NiTi合金动态断裂过程的实验和数值方法研究

发布时间：2018-01-23 18:59

  本文关键词： 霍普金森杆 数值方法 NiTi合金 裂纹扩展计 动态断裂过程　出处：《中国测试》2016年10期 　论文类型：期刊论文

【摘要】：为获得Ni Ti合金的动态起裂韧度和动态扩展速度与动态加载率之间的定量变化规律。利用分离式霍普金森压杆(SHPB)测试系统对单边三点弯曲试样(SENB)进行冲击加载试验,采用实验-有限元相结合的方法,获得动态断裂参数随时间的变化规律。SENB试样裂纹起裂时刻和裂纹扩展速度由粘贴在裂纹尖端的裂纹扩展计(CPG)测定。采用上述方法和数据获得Ni Ti合金的I型动态起裂韧度和动态扩展速度。实验结果表明:裂纹扩展计测得的起裂时刻与粘贴在同一试样上的监裂应变片测得的结果基本相符,因此可以利用裂纹扩展计代替传统的监裂应变片来监测裂纹起裂时刻,并获得Ni Ti合金的起裂韧度。同时,可以利用裂纹扩展计(CPG)获得裂纹动态扩展过程,绘制出裂纹扩展速度与时间的关系曲线,从而探讨Ni Ti合金的动态断裂韧度和裂纹扩展速度与动态加载率之间的定量变化规律。
[Abstract]:In order to obtain the quantitative variation of dynamic crack initiation toughness, dynamic propagation velocity and dynamic loading rate of Ni Ti alloy, the split Hopkinson compression bar SHPBwas used. The impact loading test was carried out on the single-sided three-point bending specimen with a testing system. The method of combining experiment with finite element method is adopted. The variation of dynamic fracture parameters with time is obtained. The crack initiation time and crack growth velocity of SENB specimen are measured by the crack propagating meter (CPG) which is affixed to the crack tip. Measurement. I dynamic initiation toughness and dynamic propagation rate of Ni Ti alloy were obtained by using the above method and data. The experimental results show that:. The crack initiation time measured by crack propagation is basically consistent with that measured by the strain gauge attached to the same specimen. Therefore, the crack initiation time can be monitored by using crack propagator instead of the traditional crack monitoring strain gauge, and the fracture initiation toughness of Ni Ti alloy can be obtained. At the same time, the crack initiation toughness of Ni Ti alloy can be obtained. The crack dynamic growth process can be obtained by using the crack Propagation Meter (CPG), and the curve of the relationship between the crack growth speed and the time can be drawn. The quantitative variation of dynamic fracture toughness, crack growth rate and dynamic loading rate of Ni Ti alloy is discussed.
【作者单位】： 四川大学建筑与环境学院;
【基金】：国家自然科学委员会与中国工程物理研究院联合基金项目(U1430119)
【分类号】：O346.1
【正文快照】： 0引言Ni Ti形状记忆合金以其独特的超弹性、形状记忆性能及良好的生物相容性而备受关注,目前已广泛应用于医疗外科、薄膜、航空和微机电等领域[1]。由于形状记忆合金在工程领域的特殊性,其工作环境较为恶劣,常遭受碰撞、挤压等动态荷载。尤其在航空航天领域,形状记忆合金构件，

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