a large earthquake in a reinforced concrete building. The same efficacy can be realized using partially high strengthened rebar. The number of longitudinal bars can be calculated for a bending moment smaller than the column face, reducing their number compared to the conventional bar-arrangement method. This paper describes reinforced concrete an interior beamcolumn subassemblage tests using this rebar as the longitudinal bars of beams and a column. The beam yield hinge was formed at a position apart from the column face, and the damage to the beam-column joint was less than the conventional bar-arrangement method. Additionally, the good performance was obtained if the bending strength of the column was large, even if the shear capacity margin of the beam-column joint was small. The column-beam flexural strength ratio and shear capacity margin at the beam-column joint need to be set with consideration of their relationship. [ABSTRACT FROM AUTHOR]

The compression load of straight bars, for which the cross-sections are smaller compared to their length, causes a phenomenon of bending along the longitudinal axis. Upon reaching a certain level, called the critical level of the stresses, the bending deformations begin to increase beyond the bearing limit of the bar. It yields instantly, due to an unstable elastic deformation state, although the material's resistance limit has not been exceeded. The irreversibility of the phenomenon is dangerous especially for the railway tracks and is not fully mastered by calculation methods. They can eventually establish the level of the critical demand, which has values specific to each rail configuration. It is accepted that for loads lower than this level, buckling of the respective rail does not occur. The longitudinal tension in the railway tracks occurs due to the expansion caused by their heating under the action of the sun's rays, but also due to the friction between the rails and the train wheels. This paper proposes the realization of a study model of the buckling of the railway tracks. This model is represented by an assembly, built in the SOLIDWORKS application for which a Buckling simulation was made. The imposition of two distinct temperatures on the rails and crossties is the source of the model's request. The increase in the temperature of the component parts of the assembly causes their expansion, so implicitly the appearance of some longitudinal deforming forces, specific to the buckling phenomenon. [ABSTRACT FROM AUTHOR]

The planar mechanisms with articulated bars and gears (which we will simply note MeBaRd) are part of the general planar mechanics category. Although structural structural studies have been carried out [7], the structural synthesis of bars and wheels can be approached as a distinct problem. Some papers refer directly to a certain class of mechanisms, such as planetary mechanisms [1], [2], others stop on subsystems with zero mobility, called structural groups with toothed elements [6], [8]. In this paper, developing some ideas presented in [3], [5], a general algorithm for unitary structural synthesis of MeBaRd was developed and developed, having the input parameters: M - the degree of mobility and N - the number of contours. [ABSTRACT FROM AUTHOR]

Copyright of Technical Transactions / Czasopismo Techniczne is the property of Sciendo 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.)

Cites several research on bridge engineering. “Statistical lifetime predictions for aramid fibres,” by K. Alwis and C.J. Burgoyne; “Control of corrosion-induced damage in RC beams using CFRP laminates,” by M. Badawi and K. Soudki; “Reevaluation of deflection prediction for concrete beams reinforced with steel and FRP bars,” by P.H. Bischoff.

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would eliminate the need to permanently destroy machine components such as stator windings or rotor bars when acquiring data from a faulty machine for fault diagnostic purposes. Experimental results under healthy and various faulty conditions are presented in this paper, including issues associated with rotor bar-end ring contact resistances that showed the drawbacks of this motor in so far as emulation of rotor bar breakages. However, emulation of stator-turn fault scenarios was successfully accomplished. [ABSTRACT FROM AUTHOR]

