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Hole-flanging process is widely being used in metal forming industry. Using elastomeric punch instead of the rigid one may enhance the quality of surface finish of the produced part. The objective of this paper is to investigate the sheet metal hole-flanging process with soft punch. This investigation is carried out via numerical and experimental analysis using polyurethane rubber with hemispherical end as flexible tool. Material of workpiece is the aluminum AA 1050-H14. Numerical simulation of the flexible hole-flanging process is performed with Abaqus/ Explicit. A Mooney-Rivlin model is adopted to predict the hyperelastic parameters of rubber punch with Shore hardness 70 A. The Coulomb friction law is adopted to model the contact between soft punch/part and part/rigid die. An experimental set up is developed to produce flanges. Numerical result presents a comparison between classical hole-flanging process with rigid tool and flexible process with rubber tool in term of variation of thickness distribution along the flange wall. Using soft tool with hemispherical end may improve the formability of aluminum flanged part compared to conventional forming technique. Numerical prediction of thickness distribution is assessed with the experimental measurement along the wall of the flanged part for validation purpose.

The article considers the production of housing parts with variable wall thickness along the perimeter. The use of this type of products is possible for various areas of industrial development, as the most important branch of the national economy. Examples of the use of cylindrical body parts of variable thickness in the electrical industry are given. The technological process of manufacturing body parts with variable wall thickness along the perimeter of sheet blanks consists of the operation of drawing without thinning and the operation of drawing with thinning and end support, as well as direct extrusion. The simulation of the described operations is carried out, the process diagrams and the semi-finished product obtained as a result of forming a round sheet billet are shown. The power modes of the first and second operations of the technological process of manufacturing body parts with variable wall thickness along the perimeter from sheet blanks are studied. Recommendations are given for the manufacture of body parts with and without a flange. The technological process of manufacturing body parts with variable wall thickness along the perimeter from sheet blanks presented in the article ensures high quality of products while saving material and energy resources, and also leads to a reduction in labor costs.

The article deals with reliability calculation of a rigid node of a steel frame of a building. Some parameters of the actual operation of the flange connection of the crossbar to the column are taken into account. It is proposed to use conditionally rigid frame nodes. The reliability of a node is determined from the conditions of interrelated operation of individual elements. Calculated coefficients for designing this type of node are proposed. The paper presents flanged nodes with high-strength bolts. Such connections increase the manufacturability of structures. The use of these compounds requires the detailed study of their actual operation. During calculations, it is necessary to determine the relationships between the load-bearing capacity of the node elements. The measure of the statistical relationship between these values is calculated using the correlation coefficient. For steel frames, it is proposed to use conditionally rigid pliable nodes that provide a redistribution of forces between those loaded on crossbars and columns.

The objective of this work is mainly focused on the structures that support the facilities and machinery present in industrial plants. Service life extension of existing structures is one of the current objectives of the industry. The lay-out of the production has to constantly adapt to changes in production, variations in demand and new products. These changes of model or demand, usually imply important changes in the facilities and machinery and therefore in the structures that support them. Currently, these support structures are destroyed at each lay-out change, mainly because an easy reconfiguration of the support structures is not possible. To achieve service life extension of existing structures it is necessary to use easily reconfigurable, reusable and removable structures. Currently there are already solutions of structures that are removable and reconfigurable but mainly in aluminum beams. Nowadays, there are no definitive solutions for steel structures manufactured with standard shapes (standard steel beams). The use of clamp joints for steel profiles would be a very interesting solution and would allow the manufacture of completely removable and reconfigurable structures. This paper proposes and uses a methodology for the experimental analysis of the bending behavior of this type of joints depending on the length of the profile flange.

The Awash-Kambolcha-Hara Gebaya (AKH) Railway project is 389 km long single railway line over 54 bridges constructed in Ethiopia. The 5 m wide precast concrete composite deck rests on two built-up steel box girders side by side, supported on steel piers. The typical span is 46.4 m, formed by four 11.6 m segments using friction bolts. The construction of shallow pier and short bridges is performed using lifting cranes. For the construction of tall pier and long bridges, where the crane capacity is exceeded, incremental launching method (ILM) is used. Eight out of 51-bridges, ranging from 200 to 615 m continuous in length, are launched to provide construction ease and speed. The 11.6 m long steel box pieces are bolted at the assembly yard and launched over temporary bearings with an 18 m steel front nose. The longest bridge (B24) has 14 spans with 800 m horizontal radius, 2.42% slope and 45 m pier height. All launching equipment: back nose, pulling stick, guiding devices, temporary bearings and jack supports, are designed and manufactured locally in Turkey. The bridge design did not consider ILM method initially, so the authors worked with the already drilled existing web/flange splice bolt holes to connect the launching devices. In addition to the launching equipment, the permanent elastomeric bearings of all bridges are designed and manufactured in Turkey. The deck is supported on sliding elastomeric bearings longitudinally, to minimize seismic forces on the piers. Prestressed damping systems (PDS) are used in longitudinal direction to create a fixed point at one abutment in service state, while providing additional rigidity and damping during earthquake. The deck is fixed transversally using steel shear keys between the girders and the piers. The paper presents details about launching and bearing design of AKH railway bridges.

