复杂应力状态下典型材料全载荷过程中的力学行为

发布时间：2018-06-15 02:10

本文选题：复杂应力状态 + 全载荷过程　；参考：《应用基础与工程科学学报》2017年02期

【摘要】：针对材料在复杂应力状态下全载荷过程中的力学行为问题,应用实心圆轴试件进行拉扭联合试验,重点解决试验中拉伸扭转应力时时按固定比例C(σ/τ)加载的难题.以304不锈钢和16Mn R碳钢为研究对象,进行24组不同C值的拉扭试验.在此基础上,研究了实心圆轴试件在全寿命过程中等效真应力应变的处理方法,探索了不同应力状态对塑性极限承载能力的影响,并引入三轴应力度(TS)概念对其进行表征.结果表明:两种材料的极限应力(σ_(max))随着不同TS值变化均存在应力驻点,此处材料的σ_(max)最小;两种材料的极限应变(ε_(max))与TS值呈现反比函数关系;利用本文所提出的工程计算公式,可以在确定结构某点的应力状态情况下,推测结构在此时所能承受的极限应力与极限应变.但是不同材料的σ_(max)-TS、ε_(max)-TS呈现不同的函数关系,需分别进行试验标定.
[Abstract]:In order to solve the problem of mechanical behavior of materials under full load under complex stress state, the combined tensile and torsional tests are carried out by using solid circular axial specimens, and the problem that tensile torsional stress is always loaded at a fixed ratio C (蟽 / 蟿) in the test is solved. The tensile and torsion tests of 304 stainless steel and 16MnR carbon steel were carried out in 24 groups with different C values. On this basis, the treatment method of equivalent true stress and strain in the whole life of solid circular axial specimen is studied, and the influence of different stress states on plastic ultimate bearing capacity is explored, and the concept of triaxial force is introduced to characterize it. The results show that the limit stress of the two kinds of materials has the minimum stress stop point with different TS values, and the limit strain of the two materials is inversely proportional to the TS value, and the engineering calculation formula presented in this paper shows that the limit strain of the two materials is inversely proportional to the TS value, and that the limit strain of the two materials is inversely proportional to the TS value. Under the condition of determining the stress state of the structure at a certain point, the limit stress and the ultimate strain of the structure can be inferred at this time. However, 蟽 _ S _ max _ T _ S and 蔚 _ T _ (max-TS) of different materials show different functional relationships, and need to be calibrated separately.
【作者单位】：北京工业大学机械工程与应用电子技术学院;
【基金】：国家重点研发计划(2016YFC0801905-16)
【分类号】：TB301

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