用于J阻力曲线测试的载荷分离直接标定法

发布时间：2018-01-09 03:13

本文关键词：用于J阻力曲线测试的载荷分离直接标定法　出处：《航空学报》2017年10期 　论文类型：期刊论文

【摘要】：基于载荷分离原理提出了确定不同裂纹长度钝裂纹紧凑拉伸(CT)试样的载荷-位移(P-V)曲线显式表达式的方法,进而通过与尖裂纹试样的P-V曲线进行对比分析,发展了直接确定尖裂纹试样实时裂纹长度的载荷分离直接标定(LSDC)法。该方法无需在试样断面上进行任何裂纹长度的物理测量。采用Cr2Ni2MoV钢制成的CT试样验证了LSDC法的可行性和有效性。研究结果表明,LSDC法得到的J阻力曲线相比柔度法和规则化法更加合理、精确。由LSDC法还可从相同初始裂纹长度条件下的钝裂纹和尖裂纹CT试样的P-V曲线分离点得到能够真实反映材料启裂的临界断裂韧度,相比根据0.2mm钝化偏置线交点确定的传统条件启裂韧度值更为合理,且具有更小的数据分散性。
[Abstract]:Based on the principle of load separation, a method for determining the explicit expression of load-displacement P-V curves for compact tensile CTs with different crack lengths is presented. Then the P-V curve of the specimen with tip crack was compared and analyzed. The direct calibration of load separation for determining the real time crack length of tip crack specimen has been developed. The method does not need any physical measurement of crack length on the cross section of the specimen. The feasibility and validity of the LSDC method are verified by the CT specimen made of Cr2Ni2MoV steel. The results show that the method is feasible and effective. The J resistance curve obtained by LSDC method is more reasonable than compliance method and regularization method. The LSDC method can also be used to obtain the critical fracture toughness from the P-V curve separation points of the CT specimens with blunt crack and tip crack at the same initial crack length. Compared with the traditional condition based on the intersection point of 0.2mm passivated bias line, the crack initiation toughness is more reasonable and has less data dispersion.
【作者单位】：西南交通大学力学与工程学院;
【基金】：国家自然科学基金(11472228)~~
【分类号】：O346.1;V215.6
【正文快照】： 网络出版地址:http://hkxb.buaa.edu.cn/CN/html/20171016.html引用格式:巫元俊,包陈,何广伟,等.用于J阻力曲线测试的载荷分离直接标定法[J].航空学报,2017,38(10):221128.WU Y J,BAO C,HE G W,et al.Load separation based direct calibration method for estimating J-resis

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