Bearings are the supporting elements of bridges. They perceive vertical and horizontal loads from the bridge span. Spherical bearings are one of the construction common types. The material and configuration of the anti-friction layers determine the bearing performance. The paper performed the contact deformation analysis of spherical bearing elements at a nominal vertical load of 1000 kN. The six types of the spherical sliding layer material are considered: ultra-high molecular weight polyethylene (UHMWPE) from three different manufacturers, modified polytetrafluoroethylene (PTFE), and composite materials by PTFE with two different forms of reinforcing bronze inclusions. Young’s modulus, Poisson’s ratio, and strain curve are obtained experimentally for spherical sliding layer materials. Paper considered the influence of the sliding layer material on the contact parameters and deformation characteristics of the structure with a standard interlayer thickness by 4 mm. Research observed significant the composite interlayer deformation and the appearance of “no contact” zones on the mating surfaces. The option of increasing the sliding layer thickness up to 6–8 mm is considered. A decrease is observed in the maximum level of contact parameters by increase of the sliding layer thickness. The influence of the anti-friction layer materials becomes insignificant on the bearing deformation with an increase of the spherical sliding layer thickness.

The novel results reported here present qualitative and quantitative regularities of the deformation behavior of a spherical bearing with a different location and inclination angle of the antifriction layer. A number of topical problems encountered during the assessment of the performance bearings are considered in the work. The spherical bearings of the bridge span are investigated. Structures are load-bearing elements of transport systems. They perceive thermal power loads from the bridge span. The temperature problem is not considered in this study. In this paper, a comparative analysis of the bridge spherical bearing operation at different antifriction layer locations was performed. Two bearing geometries are considered: the interlayer is pressed in a spherical segment (classical geometry); the interlayer is pressed into a recess located in the lower steel plate. The six modern antifriction materials considered proved suitable to some extent as contact unit sliding layers for various purposes. Additionally, the influence of the inclination angle of the antifriction layer end face on the structure operation for all sliding layer material variants was analyzed. It has been established that the bearing design with an interlayer in the lower steel plate has a more favorable deformation behavior. Changing of the inclination angle of the antifriction layer end face leads to a decrease in the maximum level of contact parameters and deformation characteristics for all the considered structures.

The load on transport and logistics systems is increasing every year. This is due to car park growth around the world. Thus, increasing bridge structure durability is an urgent task for bridge-building companies. This study analyses the contact deformation of spherical bearing elements through an anti-friction polymer layer with different geometrical configurations of recesses for the lubricant, i.e., annular grooves and spherical holes. The material of the anti-friction layer (a modified polytetrafluoroethylene (PTFE)) is modelled within the framework of the deformation theory of plasticity. The procedure of automating the numerical model construction depends on the input parameters, including the thickness of the layer, the basic geometrical parameters of the recesses for the lubricant, and the distance between the rows of recesses, etc. The influence of the arrangement of filling sliding anti-friction layers on recesses for lubricants in the form of spherical holes on the contact deformation behaviour of bridge bearings has been considered. The reduction of lubricant volume in the sliding anti-friction layer with the geometry of recesses in the form of spherical holes ranges from 26 to 48.4%, depending on the filling scheme, has been found. In this case, structures with lubrication recesses in the form of spherical holes have several advantages, including a more uniform distribution of contact parameters in the interface areas of the steel plates with the anti-friction layer, reduction of the maximum level of the plastic deformation intensity, displacements along the normal relative to the free end of the sliding layer, and the settlement of the bearing.

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The results of experimental studies of the modern antifriction polymer materials and composites based on them are presented in the work. The 6 most promising materials for use as antifriction coatings and interlayers in friction units of critical structures were selected from a set of materials: bearings, expansion joints etc. The deformation theory of elastic-plasticity for the active loading case is chosen to describe the polymer behavior model based on the experiments results in a first approximation. Compression charts are defined for the selected materials. Numerical models of constrained and free compression experiments are constructed. The series of numerical experiments established that the contact pressure level of composite materials is 25-40% lower at a single level of deformation. UHMWPE and modified PTFE under uniaxial deformed conditions state have an almost elastic behavior with weakly nonlinear hardening and in test problems their deformation behavior has small differences.