1. School of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan, Shanxi, P. R. China;
2. College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, P. R. China;
3. Shanxi Provincial Key Laboratory of Metallurgical Device Design Theory and Technology, Taiyuan University of Science and Technology, Taiyuan, Shanxi, P. R. China;
4. Heavy Machinery Engineering Research Center of the Ministry Education, Taiyuan University of Science and Technology, Taiyuan, Shanxi, P. R. China