摘要
针对实心圆轴拉、扭组合实验全寿命过程中拉(σ)、扭(τ)应力按固定比例加载的难题,基于拉扭试验机控制的核心问题,从弹性应力比C(σ/τ)的概念出发,推导出载荷比F/T(轴力/扭矩)控制参数,同时考虑全寿命中的拉扭真应力关系,给出载荷程序控制路线,应用PID方式实现试验机控制。以304不锈钢及16MnR碳钢为研究对象,进行了24组不同C的拉扭实验。在此基础上,以塑性过程中的真应力比槇C(σ/τ)为依据,提出了比例修正系数C'的概念,解决了试验机在全过程的控制问题。结果表明:以C为基础的控制模式可对弹性阶段精确控制;材料进入塑性后,C的差异与材料无关,仅与控制方法有关;将提出的C引入控制程序后,可有效提高全寿命过程中应力按比例加载的准确性。
To investigate how to realize the fixed proportional tension-torsion loading test in the life cycle of solid cylindrical shaft,the route of loading control is based on the theory of elastic stress ratio[C（ σ / τ） ]with the consideration of true stress and strain,the PID control method is used in the tension-torsional testing machine. 24 series of experiment has been done in different C with 24 specimens of 16 MnR and 304 stainless steel. A ratio correction coefficient（ C＇） is put forward depend on the true stress strain ratio C（ σ / τ） and experiment results. The results show that： the control route based on C is accurate when the specimen in elastic phase. The difference of C between 16 MnR and 304 SS is related to control method,but not related to specimen when the material gets to large plastic deformation. The accuracy of the fixed proportional tension-torsion loading test in the life cycle was increased when the C＇is applied to control procedure.
出处
《科学技术与工程》
北大核心
2015年第29期1-6,共6页
Science Technology and Engineering
基金
国家科技支撑计划(2011BAK06B02)资助