Variational methods of calculation are used to describe the stress–strain behavior of ribbed rectangular plates. The authors performed calculations for a plate with an unsupported load-free outer edge, based on the Ritz–Timoshenko strain energy method. In addition, a special approximating function that met all the contour conditions was found. The function was selected on the basis of the assumed wavelike pattern of plate flexures occurring on the edge. The calculation was based on the potential energy of elastic flexural strain for a round thin-walled plate pinched along the inner edge and on the potential energy of elastic flexure for radial ribs representing flexed beams. The obtained data allowed calculating the rigidity of a real object, i.e., a welding wire spool flange. This allowed providing recommendations on the design of spool flange ribs, avoiding any excessive elastic strains of the flange that resulted in the pinching of the wire loops located adjacent to it. The analysis of the obtained relationships showed that an increase in the number of stiffening ribs had a positive effect up to a certain value. After reaching this value, the effect of the increased number of ribs began to decline. Apart from that, the strain reduction occurred mostly due to increasing the stiffening rib height by 1.5–2 times of the flange thicknesses.

The article considers a method for studying the rate of changing the parameters of bearings’ technical condition in an induction motor, which is a drive machine in the vast majority of electrified agricultural production processes. The method of expert assessment and literature data show that when transmitting torque from the engine to the working machine using a mechanical clutch, a significant part of electric motors failures occurs in motor bearings. A radial clearance is used as a diagnostic parameter, representing the technical condition of bearings. In most reference books, its value is normalized according to rolling bearings. As a technical means for studying the rate of changing the radial clearance, a scheme of experimental stand and a device for creating a radial load on the shaft are presented. They simulate real conditions as accurately as possible. The developed stand with a climate chamber helps to provide the required ranges of air dustiness, humidity and aggressive environment which are typical for agricultural production. The presented device for creating a radial load makes it possible to provide a similarity to the process of transmitting torque using flange, cam-disk, rigid compensating and other types of mechanical clutches. As a result of the study, the polynomial equations reflecting the patterns, related to the changing rate of bearings’ radial clearance depending on the influencing factors, are presented.

There is growing interest and investment in the renewable energy industry with the goal of promoting eco-friendly growth globally. The proportion of wind power generation systems in the world’s renewable energy market is kept continuously increased and is known as 21.9%. In order to reduce the fossil-fuel power generation capacity, many countries enlarge the investment of the wind power generation systems. As the size of blade enlarges, the installation cost decreases and then the power generation efficiency could be increased. However, as the sizes of the blade and tower are enlarged, the weight and the wind load of itself might be increased. Therefore, it is necessary to develop appropriate components and their build-up technology that can guarantee the structural safety of the wind turbine. In this study, the stress applied to the tower flange when the wind turbine is operating is numerically analyzed. In particular, optimal design value for the aspect ratio of the tower flange was obtained, using fluid-structure interaction (FSI) method. The lowest von Mises stress had an aspect ratio of h1/h2 = 1.40. Numerical analysis of local stress of the tower and flange was calculated using the commercial code ANSYS 18.1.

Robotic roller forming (RRF) is a new dieless and flexible forming process using a roller mounted on an industrial robot to form sheet metal products by multiple passes with predefined tool paths. In this study, DP590 (dual-phase) steel sheets are formed to bent specimens having a right angle by RRF with three passes, and edge waves are observed at the flange of DP590 specimens. Finite element analysis is utilized to reproduce the edge waves. According to finite element simulation, longitudinal plastic strains are generated at the flange edges due to excessive tensile and compressive stresses, which results in severe edge waves. Two strategies are introduced to eliminate edge waves. One has to optimize forming parameters, and the effects of forming angle increment and moving direction of the roller on longitudinal peak strains at the flange edges are evaluated. Another strategy to eliminate edge waves is to apply laser heating in RRF, where the heating spot is 25 mm in front of the roller. Experimental results demonstrate that laser heating reduces forming forces, eliminates edge waves as well as the required number of forming passes.

Lubrication is widely used to reduce wear of wheel and rail profiles by decreasing the friction between the wheel flange and rail. The effects of wheel flange lubrication on the dynamic response of the wheel were investigated in this study, by analysing the responses of the adjoining bearing housing. The experiments were conducted on a 1/3rd scale twin disc rig, with a single wheel and a rail disc, which can have various speeds, loads and creepage. First, the theoretical modal parameters of the wheel were calculated by constructing a finite element model in order to obtain the shapes of interested modes. Then, Frequency Response Function (FRF) tests were conducted by exciting the rail disc on the laboratory rig and measuring the response of the bearing house. It shows that the FRF has a good agreement with the frequency domain signals of bearing housing responses when the rig is running under varying speeds. Last but not least, the responses of the bearing housing were measured when the rig was under four different constant speeds and three different loads. The tests were repeated for the wheel flange with and without lubricating grease. The results show that lubrication of wheel flange will result in a decrease of vibration amplitudes of the bearing housing in the frequency range of 6,000 Hz to 8,000 Hz when the rig under relative high loads. In addition, the lubrication will also lower some of the resonant frequencies of the wheel because of the oil film between the wheel and rail disc which was generated when the wheel flange was lubricated with grease.

