電動機車車架設計與疲勞分析

本文主旨在於創新電動機車車架之輕量化設計，利用有限元素法模擬計算多種設計車架之剛性及強度，並從中挑出一部具高剛性、強度且較市面同級車架減重20%以上之設計車架，再針對該設計車架進行動態分析與疲勞壽命分析。在模擬部分，首先使用CAD軟體SolidWorks建立車架模型，再將車架模型匯入有限元素分析軟體ABAQUS中，進行車架剛性及靜態強度分析；接著應用機構模擬軟體ADAMS模擬車輛行駛於不同路面時之運動狀況，得到車架上各支點之負載歷程。再將此結果輸入ABAQUS作為負載條件，進行車架動態應力分析；並比較動態分析與靜態分析之結果與其差異性。由上述分析結果可預測車架上較容易損壞之區域，可作為日後改良時之參考依據。在疲勞分析部分，由ABAQUS分析之結果，匯出車架上熱點之應力歷程。由於此應力歷程為一不規則曲線，本研究利用雨流循環計數法計算出較具代表性之循環、振幅值與平均值。配合應力修正方程式和線性損傷累積法之理論，可有效計算車架之疲勞壽命。本研究利用FORTRAN程式將上述理論撰寫成一疲勞壽命分析之後處理模組程式。本文所發展之分析與設計方法，應可用於相關高剛性、疲勞強度之輕量化產品的設計開發。

關鍵字

機車車架設計；有限元素法；疲勞壽命分析；雨流計數法

並列摘要

The purpose of this thesis is to develop an innovative and lightweight vehicle frame for an electric scooter, which has high structural stiffness and strength. The solid model of the frame was first established by using the CAD software─SolidWorks while its stiffness and strength of the frame was analyzed by employing the finite element analysis software─ABAQUS. With the construction of the whole vehicle model and different road profiles, the loading histogram of the frame at locations of the suspension system was simulated by using the mechanism simulation software ADAMS. Then, by inputting the loading into ABAQUS model, the dynamic stress analysis was performed on the frame. Subsequently, the fatigue life of the frame was calculated from the rainflow counting method and the linear cumulative damage rule. The methodology developed in this study should be able to apply to other component design in the industry.

並列關鍵字

Design for an Electric Scooter ； Finite Element Method ； Fatigue Life Analysis ； Rainflow Counting Method

參考文獻

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[5] R. S. Sharp, "The Influence of Frame Flexibility on the Lateral Stability of Motorcycles," Journal of Mechanical Engineering Science, Vol.13, No.2,

pp.117-120, 1974.

國際替代計量

電動機車車架設計與疲勞分析

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