Fatigue Life Prediction Incorporating Constraint for the Thin-walled Dissimilar High-energy Beam-welded Structure Interface Region

To accurately predict fatigue life in the interface region of thin-walled Dissimilar Metal High-energy Beam-welded Structures (DMHEBWS) of reusable space vehicle components, a fatigue life prediction method incorporating constraints is proposed. The method modifies the linear elasticity fracture toughness, (KIC) crack expansion rate (d a/dN), and critical crack size (a c) of the traditional fatigue life prediction method based on constraint theory. The constraint-related fatigue life surface of the 1050A/5A06 DMHEBWS interface region and its calculation formula were established, and fatigue life prediction and experimental verification were carried out for a certain crack in this interface region. Experimental results show that compared with traditional fatigue life prediction methods, the method incorporating constraints is more accurate.