THE SIMULATION OF MECHANICAL STIMULATION EFFECT ON BONE ELASTICITY LIMIT BASED ON FINITE ELEMENT METHOD (FEM)

Osteoporosis is a disease  affecting bones which is characterized by decreased bone density;  bones become porous and  susceptible to fractures. Osteoporosis occurs because of an imbalance during bone remodeling phase between resorption and formation processes. This study aims to simulate the effects of mechanical stimulations on the femoral bone elasticity limit. It is hoped that these mechanical stimuli can provide information on bone elasticity limits. Initially, we constructed the femur in two layers using triangular elements. Then we entered the bone properties (Young’s modulus and Poisson’s ratio) based on the age of the femur. After that we  calculated the value of the stress, strain, and strain rate in the reversal phase. Next, we calculated the  bone density using the thermodynamic equation and calculation of the bone elasticity limit using particle swarm optimization (PSO) methods. The value of stress and strain caused by walking is higher than the value of stress and strain when standing still. In this case, the difference in activity results an increase in stress by 33.82% and an increase in strain and strain rate by 34.57%. Based on these simulation results, it can be concluded that mechanical stimulation can increase the limit of bone elasticity to 2.99% in cortical bone and 0.975% in trabecular bone. Bone elasticity limit can be used to determine the level of osteoporosis that occurs. The higher value of the bone elasticity, the smaller the possibility of osteoporosis.