休旅車底盤結構剛性強度分析與轉向節輕量化設計

Structural Stiffness and Strength Analysis of the Chassis Structure and the Weight Reduction Design of the front Knuckle for a Sport Utility Vehicle (SUV)

張書源(ChangShuyuan)

指導教授 ： 胡惠文

國立屏東科技大學/工學院/車輛工程系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00230

摘要

本研究主要以電腦輔助工程設計分析方法進行休旅車底盤結構剛性強度分析與轉向節輕量化設計。透過三次元量測儀，量測出轉向節與下控制臂幾何特徵尺寸，經由電腦輔助設計軟體Unigraphics建構前懸底盤結構系統（CAD）模型，及使用電腦輔助分析軟體ANSYS建構底盤結構之有限元素分析（CAE）模型，並進行車體結構材料之機械性質測試，以提高電腦輔助分析模型的可靠性。在獲得等效懸吊系統分析模型上，採用應變量測及實驗模態分析達到模型驗證目地，再進行底盤結構強度與剛性分析。轉向節輕量化是採用鋁合金取代原始的鑄鐵材料，結構剛性與強度分析可以了解轉向節輕量化設計後對前懸吊系統是否影響整車操控性及乘客的舒適度及安全性。整車靜態實驗，包含整車重心量測、底盤零件重量分佈、應變量測；動態實驗包含跳動（Bumping）、過彎（Cornering）、煞車（Braking）測試，在不同行駛路況時，量測轉向節與避震器連接處、車身與避震器連接處及駕駛座位置，觀察不同車速及承載下對車輛避震系統振動衰減的情況，及懸吊系統轉向節在受力後應變的變化趨勢。

關鍵字

電腦輔助工程分析 ； 轉向節 ； 下控制臂 ； 輕量化設計 ； 鋁合金應變量測 ； 鑄鐵應變量測 ； 結構剛性與強度分析

並列摘要

This research presents the weight reduction design for a SUV knuckle and chassis structure analysis by using computer aided design and analysis technique. Mold tool is used to measure the 3D profile of knuckle and Control Arm. A computer-aided design software (UniGraphics) is used to rebuild a 3D detailed model. A commercial code, ANSYS, is used to establish a finite element model and analyze the strength and deformations of the chassis structure and knuckle. The mechanical properties are obtained from the tensile tests. The finite element model are validated in comparison with experimental modal analysis for knuckle and control arm. The weight reduction design for knuckle by using aluminum alloy A356-T6 is then investigated. A static test is conducted on the full vehicle to obtain the wheel loads, the center of gravity, the component weight and the strain of the knuckle. Dynamic test is conducted on the vehicle to measure the accelerations and the strain of the knuckle under the conditions of bumping, cornering and breaking. Test result are then used to validate the analysis result.

並列關鍵字

CAD/CAE ； Knuckle ； Control Arm ； weight reduction design ； Structure stiffness and strength ； dynamic test ； acceleration and strain.

參考文獻

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