Experimental study of the effect of macromechanical nonunifprmity on the fracture toughness of welding joints

摘要

Welded joint is a typical mechanical hctcrogeneous body. A quantity of welded structures service under dynamic loading condition. The study of dynamic fracture toughness of welded joint is of great importance both in theoretical and practical. A simplified welded joint model (softer material jointed to harder material ) is established by electronic beam welding technology in this paper. The effect of mechanical heterogeneity of welded joint on dynamic fracture toughness is investigated by using the established model. It is found that, the value of dynamic fracture toughness is lower when the crack located in the harder zone and the value incrcascs as the distance between the crack and the interface decreases, the value of dynamic fracture toughness is higher when the crack located in the softer zone and the value decreases as the distance belween the crack and the interface increases