Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 11, 2022 - September 14, 2022
In hitting sports, the coefficient of restitution (COR) is one of the most important items in evaluating the performance of hitting. Many previous studies have shown that the COR has the relation to the natural vibrations of the impacting body and impacted body. However, it is still not clarified in the treatment of boundary condition for the calculation of natural frequencies, and the use of evaluation model. In this study, we created the models of an impacting body and an impacted body with simple 3D FEM models. By changing the shape of the impacting body consecutively, we investigated numerically the relationship between the natural frequencies and COR. The correlation of each eigenmode to the deformation of impacting body during impact was calculated and used to evaluate the contribution of the eigenmode to the COR. From the analysis results, we found that: 1) in the case of a dominant eigenmode existing at the impact, COR can reach to a peak value by adjusting the natural frequency of the impact body to that of the impacted body; 2) in the case of no dominant eigenmode existing, multiple eigenmodes have the contribution to the COR.