This paper treats an exact elastica solution for a clamped-hinged beam, and its applications to a carbon nanotube. Although the elastica has a long history, and the exact post-buckling solution for the Euler buckling problem has been known for at least 150 years, it seems that the elastica solution for a post-buckled clamped-hinged beam has never been obtained. Therefore, the exact solution obtained in this paper constitutes an addition to the existing family of elastica solutions. As an application of the results, a post-buckling analysis of a single wall carbon nanotube is studied. Also, a potential use of the post-buckling analysis of the carbon nanotube for the determination of its Young's modulus has been indicated. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a flexural analysis of I-shaped laminated composite beams. A general analytical model applicable to thin-walled I-section composite beams subjected to vertical load is developed. This model is based on the shear-deformable beam theory, and accounts for the flexural response of the thin-walled composites for arbitrary laminate stacking sequence configuration, i.e. unsymmetric as well as symmetric. Governing equations are derived from the principle of the stationary value of total potential energy. Numerical results are obtained for thin-walled composites under vertical loading, addressing the effects of fiber angle and span-to-height ratio of the composite beam. [Copyright &y& Elsevier]

This paper deals with the modelling of a plastic beam experiencing softening. This kind of behaviour is observed in steel or reinforced concrete structural members undergoing large rotation amplitudes, which may occur typically for civil engineering structures in the seismic area. The homogeneous cantilever beam loaded by a concentrated force at its extremity is considered. This simple structural problem with gradient bending moment allows an analytical treatment of the evolution problem. It is shown that a local plastic softening model makes the evolution problem ill-posed. Moreover, if we require the plastic curvature to be a continuous variable of the spatial coordinate, Wood’s paradox is encountered. A non-local gradient plastic model is developed in order to overcome this paradox. However classical gradient plastic models may not eliminate the ill-posedness since the beam response may not be continuous with respect to the loading parameter. The new gradient plastic model, presented in this paper, is similar to previous classical gradient models. The main difference is the yield moment considered as a non-local material parameter. This permits to ensure continuity between the elastic and the plastic regions during the loading process. These solutions are controlled by the ratio between the material length and the geometrical length of the beam. The new evolution problem may remain ill-posed as it possesses a finite number of solutions (which can be unique). Closed-form solutions of the unknown deflection are given. [ABSTRACT FROM AUTHOR]

This paper is concerned with the analysis of curved sandwich beams with a focus on debonding and buckling/wrinkling of the faces. An elasticity-theory based approach is used for studying through-thickness tension in curved sandwich beam in the first section. The approach ensures an accurate description of the through-thickness stresses in curved sandwich beam. In the second section, the critical load for instability of a curved beam on an elastic foundation which is correspondent to the skin of sandwich beam, is considered and compared with the result for a flat beam on an elastic foundation. The flexural strength of sandwich beam is then studied with a view to identify debonding and local instability characteristics. The effects of various parameters, such as geometrical configuration, stiffness of the skin and core, on through-thickness tension stress and local instability respectively are also studied. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Sciences is the property of Faculty of Engineering - Assiut University 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.)

Introduces series of articles published in the November 2004 issue of the "Journal of Bridge Engineering." Methods involved in determining the dynamic impact factors for horizontally curved composite single and multicell box girder bridges; Presentation of the results of several studies that provides comparisons between experimental and analytical results and the V-load method; Description of the applications of laser-based instrumentation for highway bridges.

