Strength and Deformation Analysis of Three-Layer Orthotropic Slab Using the ANSYS Software Package

The paper 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 for connecting elements within the structure. The use of laser welding is effective for joining 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, in the manufacture of heavy-duty structures, three-layer orthotropic steel plates are often used; the plates are connected to each other using electric arc welding. Current experience shows that a significant number of weld intersections at joints requires compliance with a certain technological sequence of work to reduce deformations that occur during welding and prevent the occurrence of cracks during operation in areas with negative temperatures, as well as quasi-static and variable loads. An analysis of the stress-strain state of the slab was carried out using the ANSYS multifunctional software package. The model and full-scale slabs were tested for lateral loads. It has been established that due to welding stresses, it is possible that the actual geometry of the slab may deviate from the design one. By comparing the results of vertical movements of theoretical calculations and full-scale tests, the results of deviations are substantiated. After conducting experiments and inspecting the test samples at the points where the elements are connected to each other, the destruction of the slotted seams was not detected. When the maximum load applied to the slab model was reached, cracks were detected in the welds located along the perimeter of the cover slab. It has been revealed that in the design of welded three-layer plates, in the places where the sheets intersect, the weld is a concentrator of defects. The use of manual or semi-automatic welding contributes to the initiation of cracks under variable loads and operation at low temperatures. This problem requires the identification of crack-dangerous zones in three-layer slabs using non-destructive testing methods and experimental studies of the strength of various technical solutions using structural and welding stress concentrators.