Because of the low ductility of Ti–6Al–4V alloy at the temperatures between room temperature and 600 °C, fracture easily occurs during press forming. Hence, a method of press forming of Ti–6Al–4V alloy sheets at 300 °C was developed. In this method, the punch motion and blank holding force were applied separately to prevent fracture at the punch radius until the maximum punch load was reached, and the deep drawing process was demonstrated from the maximum punch load until finish forming to prevent the fracture at end of the flange. In addition, by applying the developed method, we were able to prevent the decrease in wall thickness at the punch shoulder, compared with that in press forming. As a result, warm press forming of Ti–6Al–4V alloy sheets at 300 °C was achieved without fracture of the formed cup or local decrease in the wall thickness by applying the developed method.

Rotary forming is an exciting route for forming flanges of different angles from seamless tubes of high-strength materials. True to its incremental nature, the process offers great flexibility, but the issues encountered are atypical and complex. One such issue observed in experimental trials is the internal buckling of tubes during specific instances of flange formation. The origin of this instability is non-trivial, and ordinarily, finite-element (FE) models fail to capture this instability. To analyse and understand the problem, systematic experimental trials were carried out using different tube thicknesses, tube materials, and tool kinematics. This paper summarises the results from a critical analysis to establish (1) a criteria for quantifying the instability and identifying the instances of its occurrence, (2) a validation methodology to fine-tune FE models for the process, and (3) use of FE models to understand the influence of tool path in the flange forming stage.

This paper analyzes the common practices of flange leakage check in piping design, compares the advantages and disadvantages of these methods, and propose a new engineering method considering bolt pre-tightening stress; gasket stress and piping stress, which based on flange installation requirements of ASME PCC-1 and equivalent Pressure. The key steps of this method and the matters need attention in engineering application are introduced by calculation example. The new method is scientific, reasonable, simple and easy to use approved by engineering practice. The method has reference significance for flange leakage check and flange installation in piping engineering.

In the paper, dependence has been obtained to calculate the contact pressures when drawing down the axisymmetric workpiece without a blank flange collet. The solution is based on the assumptions of the momentless theory of shells. The adequacy of the mathematical model is confirmed by experimental data for a narrow interval of forging blanks. The experiments have been carried out on a specially designed tooling to measure load cell deformation using a strain gauge. All the equipment used has passed metrological control. To calculate the meridional and tangential stresses on the torus-shaped portion of the matrix, dependencies were obtained that contain a term connecting the thickness of the workpiece with the value of the stresses arising during drawing, which more accurately describes their distribution on the drawing edge of the matrix. The expression for calculating the surface contact pressure during the drawing of a cylindrical part makes it possible to consider the friction stresses at the radius of the matrix rounding and calculate the drawing force. The obtained dependence differs from the conventional ones in its simplicity and clarity and can be used at the preliminary stage of choosing equipment for stamping. It is shown that the friction stresses between the contacting surfaces can be controlled over a wide range while achieving a significant change in the stress state and the distribution of deformations in the volume of the workpiece.

For the manufacture of cylindrical rods with a thickening (flange) on the end part of difficult-to-deform alloys, the method of upset of the end part of bar stocks in the short-term creep mode with a viscous material flow looks promising. This process lacks comprehensive study. Therefore, this paper presents a theoretical analysis of this process. The energy calculation method is used. We consider the process unsteady. The state of viscoplasticity is accepted under an axisymmetric deformation scheme. The flow diagram and relationships for calculating the kinematics, pressure, and damage to the workpiece material during heating upsetting are presented. The calculations were performed for the landing of the body blank of the cone of a product made of high-strength aluminum alloy and titanium alloy at temperatures and speeds that ensure the viscoplastic flow regime. The process diagram was taken as plain one. In the course of mathematical modeling, an expression is obtained for estimating the pressure. The research revealed the influence of technological modes to pressure changes of the studied process. The rational parameters of the upsetting, allowing to achieve minimum pressure values, are established.

The book in question pertains to some selected issues regarding composite steel and concrete structural members. It contains information on the state-of-the-art designs and constructional technologies in the field of composite structures in Slovakia and abroad. Particular attention is drawn to deck bridges with encased filler-beams to show some new possibilities and challenges in such structures. This type of construction is well-suited to bridge obstacles over short spans, and it is currently exploited to bridge sluices, culverts, rivers, roads, and other obstacles as wide as up to 18 m. Still, it is only the I-sections that are encased as the rigid reinforcement in most cases. Another purpose of this work was to bring a new progressive modified and experimentally verified shape of steel section into the civil engineering world. The steel box section provides an improved method of composite action/shear connection, ensured by the holes made both in the top flange and the webs of the steel beam. Another advantage of the steel box section rests in its exceptional flexural stiffness, which can guarantee that the beam will bear the dead weight of the fresh concrete in the construction process if necessary.

