Interval Fatigue Life Prediction of Dissimilar Metal Cruciform Welded Joints under Impact Loading

Abstract

In order to characterize the local damage and fatigue strength of 5754 and 5052 aluminum alloy cross-welded joints containing pre-cracks under impact loading, an interval fatigue life prediction approach is presented based on the continuum damage mechanics and the uncertain interval analysis technique. The impact test is carried out on the cruciform welded joints of dissimilar lightweight metals with U-type pre-crack located at the middle edge of specimen. In consideration of uncertain factors caused by the welding process, the interval fatigue damage model under the coupling effect of fatigue and impact load is established. Then, the interval fatigue parameters and interval curve between stress amplitudes and fatigue life are determined. The impact process is simulated by using the finite element dynamic analysis to obtain the stress and plastic strain fields. Based on the suggested model, the predicted results agree well with the experimental data.

Keywords

• continuum damage mechanics
• fatigue life
• impact
• interval approach
• welded joints