The fatigue behavior and fatigue reliability analysis of vibroseis baseplates based on fracture mechanics

Due to harsh working conditions and complicated external load, fatigue crack and fracture failure of the vibroseis baseplate usually occur during load cycles. To improve the fatigue resistance and extend the service life of the baseplates, this article studies the fatigue behavior of the baseplate materials and analyzes its fatigue reliability using fracture mechanics. Initially, the baseplate fatigue life is predicted by the crack propagation model based on the Paris’ and Forman’s laws. Three welded characteristic specimens of the baseplate are designed and fatigue is tested under a three-point bending load. The strain value and the crack propagation loading cycles are recorded during the test. Meanwhile, the crack propagation, damage, and fracture region of all the specimens are observed and tracked by scanning electron microscopy, which determines the fatigue damage mechanism of the baseplate. The fatigue reliability and parameter sensitivity analysis have been the subjects of previous research due to the randomness of the fatigue parameters. Finally, the most important random parameters are optimized based on the reliability analysis. As a result, the fatigue life reaches its maximum, and the reliability increases by 1.8%, resulting in a significant improvement in the fatigue resistance ability.