The objective of this paper is to use µ-X-ray fluorescence (XRF) analysis to evaluate the fineness and components of European Medieval Silver Bars samples. Conductivity measurements were used to assess the fineness and localization of the faults found in the samples. Because unevenness causes a change in conductivity, the tests were performed on the flattest areas of the Bars. Some rods, such as B3 and B9, have greater conductivity than others. All bars were subjected to the segregation test. In the instance of certain bars, it was not always practicable to categorically state that segregation had happened. There is no diminishing conductivity curve as one moves away from the zero height, as there is for bars B1, B8, and B9. As a result, there may be no solidification on these bars from Obverse to Reverse. A scanning electron microscope was used to record the following bars at various positions on the bars, and quantitative determinations were achieved using energy-dispersed XRF analysis through intensity measurements of the element-specific wavelength. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to study the wave propagation in a generalized piezothermoelastic rotating bar of circular cross-section using three-dimensional linear theory of elasticity. Design/methodology/approach – A mathematical model is developed to study the wave propagation in a generalized piezothermelastic rotating bar of circular cross-section by using Lord-Shulman (LS) and Green-Lindsay (GL) theory of thermoelasticity. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been derived by using the thermally insulated/isothermal and electrically shorted/charge free boundary conditions prevailing at the surface of the circular cross-sectional bar. The roots of the frequency equation are obtained by using the secant method, applicable for complex roots. Findings – In order to include the time requirement for the acceleration of the heat flow and the coupling between the temperature and strain fields, the analytical terms have been derived for the non-classical thermo-elastic theories, LS and GL theory. The computed physical quantities such as thermo-mechanical coupling, electro-mechanical coupling, frequency shift, specific loss and frequency have been presented in the form of dispersion curves. From the graphical patterns of the structure, the effect of thermal relaxation times and the rotational speed as well as the anisotropy of the of the material on the various considered wave characteristics is more significant and dominant in the flexural modes of vibration. The effect of such physical quantities provides the foundation for the construction of temperature sensors, acoustic sensor and rotating gyroscope. Originality/value – In this paper, the influence of thermal relaxation times and rotational speed on the wave number with thermo-mechanical coupling, electro-mechanical coupling, frequency shift, specific loss and frequency has been observed and are presented as dispersion curves. The effect of thermal relaxation time and rotational speed on wave number for the case of generalized piezothermoelastic material of circular cross-section was never reported in the literature. These results are new and original. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Polytechnic Institute of Iasi - Construction & Architecture Section is the property of Sciendo 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.)

The phenomenon of the lateral instability of the vehicle when the steering is one of the extremely serious and dangerous problems. To improve safety and stability, vehicles often are equipped with stabilizer bars at the front and rear axles. However, the passive stabilizer bar cannot guarantee safe and stable performance in dangerous cases. Therefore, the active stabilizer bar is used to replace the passive stabilizer bar. The active stabilizer can automatically generate an anti-roll moment depending on the condition of the vehicle at each time. In dangerous cases, the anti-roll moment of the active stabilizer bar is much greater than the passive stabilizer bar. This research focused on the problem of establishing a spatial dynamics model in combination with a nonlinear double-track dynamic model to describe the state of oscillation of the vehicle when steering. The PID control method is used to control the hydraulic stabilizer bar. The results of the research indicated that when the vehicle was equipped with the hydraulic stabilizer bar, the values of the roll angle, the displacement of the un-sprung mass, the vertical force at the wheel, ... were significantly reduced. [ABSTRACT FROM AUTHOR]

Purpose – RC columns are very susceptible to fire, as besides the detrimental effects due to this action, second-order effects play a significant role. In this work, the aim is to consider the ISO834 standard fire, and the focus is put on checking the proper use of a simplified method suggested on Annex B.3 of EC2 to account for the second-order effects in RC columns. Design/methodology/approach – The use of Annex B.3 of EC2 is obscure in what concerns the peak strain to be considered at the most deformed cross-section concrete fibres, and this affects the evaluation of the second-order moment installed in the RC column during the fire. Two hypotheses are analysed in the paper, and validated against the calculations from the advanced code SAFIR: the one where the classical limit of 3.5‰ is assumed for the peak concrete strain in compression, and a more refined compatibility of the section total strains. Findings – The simulations demonstrate that using the simplified method with hypothesis H1 leads to unsafe conclusions. Conversely, hypothesis H2 compares much better with SAFIR predictions, and it can be rather easily adopted in real applications. Originality/value – The indications provided here for the proper application of the simplified method are very useful for practical use. They overcome an unclear aspect on its implementation, not yet previously addressed. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum: Architectura is the property of Wydawnictwo SGGW 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.)

