硅锰合金扭簧应力松弛行为研究

研制了矩形截面扭簧应力松弛试验装置并进行了多组高温实验；提出了可动位错密度函数，结合现有应力松弛位错理论提出了新的硅锰合金弹簧钢扭转应力松弛动力学方程；利用ABAQUS二次开发接口CREEP子程序，实现了将新的应力松弛动力学方程转化为基于隐式有限元法的修正时间硬化蠕变模型，对400℃下的硅锰合金弹簧钢扭转应力松弛行为进行了数值模拟；模拟结果表明，修正的时间硬化蠕变模型与试验结果吻合，扭簧表面的Von Mises应力随时间变化规律与试验中的扭矩随时间变化规律一致。

Research on stress-relaxation behavior of silicon-manganese alloy torsion-spring

The stress-relaxation test device is designed for rectangular section torsion spring and more group high-temperature tests are completed. The movable dislocation density function is proposed, and combined with the existing stress-relaxation dislocation theory, a new stress-relaxation kinetic equation is proposed for silicon-manganese alloy spring-steel. By using CREEP subroutine, ABAQUS secondary development interface, the new stress-relaxation kinetic equation is converted to a modified time hardening creep model based on implicit finite element method. Meanwhile, the torsion stress-relaxation behavior of silicon-manganese alloy spring-steel under 400°C is numerically simulated by using the new model. The simulating results showed that the stress-relaxation model is identical with the test results. The law of Von Mises stress on the surface of torsion-spring varying with time is consistent with that of the torque in the experiments.