STRENGTH AND DEFORMATION ANALYSIS OF A THREE-LAYER ORTHOTROPIC PLATE

The article analyzes the advantages and disadvantages of three-layer orthotropic slabs. It is shown that when developing the design of such slabs, it is necessary to work out the technology of connecting the elements in the structure. The use of laser welding for connections is effective for connecting elements of small thicknesses. Such welding of sheet elements with a thickness of 12–50 mm has a number of limitations, and the strength characteristics of the joints have not been sufficiently studied. Therefore, when developing slabs with a large load-bearing capacity, it is advisable to design a steel three-layer orthotropic slab using electric arc welding. It is shown that a large number of intersections of welded seams in the joints of elements of such slabs requires performing work using techniques that reduce welding deformations and prevent cracking in such slabs under low operating temperatures, quasi-static and variable loads. The stress-strain state analysis of the slab has been completed. The model and full-scale slabs are tested for transverse loads. It is found that due to welding deformations, deviations of the actual geometry of the slab from the design one appear. This can explain the differences in the experimental and calculated values of vertical displacements. No failures of the slotted welds used to connect the elements were detected during the slab testing. Cracks at the maximum load on the slab model appeared only in the welds located along the perimeter of the cover slab. It was found that the welded 3-layer slab has intersections of welds in which cracks originate. This requires identifying crack-hazardous zones in the slabs using non-destructive testing methods and experimental research into the strength of structural forms containing structural and welding stress concentrators.