Inclined rotary forming (IRF) combines bending and axial compression with rotation and is employed for forming flange shaft-structured parts from round rod billets. Although the forming load is smaller than the one in conventional processes, cracks may develop during this process. However, it is difficult to predict the onset of cracks using conventional ductile fracture prediction equations. In this paper, an equation for predicting ductile fractures is proposed, which considers anisotropic ductile damage. The proposed equation is expressed as a second-rank tensor resulting from the inner product of the stress tensor and the strain increment tensor. Referring to the previously published results on the compression of cylindrical specimens, the difference between diagonal and longitudinal sidewall cracks was clarified by considering the anisotropy of ductile damage. The proposed equation was then applied to the IRF process, wherein diagonal cracks developed at the outer rim of flange. Consequently, it was possible to estimate the requirements for reducing diagonal cracks by controlling lubrication conditions.

Full-guided surgery may be of enormous help, especially in full-arch edentulous cases. Due to the esthetic and hygienic challenges in full-arch crown and bridge prostheses, the use of a removable denture, such as an overdenture supported by a bar, telescope, or individual attachments, may be recommended in individual cases. A temporary tooth setup without the anterior labial flange can be used as a diagnostic tool to plan either a removable or a fixed full-arch prosthesis.

Recent earthquakes highlighted that, conventional steel moment frame (SMF) shows brittle failure due to the seismic actions. Greater damages are due to the stress concentration at the interface of beam and column. A number of improved beam to column connection design strategies have been proposed. Reduced beam section (RBS) connection was introduced as a safety approach to reduce stress concentration at the panel zone. RBS promote the formation of plastic hinges within the reduced beam section of the beam at a specific distance from column face. The finite element analysis of steel beam-column connection arrangement was carried out for studying the strength behavior of beam column joint. In this paper cyclic analysis of bolted steel beam-column connections with RBS were using finite element analysis software ANSYS 16.1. The cyclic behavior of bolted beam column joints with and without RBS techniques are investigated. Cyclic behavior of variable configuration of reduced beam sections was also examined. From the analysis, it is observed that the specimen with RBS dissipates more energy than the conventional moment connection. Connection region remained in the elastic area due to plastic hinge formation in the RBS zone. The applied RBS geometry protects the connection and its components (endplate, column flange, bolts, welds) from failure. To investigate the effectiveness of RBS in inclined beams, 3D finite analysis is performed on the frame with a slope of 10°, 20°, 30° from the orthogonal.

Critical bolted connections exist in many engineering structures, from pressurized pipelines to wind turbines. Often there are legal demands for maintaining necessary bolt tension in such joints to prevent failure. The available tools for tightening makes it challenging to obtain the correct tension in a bolt, as well as subsequently checking if a bolt is in fact tightened to the correct level. Recent work proposes to use vibrations for estimating tension in a bolt. Estimation is possible by measuring and analysing transverse natural frequencies and damping ratios induced by e.g. a transversal or longitudinal hammer impact on the bolt itself. The work so far has focused on a single bolt. Most bolted joints consist of many bolts, e.g. a flange connection often has a ring of almost identical bolts. Identical bolts, with almost the same tension, will also have very similar boundary conditions and thus almost the same natural frequencies. If there is only very light damping between two adjoining bolts, a frequency response measured on one bolt after an impact might include the vibrational response of both bolts (the coupling might even be so strong that the two bolts cannot be viewed as entities on their own) leading to the question: How to separate which frequencies belong to which bolt?

A standard finite element analysis of individual components in aero engine and other systems shows a high accuracy compared to experimental measurements of the system response. However when it comes to assemblies, the conventional linear approaches fail to deliver good accuracy. This is due to the uncertain physical phenomena in the contact interface of the joints. A nonlinear contact problem is introduced by the joint and influences the overall dynamic behavior of the engine assembly. Therefore, the linear dynamic models must be coupled with nonlinear analysis of the assembly to investigate the accurate dynamics of the nonlinear system. Flanges are widely used joints that represent the main source of nonlinearities in assemblies. In this study, a finite element simulation of two bolted flanges is considered to identify the nonlinear behavior of the bolted flange joint caused by the presence of friction in contact interfaces. A detailed model of a bolted joint was built in ANSYS in order to evaluate the energy dissipated in a bolted joint and therefore provide accurate modeling of joint interfaces. Due to the high cost of the detailed model, an equivalent model was derived and predictions from this model are compared to the detailed model results in order to provide a robust model for designing bolted joints.