This paper presents cyclic responses of five exterior beam-column joints made with 100 ksi (690 MPa) longitudinal bars, 115 ksi (790 MPa) transverse reinforcement, and 10 ksi (70 MPa) concrete. The test joints satisfied the existing ACI 318 design provisions for special moment frames, except for the joint shear demands, the anchorage limitations of the maximum bar yield strength, the maximum concrete strength, and the minimum clear spacing between headed bars. The test results show that the minimum development length can be used for anchorage of closely spaced headed bars in well-confined joints. It is found that the deformation capacity of beam-column joints could be increased by reducing the joint shear demand or increasing the joint transverse reinforcement ratio. The presented test results were assembled with previous research data for assessing the design provisions. This paper proposes several modifications to the existing design provisions for beam-column joints using high-strength reinforcement and concrete. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study on the anchorage strength of conventional and high-strength steel hooked bars. Three hundred and thirty-seven exterior beam-column joint specimens were tested with compressive strengths ranging from 4300 to 16,500 psi (30 to 114 MPa). Parameters investigated included the number of hooked bars per specimen, bar diameter, side cover, amount of confining reinforcement, hooked bar spacing, hook bend angle, hook placement, and embedment length. Bar stresses at failure ranged from 22,800 to 144,100 psi (157 and 994 MPa). The majority of the hooked bars failed by a combination of front and side failure, with front failure being the dominant failure mode. Test results show that development lengths of hooked bars calculated based on ACI 318-14 are very conservative for No. 5 (No. 16) bars and become progressively less conservative with increasing bar size and concrete compressive strength. [ABSTRACT FROM AUTHOR]

Current guidelines do not cover the subject of the fiber-reinforced polymer (FRP) reinforced concrete (RC) members subjected to simultaneous flexural and axial loads. The obvious implication is that, presently, RC columns cannot be designed with FRP longitudinal bars and ties. This paper suggests the consideration of this type of application of glass FRP (GFRP) reinforcement for the next revision of guidelines by (1) showing the theoretical approach at the basis of the behavior of GFRP-RC members subject to simultaneous flexural and axial loads; (2) providing revised design and analysis provisions for GFRP-RC columns similar to those in practice for steel-RC columns; (3) showing how interaction diagrams can be developed for both rectangular and circular cross sections; (4) explaining the rationale for a new formulation of the strength reduction factor for simultaneous flexural and axial resistance that is consistent with current guidelines, and; (5) reformulating the shear strength computation. Recognizing the limited availability of experimental data on GFRP-RC column behavior, the design provisions proposed in this paper are not applicable to structures in seismic zones and may be applicable only to buildings of limited size and height. An example of the design of a GFRP-RC square column for a hospital facility concludes the paper. [ABSTRACT FROM AUTHOR]

Detection and evaluation of corrosion in reinforcing steel bars (rebars) commonly used in cement-based structures is an important ongoing concern. Embedded sensor technologies hold promise for this purpose. In recent years, modulated scatterer technique (MST) has shown great potential as an embedded sensor technology. The first step in evaluating the potential of embedded MST for rebar corrosion detection is to evaluate its potential for detecting the presence of subtle corrosion in a rebar. This short paper investigates the measurement potential for a dual-loaded differential MST approach for detecting relatively subtle corrosion in a steel rebar. [ABSTRACT FROM AUTHOR]

In 1974 W. S. Hemp constructed a prototype structure to carry a uniformly distributed load between two pinned supports. Although Hemp's structure had a significantly lower volume than a parabolic arch with vertical hangers, it was shown to fail the Michell optimality criteria, and therefore to be non-optimal. In this paper we demonstrate that if limiting compressive and tensile stresses are unequal then Hemp's structure is optimal for the half-plane provided the ratio of limiting tensile to compressive stresses falls below a certain threshold. An analytical proof is presented and the finding is confirmed by results from large scale numerical layout optimization simulations. [ABSTRACT FROM AUTHOR]

