Abstract: In order to study the effect of torsion precision on pre-setting process， the elastic-plastic theory was used to discuss the pre-setting process of torsion bar spring. Then， a mathematical model changing with stress， torque and residual stress was obtained under yield pre-setting and plasticity pre-setting situation. The ABAQUS software was used to simulate torsion bar spring with different models and pre-setting situations， and the effect of pre-setting precision on torsion bar spring was analyzed. The results showed that the effect of torsion bar spring pre-setting process in the range of torsion error on pre-setting is less than 5%. The test data not only validates correctness of the finite element model， but shows that torsion bar spring with no more than ±1° pre-setting error can be seen approximately equivalent. The results provide a theoretical reference for improving the process of torsion bar spring pre-setting.

Key words: torsion bar spring, elastic-plastic, pre-setting process, numerical simulation, pre-setting test