The article investigates the influence of the flexibility of the rigid node of connection of the crossbar with the frame rack on the stress-strain state of the elements under the action of vertical evenly distributed load on the crossbar and horizontal evenly distributed load, applied to the frame racks. Since the bolts in the flange connection are stretched by the action of the bending moment, the nodes open, that is become partially hinged. Knowing some initial parameters of ideally rigid knots, it is possible to establish, what influence their change will have, both on the design scheme of a frame as a whole, and on its separate elements. The initial parameter method was used to determine the influence of the flange opening angles on the stress state of the elements. The proposed method allows us to determine the rigidity of any bolted flange connection, taking into account its actual operation. Taking into account the pliability of the nodes and, as a consequence, the structure as a whole, allows us to unload the elements and calculate the additional resource bearing capacity. In addition, the technique allows you to adjust the stiffness of the bolted joint by changing the diameter of the bolts, their number, distance between them or changing the thickness and height of the flanges, as well as use additional material resource by reducing the maximum stresses in the calculated cross sections.

Consider a cantilevered beam with a stiff crossbar at its outer tip, as illustrated in Fig. 10.1. At either end the crossbar is subject to a transverse force \( F \). This will cause a twisting \( \theta \left( x \right) \) along the entire length of the beam. The force effect that causes this twisting is the torsion moment \( M_{x} \), which in this particular case is equal to \( 2Fa \). The way a line-like beam type of system will carry a torsion moment depend on the type of cross section, as illustrated in Fig. 10.2. In a circular or rectangular tube, the torsion moment will cause a constant shear stress flow around the entire cross section, as illustrated in Fig. 10.2.a. In a thin walled open cross section, the torsion moment will cause two shear stress effects, as illustrated in Fig. 10.2.b. First, there will be a shear stress flow in each of the plate elements within the cross section. This shear flow varies linearly across the thickness of each of the plate elements. This effect is called St. Venant torsion. Secondly, there will be a constant shear flow across each of the outer flange elements, an effect which will cause the flanges to bend in opposite directions as illustrated in Fig. 10.3. This effect is called warping torsion. As can be seen, the effect of warping is not only shear, but also normal stresses due to bending in the flanges. In general, the torsion moment stress effects will be a combination of St. Venant torsion and warping. We shall in the following assume elastic, homogeneous and isotropic material behaviour. We shall take it for granted that any cross section is thin walled or else compact.

Nb-microalloying has a significant effect on microstructure evolution during hot-rolling. Metallurgical benefits of niobium are associated with the formation of Nb(C, N) in ferrite and austenite, retardation of austenite recrystallization, and further austenite to ferrite phase transformation. Precipitation and microstructure control are therefore important features to achieve better strength and toughness simultaneously. Effects of hot-rolling conditions on strength and toughness are of great interest because the rolling parameters, e.g., temperature, roll force, and cooling rate, contribute to strengthening mechanism of Nb-microalloyed steels. Grain refinement is the most practical way to enhance the niobium-bearing steels by strain-induced precipitation hardening below the non-recrystallization temperature. This rolling research involves residual stress variation associated with parallel-flange section geometry. Therefore, a repetitive hardening–softening mechanism could be an important feature to predict the final mechanical properties. Computational and experimental analysis has been used to determine flow stress according to the temperature change in hot-rolling. The recrystallization behavior is experimentally observed through the multiple rolling.

With the development of heavy-load locomotives, the wheel wear increases remarkable due to the excessive dynamic force in wheel and rail. For locomotives, the wheel-axle traction is relative large and has significant effect on the rail wheel creepages, which have a direct influence on wheel rail wear. To research the influence on wheel rail wear by traction, a model has been built to calculate the wear of an electric locomotive when running at a constant speed and starting condition, which considers the transmission system based on Archard wear model. The wheel wear is calculated according to a certain actual line, and compared with the measured data, in order to research the abnormal wear on wheel flange during the condition of normal operation by the calculation model of tread wear of the locomotive. The results show that when the locomotive runs at a constant speed of 260 thousand km, the traction increase by 80 kN on the basis of 40 kN and 120 kN, the account of wear increase by 0.74 mm and 1.74 mm respectively; and with the comparison to the measured data, the calculated results are in good agreement with the experimental results, the accuracy of the model has been proved; reducing the lateral displacement of the intermediate wheelset and the side lubrication of rail can greatly reduce tread wear, when the lateral displacement of the intermediate wheelset is changed from 15 mm to 10 mm, its cumulative wear reduce by 15.4%; and the maximum cumulative wear of first, second, and third wheelsets are decreased by 13.40%, 21.32% and 6.46% after side lubrication of rail respectively.

