Numerical Investigations on the Fatigue Life of Lean Duplex Transverse Stiffeners in Bridges

Abstract

Numerical fatigue assessment of welded joints can be done using several approaches. The structural hot spot stress (SHSS) method based on finite element (FE) analysis is considered an effective approach when complex geometries or loading conditions exist. However, in the case of numerical evaluation of the SHSS, the results can differ significantly depending on the FE modelling parameters. In the present paper, the sensitivity of the SHSS to several of these parameters is investigated numerically on one selected critical fatigue-prone detail, namely a transverse weld attachment, in a stainless steel bridge. In parallel a static tensile test performed on the same welded stainless steel detail is presented to measure the SHSS. The strain field near the welded area is measured with digital image correlation (DIC). The experimentally measured and numerically computed SHSS as well as the deduced fatigue lives are then compared and the sources of discrepancy discussed.

Keywords

• stainless steel
• fatigue
• hot spot stress
• DIC
• FEM