Dynamic modeling for the second flight phase of the Yurchenko layout vault based on MSC. ADAMS


The respected Comrade Kim Jong Un said as follows:

‟We should make great efforts to develop new branches of cross-disciplinary sciences in line with the trend of the comprehensive development of science and technology and the demands of socio-economic development."

The simulation of human movement is one of simulation technology that treats the study of human mechanical movement by using equivalent mechanical models, not his real movements. From these simulations, we can find sufficient muscle forces to perform a certain movement, build optimized movement strategy and predict joint reaction forces, so this technology is widely studied as a cross-disciplinary subject in sports and medical sciences. The faculty of Mechanics of Kim Il Sung University has made a series of achievements in the researches to simulate human movements by using multibody dynamics methods, and applied it to develop new performances of athletes.

The second flight phase of the vault is closely connected to difficulty value of gymnast's performance, and it is related to various mechanical initial conditions and gymnast's body configuration during flight. Furthermore, the Yurchenko layout vaults contain the rotations around the transversal and longitudinal body axes, so the 3D simulation models are needed to simulate this kind of movements.

To do this, we measured geometric parameters of a gymnast, and built his multibody dynamics model which contained 15 segments and 14 joints. Also, using nonlinear least square method, the joint angles were determined from his video data. And, we built a exclusive simulation interface of the second flight phase which can easily change initial conditions and joint angle trajectories by using ADAMS customized dialog builder. The inputted initial conditions were vertical and horizontal velocities and angular velocities around the transversal and longitudinal body axes. Then, we analysed the changes of initial conditions which affect a gymnast's vaulting performance such as touchdown somersault and twist angles.

From this results, we found a gymnast's appropriate body configurations and initial conditions to perform successfully his performance.

The result was published in the "Science of Gymnastics Journal"(12(2),2020) with the title "Dynamic modeling for the second flight phase of the Yurchenko layout vault based on MSC. ADAMS".