Abstract：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.
2014, Vol. 35 