Wheel flange wear often occurs on metro trains when they negotiate sharp curves, especially for the poor matching of wheel and rail profiles or lack of lubrication, which evidently increases the maintenance and replacement costs of the wheelsets and rails. The reason for severe flange wear of the original wheel profile on one metro line in China is investigated through field experiments and numerical simulations. An optimal wheel profile is presented based on the rolling radius difference (RRD) to improve curving performance of the vehicle and mitigate flange wear. A wheel wear prediction model, coupling a metro vehicle dynamics model considering multipoint contact with a long-term wear simulation model, is developed, which is validated using field measurement results. The capability of the optimal wheel profile is numerically evaluated. The results show that the improper wheel-rail profile matching of the original wheel profile is responsible for wheel flange wear. The large proportion of sharp curves and the abnormal rail cant also contribute to flange wear. The optimal wheel profile proves to work fine in terms of wheel/rail contact geometry and wear performance. The wheel flange wear of the optimal wheel profile is decreased by over 60% compared with that of S1002 profile.

Owing to the existing of many sharp curves, the fast wear of wheel flanges has become a big problem in a Chinese tramway. To reduce the wheel flange wear rate and increase the lifetime of tram wheels, the authors have conducted extensive experimental measurements and numerical analyses. The long-term tracking measurement concentrating on the natural wear process of the tram wheels have been carried out. This paper reports the flange wear characteristics and developing law of the tram wheels based on measured data. An optimal wheel profile for the tram vehicle was proposed based on a large number of multi-body dynamics simulations. The wear and curving performances of the original and optimal wheel profiles were compared through dynamics simulation. The results show that the optimal profile can improve both the wear and dynamic curving performances of the tram vehicle.

We report the design, manufacture, and testing of the Michell-Banki turbine by using the hydraulic data of the Ambato - Huachi - Pelileo water irrigation channel in the Tungurahua province in Ecuador. The turbine has the blade, impeller, flange and shaft that are purely plastic materials because they will be subject to the action of water and thus be able to extend the life of the components. For an optimal design it was considered an efficient alternative, which is the manipulation of the turbine, it should be portable and as light as possible. When performing the tests, it was determined that there is an error around 14% between speed and torque calculations, while the greater efficiency of the turbine is at the exit of each oval of the channel. The main contribution of the present work is to provide the required promise component in a Pico-Hydro that is expected to be implemented in the water irrigation channel. Also this work aims to provide several benefits to the society bordering the irrigation channel, such as generating energy for self-consumption as a contribution to the lighting of the channel at no cost to the people.

The first resurfacing component for the distal femur developed in the 1950s, the Massachusetts General Hospital femoral condyles, was a close replica of the anatomic geometry. In contrast, the first two cemented metal femoral components of an artificial knee, invented in the late 1960s and early 1970s, were far from anatomic. The first was Gunston’s hemi-disc which fitted into a slot cut into each femoral condyle. The second was Freeman and Swanson’s hemi-roller which fitted over the flat resected surface of the distal femur. This idea of using straight bone cuts for fitting the femoral component was a simple but a major step forward. After 1970, many different femoral component designs emerged, with and without a patella flange, some geometrically simplified. The Ewald and Seedhom knees, being shells of the exact anatomic surfaces, were not easy to fit surgically, while manufacture was difficult and expensive. Other designs were of a simplified shape, with straight facets for bone fitting and with geometrically defined surfaces. These designs included the Townley, and the Total Condylar designed by Walker, Insall, and Ranawat. By then it was realized that an integral patella flange was required on the femoral component. This led to the invention of a resurfacing component for the patella itself. It was found that a dome-shaped patella “button” was the most practical shape which allowed for tilting and motions in multiple directions without edge loading.

This paper presents wheel/rail (W/R) contact friction coefficients and creep curves measured by using the Rolling Contact Fatigue Simulator (RCFS). Measurements showed W/R contact friction coefficients and slopes of the creep curves during the transition from partial slip to full slip increase with the decrease of contact stresses under dry contact conditions. Even though the friction coefficient is smaller due to water lubrication, it has little effect on the creep curve transition slope. NUCARS® (NUCARS® is a registered trademark of TTCI) turnout simulations showed that friction coefficient variation with wheel loads may have detrimental effect on flange climb derailment for the case of new wheels running on new rails. Measured W/R contact creep curves under different wheel load conditions are recommended for flange climb derailment investigations.

In this work a smoothed computation of the two-point wheel-rail contact scenario using the simplified Knife-edge Equivalent Contact constraint method (KEC-method) is presented. The procedure that considers the continuous KEC solution of the wheel-rail contact with equivalent profiles (equivalent wheel and single-point rail) proposes a smoothed transition between tread and flange contact in order to reduce the numerical instabilities that abrupt forces in flange may produce when flange contact occurs. This smoothed transition considers a small region in the wheel close to the two-point contact scenario. When contact happens in this region, tread normal contact force is transformed into two normal contact forces: one acting on the wheel tread and the other one acting on the wheel flange where different algorithms for this force transformation are proposed. However, in order to maintain the dynamics of the vehicle, the resultant normal force acting on the wheelsets, which is obtained as a reaction force of the constraint KEC-method, is kept after the force transformation. This procedure is applied to the numerical simulation of a single wheelset and results show that numerical instabilities of the two-point contact scenario using constraints are avoided.

