Failure assessment and life calculation of welded joints based on parameter table optimization algorithm

Abstract

In order to reduce the potential safety hazards in the operation of rail vehicles, a new parameter table optimization algorithm based on the particle swarm optimization algorithm is proposed to carry on the failure assessment and fatigue life calculation of welded joints. This algorithm reduces the number of iterations by adding connection pools to connect the parameter selection database. In addition, based on this algorithm, combined with Python language and BS7910 standard, a calculation program for failure assessment and fatigue crack growth life is written. The algorithm program is validated by taking the commonly used T-type, butt, and lap joints as examples. In terms of failure assessment, the calculation results of the algorithm program are securer and more conservative, and the safety accuracy of the algorithm program is improved by 8%–12%. In terms of fatigue crack growth life, the error between the calculated value of the algorithm program and the test data is within the engineering allowable range. At the same time, the algorithm program can give the evaluation calculation results more intuitively and quickly, which provides a reference for the failure assessment and life calculation of the welded structure.

Modification and application of notch equivalent stress method for fatigue assessment on welded structures

“…Dong (2001) used the finite element method to calculate the nodal stress and bending moments, obtained the structural stresses at the welded position based on the free-body section method, and derived the equation for the equivalent structural stress ΔSs based on fracture mechanics as the theoretical basis, combined with the stress parameters associated with fatigue life. Wang et al (2023) proposed a parameter table optimization algorithm based on particle swarm optimization algorithm for failure assessment and fatigue crack growth life calculation of welded joints based on the principle of fracture mechanics. Gao et al (2013) studied the presence of notch stress in the direction of crack growth in steel welded structures at the location of the weld.…”