In induction machines, motor current signature analysis has been tested in many industrial cases with good results. However, this method does not always achieve successfully results to detect broken-rotor-bar under variable load torque. Recent advances on signal processing techniques have provided more powerful tools for faults diagnosis. This paper proposes a novel approach based on Power Spectrum Density estimation (PSD) to diagnose and detect broken-rotor-bar faults in induction motor under different levels of load. This paper also analyses three different spectral decomposition methods applied to induction machine stator current, namely Welch, Burg and Multiple Signal Classification (MUSIC). Based on different power spectral estimation concepts, the frequency resolution, variance and detection capability are different from each other according to the set of parameters used. The proposed methodology aims to determine which spectral estimate method best suited for implementation in an automated system for fault detection. Also, the PSD estimate is used for feature extraction and aims at identifying the descriptors that show high variability between different classes and thus would help distinguishing between them. Various scenarios are examined using data sets of stator current signals from experiments under different load, and the results are compared to obtain the best performance for automated process. [ABSTRACT FROM AUTHOR]

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The problem of impact of a thermoelastic rod against a heated rigid barrier is considered, in so doing lateral surfaces and free end of the rod are heat insulated, and free heat exchange between the rod and the rigid obstacle or ideal thermal contact occurs within contacting end. The rod's thermoelastic behavior is described by the Green-Naghdi theory of thermoelasticity. D'Alembert's method, which is based on the analytical solution of equations of the hyperbolic type describing the dynamic behavior of the thermoelastic rod, is used as the method of solution. This solution involves four arbitrary functions which are determined from the initial and boundary conditions and are piecewise constant functions. The procedure developed enables one to analyze the influence of thermoelastic parameters on the values to be found and to investigate numerically the longitudinal coordinate dependence of the desired functions at each fixed instant of the time beginning from the moment of the rod's collision with the barrier up to the moment of its rebound both without account for the stress and temperature fields coupling (in the companion paper, Part I) and in the case of coupling thermoelasticity (in this paper). As a numerical example, the impact of a thermoelastic rod against a heated barrier is considered with a small parameter of coupling between the strain and temperature fields. It has been shown that the presence of small coupling results in the generation of a new shock wave of small amplitude, namely: the reflected thermal wave from the incident elastic wave at the free rod's end. The rod's rebound may occur either at the moment of simultaneous arrival at the contact place of two reflected waves: elastic wave from the incident thermal wave and thermal wave from the incident elastic wave—or at the time when the reflected elastic wave from the incident elastic wave reaches the contact point. [ABSTRACT FROM AUTHOR]

On the evening of December 27, 2005, the fascia beam supporting the east-side parapet wall of the third span of the Lake View Drive Bridge failed under the action of dead load. This paper describes the structural testing and posttest forensic examination of two girders recovered from the partially collapsed Lake View Drive Bridge. The objective of this paper is to describe the tests conducted and report the observations. An interior and an exterior prestressed concrete adjacent box girder were tested to failure in flexure. Prior to testing, an extensive visual inspection was conducted to assess the extant condition of the 42-year-old girders. Following testing, the girders were sawcut near their failure regions to permit an extensive forensic investigation. Conclusions based on the pre- and posttest inspections and test results are presented. Recommendations intended to reinforce issues that need to be considered in the bridge inspection and rating process of similar structures are presented. [ABSTRACT FROM AUTHOR]

In this paper, a power assisted system for an overhead crane is presented. This system is realized by measuring the swing angle of a crane and moving the trolley and girder in the desired direction. Therefore, operators can move a heavy object freely using only slight force. In this paper, two kinds of controllers are proposed. One is a PD controller that emulates the dynamics of object with damping and it moves the object in proportional velocity to the operating force in steady-state. Another is a PID controller that maintains the velocity of object continuously after operators cease the application of their force. Its dynamics, damping characteristics, steady-state and admissible condition of controller gain are discussed in regard to the respective controllers. This system is applied to an experimental overhead crane in the laboratory, and the effect of energy saved by the power assist is shown by measuring the heart rate of operator. [ABSTRACT FROM AUTHOR]