The evolution of three different types of initial wheel profiles in a train with motor and trailer bogies has been investigated. Therefore, wheel profile measurements have been carried out regularly within a wheel re-profiling interval. The wear volume develops in average linearly as a function of mileage. The analysis show, that the initial profile shape and the position where the wheels are located along the train does not significantly influence how the wear volume develops. Furthermore, only little differences were observed when comparing motor and trailer bogies. The same is true for the wear distribution along the profile at the end of the re-profiling interval, although the flange wear of the wheels in the motor bogies is slightly higher. In contrast to this findings the equivalent conicity behaves different. Its development as a function of mileage depends highly on the initial profile shape. Furthermore, it always shows a non-linear s-shaped characteristic. The results of this work are an important basis to develop an advanced methodology which is able to predict the evolution of wheel profiles in an accurate but still efficient way.

The running safety of a railway vehicle against flange-climb derailment is evaluated with the derailment coefficient. A monitoring bogie, which can measure the derailment coefficient during commercial operations, has been developed and condition monitoring of derailment coefficient has been realized. However, the critical derailment coefficient is determined by the friction coefficient between the leading outside wheel flange and rail, which changes due to wayside rail lubrications. In order to evaluate the running safety more accurately, the present paper proposes an estimation method of the friction coefficient of the leading outside wheel flange utilizing the multibody dynamics simulation. By changing the friction condition and repeating simulation in sharp curves, relationship between the given friction coefficients and the calculated wheel/rail contact forces is derived, and look-up table is created from the results. The friction coefficient of the outside wheel can be regressively estimated by inputting the measured contact forces collected with the monitoring bogie into the look-up table. This paper also considers the influence of wheel/rail profiles on the proposed method and presents a modified look-up table made from simulations with the measured wheel/rail worn profiles.

The paper deals with the design of production and evaluation of surface quality and geometric deviations of shape and position of flange component intended for driving of robotic arm of three-axis robot by CAM programming. The flange is made of cylindrical and end faces and is made on a two-axis CNC lathe Leadwell T5. Surface quality measurements were performed on a Mitutoyo SJ 400. Geometric shape and position deviations were measured and evaluated on a Roundtest RA120. Autodesk Inventor 2019 was used for flange modeling, and HSM PRO 2019 was used to generate the NC code. For diameter 62H8, Ra = 0.95 μm, and Rz = 4.95 μm. The roundness deviation for D = 100 mm is 56.1 μm and for D = 62 mm is 57.7 μm. The misalignment deviation of these diameters is 2.8 μm.

Rail transport performs significant volumes of transportation work and is one of the largest energy consumers in all developed countries of the world. Most of the energy used in railway transport is spent on train traction. To improve its energy efficiency, it is advisable to carry out measures aimed at reducing the resistance to movement of trains. A special contribution to the creation of resistance to the movement of rail vehicles is made by processes associated with the interaction of the wheel flange with the rail in the case of two-point contact, when additional parasitic differential slip occurs in the ridge contact. It is impossible to avoid this slippage without changing the traditional structural scheme of the wheel (with monolithic production of its supporting and guiding surfaces). The work considers the kinematics of the movement of the ridge along the lateral face of the rail head during rolling of the wheel of the rail carriage. An analytical expression is obtained for the approximate determination of the length of the wheel flange slipping path along the lateral face of the rail head, taking into account the conditions of its contact with the rail. The features of the kinematics of the wheels movement of the traditional and perspective (with the possibility of independent rotation of the bearing surface of the wheel and its guide surface) of the design scheme are analyzed. The levels of work of the friction forces in the ridge contacts of the wheels of different design schemes are determined. The results of the analysis suggest that the use of wheels of a perspective design in the undercarriage of rail vehicles can significantly reduce the kinematic resistance to movement and wear of the contacting surfaces of the wheel and rail by reducing the slip of wheel crests along the side faces of the rail heads.

The paper presents the results of a study of the process of axial rotary forging by a conical roll performing a complex movement. In addition to the usual rotational motion the forming roll moves progressively at the initial moment of rotary forging and changes the angle of inclination relative to the workpiece at the final stage of the process. The technology was designed for the manufacture of axisymmetric parts with developed internal flanges, when the usual rotary forging process is limited by the loss of stability of the tube blank. The proposed technology ensures the stability of the workpiece during processing, and allows you to get a wide inner flange. Computer simulation of technology in the complex Deform 3D made it possible to determine the rational values of the parameters of the tool movement.

