Simulation of Ductile Fracture of Circular Hollow Section Joints Using the Gurson Model

Abstract

Numerical modeling of the fracture effects on the strength of steel circular hollow section joints has not been sufficiently addressed historically. The Gurson model simulates the plastic yield behavior of material with microvoids. It is found in the current study that we can offer an alternative approach in modeling the ductile fracture for the strength analysis of tubular joints. Two loading conditions are investigated on tubular bars with the Gurson model. The effects of void growth and nucleation are observed to be more prominent in the axial tensile mode than the shear mode. Two types of tubular joints are investigated: precracked tubular joints and intact tubular joints. The effect of ductile fracture is reflected by softening of material, which leads to reductions in load-deformation curves which are consistent with test observations. Due to the lack of material data, a sensitivity study is carried out on the Gurson's material properties.