Vol.20, No.3, 2020, pp. 263–279
UDC:

The application of linear elastic fracture mechanics approach in analysing fatigue crack growth rates in welded high strength steels is reviewed. A systematic literature review is undertaken in order to demonstrate the efficacy of small test specimens in testing welded structures for fatigue crack life. Experiments demonstrate that use of conventional specimen testing for probabilistic fatigue crack growth rate in welded steel might overlook the effect of induced residual stress. Firstly, an ideal fatigue crack propagation life prediction technique for welded high strength steels that includes fatigue crack driving force with established methods is analysed, since real geometries are difficult to properly represent in analytical and numerical applications. In the second part are investigated essential experimental cases of welds in high strength steel and the load spectrum and geometry for fatigue crack growth rate based on LEFM. The third part covers the current state of LEFM model for fatigue crack growth rate (FCGR) using FEM. This approach considers the induced residual welding effect for the purpose of reliable integrity assessment. This review also focuses on the impact of test specimen inconsistency on fatigue crack growth rate evaluation. Implementing the standardized test specimen may complement the creation of new techniques to avoid weld stress relaxation of the critical welded high strength steel structure for probabilistic fatigue crack growth rate evaluation.

Keywords: fatigue crack growth, high strength low-alloyed steel (HSLA), linear elastic fracture mechanics (LEFM), finite element method (FEM), residual stress