基于SENT试样获取材料断裂韧度的载荷分离法研究  

Study on the Load Separation Method of SENT Specimens for Fracture Toughness Assessment

作　　者：姚瑶[1] 蔡力勋[1] 包陈[1] 石凯凯[1] 

机构地区：[1]西南交通大学力学与工程学院,成都610031

出　　处：《机械工程学报》2014年第10期48-57,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(11072205)

摘　　要：单边裂纹拉伸(Single edged notched tension,SENT)试样因其低约束特性逐渐被用于管道材料的断裂韧度评定。根据有限元法,提出SENT试样的应力强度因子表达式,J积分计算中的增量塑性功算式以及塑性因子算式,并与文献中公式进行对比证实公式的精确性和有效性。依据ASTM用于CT试样获取断裂韧度载荷分离理论规则化方法提出适用于SENT试样的量纲一载荷分离法,并通过有限元计算证实SENT试样载荷分离的成立性。由量纲一载荷分离理论中的规则化方法完成了汽轮机低压转子材料30Cr2Ni4MoV、电站用P92管道钢以及5083-H112铝合金SENT试样断裂韧度值以及J阻力曲线测定,获得了各材料合理的J阻力曲线及条件断裂韧度JQ值。In view of low constraint properties,single edged notched tension（SENT） specimens are gradually applied for the assessment on fracture toughness of pipe materials.Detailed analyses for the stress intensity factor,incremental plastic work and plastic factor used in the J-integral computation are conducted.The precision and validity are confirmed through the comparison between formulas obtained and references.Systematic investigation on the estimation of J resistance curves for SENT specimens is carried out on the basis of normalization method which concludes in the non-dimensional load separation method.The establishment of the load separation for SENT specimen is verified by finite element analysis.30Cr2Ni4MoV used for steam turbine low pressure rotors,T92 pipe steel and 5083-H112 aluminum alloy are employed to experimentally complete the estimation of J resistance curves of SENT specimens by using the normalization method of non-dimensional load separation and reasonable fracture toughness values are acquired.

关 键 词：断裂韧度 J阻力曲线 单边裂纹拉伸试样 量纲一载荷分离 规则化法 

分 类 号：TV313[水利工程—水工结构工程] O346[理学—固体力学]