Ti-6Al-4V中温应力松弛行为建模及模拟研究（英文）

发布时间：2018-03-11 13:15

本文选题：Ti-Al-V　切入点：应力松弛　出处：《稀有金属材料与工程》2015年05期 　论文类型：期刊论文

【摘要】：应力松弛是钛合金在升高温度和加载条件下的一个显著特性,也是热校形和热处理的理论基础。因此研究了一种Ti-6Al-4V钛板在923~1023 K温度范围内、几种应变水平下的拉伸应力松弛行为。结果表明,应力松弛速率随着温度的升高而增加,材料中的残余应力经过一段时间之后趋向应力松弛极限;另外,在相同温度下,不同应力水平的应力松弛极限相同。进而,建立了一种描述应力松弛行为的显式三次延迟函数,本构精度高达97%,可用于工艺设计及理论分析。最后,基于应力松弛和蠕变的关系,提出了一种隐式蠕变型本构方程描述应力松弛行为,并将识别的材料参数输入ABAQUS,数值模拟了Ti-6Al-4V的热应力松弛行为,发现模拟的应力变化规律符合应力松弛曲线,证明了蠕变型本构方程对应力松弛模拟的适用性。
[Abstract]:Stress relaxation is a remarkable characteristic of titanium alloy under elevated temperature and loading conditions, and is also the theoretical basis of thermal alignment and heat treatment. Therefore, a kind of Ti-6Al-4V titanium plate is studied in the temperature range of 923 ~ 1023K. Tensile stress relaxation behavior at several strain levels. The results show that the stress relaxation rate increases with the increase of temperature, and the residual stress in the material tends to the stress relaxation limit after a period of time; in addition, at the same temperature, The stress relaxation limit of different stress levels is the same. Furthermore, an explicit cubic delay function describing stress relaxation behavior is established. The constitutive accuracy is as high as 97. It can be used in process design and theoretical analysis. Based on the relationship between stress relaxation and creep, an implicit creep constitutive equation is proposed to describe the stress relaxation behavior. The identified material parameters are input into Abaqus, and the thermal stress relaxation behavior of Ti-6Al-4V is numerically simulated. It is found that the stress variation of the simulation accords with the stress relaxation curve, which proves the applicability of the creep constitutive equation to the stress relaxation simulation.
【作者单位】：北京印刷学院;北京航空航天大学;
【基金】：National Natural Science Foundation of China(51175022) National Defense Pre-research Program of China(51318040315)
【分类号】：TG115.5;TG146.23

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