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Abstract:In
order to discuss the effect of tensile specimen section shape on void
damage of metal materials, notch tensile tests and pre-tensile impact
crack tests under low temperature are conducted on specimens with round,
rectangular section. Fracture surface of SEM is observed. Finite element
method is used to simulate the elasto-plastic deformation of the
specimens. The distribution of void damage rates along fracture surface
, the situation of fracture origin and void growth around the situation
of fracture origin are simulated by using mecromechanical model. Results
show that section shape of notch specimens have significant influence on
void evolution, There exists noticeable difference in void damage rates
along fracture surface between round and rectangular section, which
means that critical void damage rates is not material constant. There is
more error in simulating void growth under unaxisymmetry triaxial stress
conditions using R-T model and GTN model.
Key words: Plastic
strain Void Cell model Stress triaxiality
CLC No: O344
国家自然科学基金(19972055)和航空科学基金资助项目(00C53022). Received 20010307, received in
revised form 20011026 |