摘要
对霍普金森帽型试样动态剪切实验及其数据处理开展理论和有限元分析。利用分离式霍普金森压杆对TA2钛合金封闭平板帽型剪切试样进行实验验证,采用数字图像相关法直接测试加载过程试样剪切区的应变演化。结果表明:只要试样设计加载过程试样剪切区应力状态罗德参数μ_σ满足-0.46<μ_σ<0.46条件,即可当作剪切状态处理得到等效应力,其误差不超过3.4%;帽型剪切试样实验处理得到的等效应力-应变本构曲线与圆柱动态压缩本构实验结果符合较好,并且剪切曲线可反映出材料发生绝热剪切起始、扩展演化以及破坏的"软化"过程。
The stress states of shear zone for hat-shaped specimens loaded by split Hopkinson pressure bars are studied by theoretical analysis and numerical simulation.The shear test for the closed flat hatshaped specimens of TA2 titanium is carry out,and the shear strain is measured directly by the two-dimensional digital image correlation（DIC-2D） method.The results show that it can be used as state of pure shear only if the Lode parameters μ_σ meet the condition of -0.46 μ_σ 0.46 and the experimental data processing error is less than 3.4%.The dynamic constitutive curves obtained by shear testing are in agreement with the curves of cylindrical compression.The shear testing stress-strain curve softens once adiabatic shear bands（ASBs） form in the hat-shaped specimens,and the stress-strain curve reflects the initiation and evolution processes of ASBs.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2017年第12期2455-2462,共8页
Acta Armamentarii
基金
国家自然科学基金项目(11172144
11672143)
浙江省重点科技创新团队项目(2013TD21)
关键词
固体力学
帽型剪切试样
应力状态
动态本构特性
绝热剪切
数字图像相关法
solid mechanics
hat-shaped specimen
stress state
dynamic constitutive characteristic
adiabatic shear band
digital image correlation method
作者简介
周刚毅（1980-），男，博士研究生。E—mail：zhougangyi@nbu．edu．cn;董新龙（1964-），男，教授，博士生导师。E-mail：dongxinlong@nbu．edu．cn