The article discusses four different options for entering the guide wheels to the guard rail bends: when driving along a straight path of railroad switches with a straight or curved frog, the rolling stock has a free arrangement in a track; the flanges of its wheelsets either fall into the guard rail gutter without hitting the bends, or run into the bend at any point in it; when moving against the direction and along the direction when leaving the frog curve of the same direction with the railroad switch curve, the front axle of each bogie runs along the outer wheel flange onto the outer rail; the rear axle, depending on the insertion mode, is either pressed against the inner rail, or occupies an intermediate position, or pressed against the outer rail; in case of a directly movement from a straight path to a curved frog, the rolling stock is in a track in a free position and a impact is possible either in the working face of the core, or in the guard track bend; when directly entering the railroad switch with a curve, the reverse railroad switch impact with the front axles of the rolling stocks or bogies will occur in the check rails, the wheels of the rear axles can hit the bends of the guard rails. In all variants of the impact on the bends of guard rails when moving on the side track, they are determined by the number of strokes, the mass participating in the impact, the angle of impact, as well as the amount of transverse displacement of the rolling stock when hitting a guard rail, characterizing the work extinguished by the guard rail, and the smoothness of movement in the frog zone, methods calculating the determination of the length of the straight bends of the guard rails with straight frogs, determining the length of the rectilinear bends of the guard rails with curved frogs, determining the length of the curved bends to guard rails having a constant angle of inclination to the roadway with curvilinear frogs. Guard rails of the sideways of railroad switches take significantly greater impacts than guard rails of the forward direction. The only way to reduce the impact on these bends is to reduce the impact angles and collisions. For railroad switches with curved frogs, as well as for railroad switches with straight grogs with a railroad switch curve extending to the guard rails zone, it is best to use guard rails with curved bends that have the smallest length and provide the most secure entry to the bend.

Cardan shafts are commonly used when the drive and driven shafts are not coaxial but are still parallel. If the distance between the shaft changes, then the length compensation is moved under the influence of torque, and the resultant friction causes an axial force to be generated between the tooth flanks in the spline. This movement can be caused by the deformation of the frame or misalignment of shafts. The magnitude of this axial force is important for the design of other machine parts in terms of service life. This article deals with the measurement of torque and axial force on cardan shaft located on machine drive. This was done to verify the magnitude of the axial forces and torque at the run of the machine due to the fatigue fracture of the bolts at the cardan flange. Article describes the methodology of measurement, used equipment, and evaluation method. Measured values of the axial force are compared with theoretical calculations of axial force according to the manufacture of cardan shaft.

Recent earthquakes have shown that steel moment frame (SMF) with weld connections are so brittle. According to the studies conducted, great damages are due to the cracking of the weld between the beam flange and the column face and inducing concentrated stresses in this area. A natural way to solve the problem is to reduce the ductility demand on the welded areas by reducing the stress concentration level. A useful approach to reduce the stress concentration at the panel zone could be the use of reduced beam section (RBS). A portions of the beam flanges are trimmed away in the region adjacent to the beam-to-column connection (Han et al. in J Constr Steel Res 70:256–263, 2012) [1]. The RBS can be viewed as a ductile fuse that forces the formation of the plastic hinge away from the joint so that much of ductility demand on beams may result from the RBS instead of the welded beam-to-column interface. RBS connection is widely investigated and used in US, Japan and Europe. In this study moment connections with different shape of reducing beam flange have been modeled using ANSYS and compared with each other during cyclic behavior. The sloped moment connection with best configuration is analyzed to find the cyclic response of the connection (Shen et al. in Eng Struct 22:968–983, 2000) [2].

Steel frames with column and beam connections welded together show brittle nature during earthquakes. According to previous researches, the major damages were the cracks developed in the welded portion between the beam flange and the face of the column. Such cracking results in accumulation of unwanted stresses in the welded region. Reduced Beam Section (RBS) method is an effective way to limit the accumulation of stress in the vicinity of beam column joint. Out of different advanced beam to column design approaches developed after the earthquakes in Northridge in 1994 and Kobe in 1995, the reduced beam section connection has proven satisfactory ductility levels in numerous tests. The use of RBS in beams to column connections results in the formation of plastic deformations at a certain distance from the beam column joint. In the present study new types of reduced beam sections have been modeled using ANSYS 16 software by trimming the beam flange in different pattern and is compared each other under cyclic behavior. The results obtained from this study have shown that the reduced beam section with same holes dissipates more energy than other type of connections.

The area of sealed flange connections of pressure vessels often encounters critical operating states that are defined by particular load conditions. These loads are exhibited from assembly stage, through pressure testing, to operation of the pressure vessel. The issues arising in assembly conditions alone are complex and significant. However, this article discusses the problematics of flange joints in subsequent conditions. Specifically, it is examining the effect of temperature on the bolt pretension. Stiffness calculations for machine parts which are constantly exposed to high temperatures at continuous exertion of force pose a significant level of complexity even nowadays. For calculations of pre-stressed bolt connections, the computations are even more complicated. This is given by the fact these are highly complex components that are almost always extremely stressed. However, the requirements for critical flange joints are even higher. There are not only bolts strength requirements, but strict leak rate requirements of gasket joint as well. This article provides a basic description of the effect of temperature on bolt pretension. Its theoretical basis is complemented by concrete examples from practice. Subsequently, one of the examples is subjected to FEM analysis. Finally, the possible ways of partial elimination of negative thermal influences on flange connections of pressure vessels are demonstrated.