Effect of Triaxial Stress Constrain on Low Cycle Deformation Behavior for Polymer
A series of low cycle fatigue tests of polypropylene were carried out under stress-controlled mode on circumferentially notched bars with different notch radii to generate different triaxial stress fields. The effect of stress triaxiality and stress level on cycle deformation behavior had been studied. It was found the curves of that plastic strain range with cycle number contain softening stage that plastic strain range decreases with increase of cycle number and hardening stage that plastic strain range increase with increase of cycle number. The proportion of softening stage and hardening stage is dependent on stress triaxiality and stress level .Softening phenomenon occurs more easily at high stress triaxiality and high stress level than at low stress triaxiality and low stress level. There is only softening stage at a high stress triaxiality but high stress level. Hardening stage plays a key role at low stress triaxiality but low stress level, which is finally followed by a short softening stage. Softening stage plays a key role at low stress triaxiality but high stress level, which is accompanied a short hardening stage in initial several cycles.
polymer stress-controlled mode cyclesoftening cycle hardening stress triaxiality noncontacting video extensometer
WU Yanxia CHEN Weiyi CUI Dongliang
Department of Engineering Mechanics, Taiyuan University of Technology, Taiyuan, 030024,
国际会议
北京
英文
2007-08-05（万方平台首次上网日期，不代表论文的发表时间）