Stress redistribution and failure of mobile machines frame during propagation of crack-like defects

•The patterns of changes in the stress–strain state of the trailer frame during the simulation of crack growth were investigated using the finite element method.•It was established that a crack in the load-bearing element of the frame leads to the frame warping and an increase in stresses in the undamaged frame elements.•The influence of the existing crack in the frame on the subsequent fatigue strength of the undamaged elements of the frame structure was analyzed.•The results of the stress–strain state of structures with a crack are compared with experimental data. The peculiarities of the effect of a notch imitating the development of a crack in the frame longitudinal member of the trailer on its stress–strain state are considered. The research was carried out using the finite element method and the obtained results were compared with known experimental data. Good convergence of simulation results and experimental data was established. The theoretical principles justifying the redistribution of forces between the elements of the frame, which is a statically indeterminate system, when a crack propagates in one of its elements, are given. As a result of modeling, it was established that when one of the frame longitudinal member develops a defect, there is a redistribution of internal forces, an increase in stresses and deformations in the neighboring undamaged spar. The factors that can lead to a decrease in the durability and reliability of the mobile machines frames are indicated.