Modeling And Dynamic Analysis Of Human Body & Trampoline Motion System

Trampoline is a technical sport, originated in the medieval acrobatic performances. In 2000 Sydney Olympics Games, trampoline first was accepted as an Olympic event. In 1998, trampoline was official launched as a sport game in China. After 10 years of development, trampoline athletes have made excellent achievements, and trampoline has become China’s superiority project in the Olympic Games. The aim to establish 3D human body&trampoline system is to simulate the movements of the athlete. The simulation results are synchronized with the athletes training video, so the coaches can train the athletes more vividly. At the same time a scientific training system theory is established, which provides guidance for understanding the human body & trampoline system jumping and improving the performance of athletes. At last athletes’s stress of joints and muscles can be known detailly, which is important to prevent athletes form injury. This thesis is to build up a 3D simulation system for human body & trampoline. Fist trampoline model is built, and then the mechanical test was made on the trampoline model. Secondly experiments were carried out to study the contact force of foot and net. Finally athletes’s moving track was analyzed by the video analysis software, so as to establish the 3D human body & trampoline system by the biological software LifeMOD. The follows are the work and main results of this thesis.1. The trampoline ADAMS model was established, which could simulate the mechanical characteristics of net center area. Different from other sports events is that the indicators of trampoline equipment is uncertain. Both the USA national standards (ASTM F381-14) or UK national Standards (BS EN 13219:2008) are only prescribed the trampoline frame size, mesh size, spring the number of dimensions and so on. However, there are no rules for the mechanical characteristics of the central area of the trampoline net. In this paper the static loading experiments were taken on the trampoline net center area, to get the mathematics law of load and center net displacement. And then model of trampoline was established through the ADAMS software. The results shows that the model can accurately simulate the mathematics law of load and center net displacement, which can lay a foundation for establishment of human body & trampoline system.2. Two trampoline athletes’s contact force of foot and trampoline net was measured and analyzed during the jumping.In this paper two trampoline athletes in Jiangsu Province was studied as the research objects. Athletes’s contact force of foot and trampoline net was measured by wearing the foot pressure insole. The experiments show that maximum plantar dynamic stress is about 4-5 times of its static stress, when the jumping height is about 20 centimeter. At the same time, pressure of the foot heel is about 50% that of the whole foot. Therefore athletes and coaches should pay attention to the heel stress prevent fractures and sprains in trampoline competitions and training.3. The athletes’s jump process data was acqured, who participated in "Guangyuan Construction Cup" national Trampoline Championship. The jumping height of athletes was analyzed. And the jumping data of Dongdong was collected. Firstly trampoline players’s image data was recorded using high speed camera. Secondly the height of the athlete jumping was analyzed by the software Ariel. At last, the highest jump process of Dongdong was identified, so as to describe the trajectory of Dongdong.4. The dynamic model of 3D human body & trampoline system was established, which could simulate motion trajectory of Dongdong. And Dongdong’s joint and muscle force was analyzed in the jumping process. First, the human body of Dongdong was built by the software LifeMOD. And then imported the trampoline model and motion trajectory data. Dongdong’s dynamic and kinematics data was acquired, after inverse dynamics analysis and forward dynamics analysis of human body & trampoline model. The results show that the knee joint suffers the maximum force in the joints and the soleus muscles suffer the maximum tension in the leg, during the jumping process.