摘要
利用Hopkinson压杆测量三点弯曲试样材料的动态应力强度因子,应力波载荷的惯性效应和弥散效应对试验结果不可忽略的影响已被许多学者的实验结果证实。将不同Hopkinson压杆入射杆形状产生的载荷—时间历程曲线作为动态有限元模型的载荷信息,采用Ansys/LS-DYNA有限元软件,基于虚拟裂纹闭合技术(virtual crack closure technique,VCCT)计算得到三点弯曲试样的动态应力强度因子变化曲线,曲线上起裂时间对应的值即为材料的动态断裂韧度。进一步考虑入射杆形状及惯性效应对冲击载荷曲线的影响,研究动态应力强度因子的变化规律,为Hopkinson压杆测试动态断裂韧度提供合理、可行的方法。
A number of experimental results presented by many scholars confirmed that the effect of inertia and dispersion of stress wave can not be neglected in the dynamic stress intensity factor test of the three-point bending specimen loaded by Hopkinson pressure bar.The commercial finite element method （FEM） software Ansys/LS-DYNA with the virtual crack closure technique （VCCT） is employed to calculate the dynamic stress intensity factor history curve of the specimen,which take the load-time history obtained by Hopkinson bars as input data,and the value of the dynamic stress intensity factor on spot of the crack initiation time is the dynamic fracture toughness.Considering the effect of different shape of the incident bars,the variety of dynamic stress intensity factor is studied,and it also offered a reasonable method to test the dynamic stress toughness by Hopkinson pressure bar loaded tests.
出处
《机械强度》
CAS
CSCD
北大核心
2011年第1期120-125,共6页
Journal of Mechanical Strength
基金
国家自然科学基金资助项目(10776023)~~
