自行車模型驗證與響應預測

Model Verification and Response Prediction of Bicycle

陳昱成(YU-CHENG CHEN)

指導教授 ： 王栢村

國立屏東科技大學/工學院/機械工程系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00093

摘要

目前各自行車製造廠也逐漸將電腦輔助工程分析(Computer Aided Engineering, CAE)技術導入設計開發流程，為能提昇競爭，使開發時程亦持續縮短，便能在短時間完成複雜的設計工作，故本文主要針對一部城市車進行有限元素分析和實驗模態分析建立一系統化之自行車設計分析開發流程。本研究首先利用自行車結構組合層次堆疊概念之模型驗證進行理論有限元素分析，求得理論之模態參數，並以實驗模態分析方法求得實際結構之頻率響應函數，經由曲線嵌合軟體得到實際結構之模態參數，包括自然頻率、模態振型及阻尼比，藉此驗證後模型進行響應預測分析；參考歐盟EN14764城市與旅行自行車試驗規範之垂直力衝擊試驗試驗，透過預測結果判斷車架與前叉組合結構受力後變形量與應力強度是否符合規範；以及探討自行車行駛於半正弦波凸起路面之暫態響應分析，瞭解不同速度下座位和輪胎位移響應以及車架結構位移量與應力變化。進而來提高整車之安全性，並建立整合CAD/CAE/CAT之虛擬測試(virtual testing)技術於自行車設計開發分析與試驗，藉由此一系統化技術流程，能有助於提升國內自行車產業在製造技術與創新設計之能力。

關鍵字

有限元素分析 ； 實驗模態分析 ； 模型驗證 ； 響應預測 ； 歐盟EN14764規範

並列摘要

Computer aided engineering (CAE) technique has been adapted to product design for increasing industry competitive ability and reducing development efforts. This work integrates both finite element analysis (FEA) and experimental modal analysis (EMA) techniques to perform model verification of bicycle components for product design analysis. The step-by-step model verification of the frame, front fork, and the frame and front fork assembly for the substructures of bicycle is conducted. The FEA is first performed to obtain natural frequencies and mode shapes of the bicycle. The EMA is then carried out for the bicycle to determine structural natural frequencies, modal damping ratios and mode shapes. By the comparison of modal parameters obtained from FEA and EMA, the structural material constants can be updated to get the equivalent FE modal via modal verification process. The EN14764 standard for the vertical impact test of city trekking bicycles is considered. The validated FE model of the frame and front fork assembly structure can then be applied to predict the structural deformation and stress distributions. The transient response analysis of the bicycle running on the half-sine bump is also presented to determine the seat and tire displacement response as well as the frame structural stresses for different bicycle speeds. The integrated CAD/CAE/CAT for virtual testing technique is applied to bicycle components and product design analysis. This work establishes the procedure for design modification, especially for the pre-study of structural model verification and response prediction. The developed methodology can be useful for bicycle industry in manufacturing technology and innovative design analysis.

並列關鍵字

Finite Element Analysis(FEA) ； Experimental Modal Analysis (EMA) ； Model Verification ； Response Prediction ； EN 14764 standard

參考文獻

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