The Experimental And Numerical Simulation Research On Tension-Shear Failure Of Notched Specimen Of Ductile Material

This paper takes the T2 copper of ductile materials as the research object. The various notched round specimens and plate shear specimens are taken to tension and shear tests, and notched hollow round specimens are applied to torsional experiments.The experiments using various specimens from beginning loading to the deformation and to the final destruction of the entire process are recorded. Part of the specimens are stopped at specified load positions, and the specimens are processed by line cutting along the longitudinal symmetry plane, by grinding and polishing machine to achieve required smoothness. And then the samples are observed, the position of crack initiation and crack expansion trend are investigated through a 3D microscope system. The observations can be used to study the material failure under complex stress state, and can be analyzed by numerical simulation.On the experimental basis, the data of uniaxial tensile, shear and torsion tests are processed, and then the numerical simulation by finite element software ABAQUS/Standard is carried on. Stress distributions on ligament cross section of various specimens are further analyzed through FEM simulations. Then the results are compared with the tests, and the stress triaxiality, lode parameter and equivalent strain are studied with respect to their influence on material failure.This investigation find that:(1) For different notch radius of round bar, with the gap radius decreasing, specimen fracture initiation position transits from the center to edge of the specimen ligament, which mainly depends on the influence of stress triaxiality due to which increases with notched radius decreasing, and the fracture strain decrease with the transition. (2) According to all tests of this paper and numerical analyses, it is concluded the law of the stress triaxiality, Lode parameter and equivalent strain influence on the material failure.