Analysis of Mechanical Properties of Welded Joints Based on Mises Yield Criterion and I₁ Fracture Criterion

The Mises equivalent stress σ and the first stress invariant I1 were derived by considering the welding residual stress, loading stress and hydrogen induced stress; The influence of residual stress and hydrogen stress on yield behavior is analyzed theoretically, and the expression of apparent yield stress σ_s under unidirectional stress is derived; The influence of residual stress and hydrogen stress on fracture behavior is analyzed theoretically, and the expression of apparent fracture stress I_b under unidirectional stress state and the expression of eigenvalue I^s₁ under apparent yield state are derived.