Optimized Design and Analysis for Reducing Weight in Frame Structure of Treadmill

• Main Authors: Chun-Ting Chen, 陳俊廷
• Other Authors: Chih-Kuang Lin
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/cex47k

博士 === 國立中央大學 === 機械工程學系在職專班 === 106 === The aim of this study is to optimize the design for reducing weight of frame structure in a treadmill through finite element analysis (FEA) and experimental strain measurement. Firstly, FEA simulation and strain measurement are conducted for the original design to confirm the effectiveness of the FEA model. After that, Taguchi method and gray relational analysis are applied in a two-stage optimization process to determine the optimal combination of design parameters for reducing the frame weight without plastic deformation. Finally, based on the results of the second-stage optimization, a prototype frame is made to validate the FEM modeling in optimization process by performing an experimental strain measurement under maximum allowable load. The results show that after the two-stage optimization of design parameters, the frame weight of the treadmill is reduced from the original design of 68.7 kg to 60.2 kg, namely a decrease of 12.4%. The maximum von-Mises equivalent stress in the frame structure of new design is increased from 124 MPa to 203 MPa, which is an increase of 63.7% but does not exceed the yield stress (245 MPa). Therefore, no plastic deformation is predicted for the new design, indicating that the frame structure is safe. A prototype frame is made according to the optimized design parameters for comparing the FEA simulation with the experimental results. It reveals that the difference of stress at each selected measurement point is less than 11% between simulation and experimental result. It is thus confirmed that the FEA model developed for the two-stage optimization process is effective.