Finite Element Analysis for Impact Test of Aluminum Rim

基於安全的考量與法規的要求，輪圈的結構強度需通過一連串的測試，然而在開發成品過程中，將耗費相當多的時間與成本，為了減少時間與成本，通常會採用電腦輔助工程分析(Computer-Aided Engineering，CAE)技術從事輪圈的設計。 本論文主要研究輪圈衝擊實測之CAE模擬分析，利用有限元素法軟體LS-DYNA從事動態模擬分析、ABAQUS/Standard從事靜態模擬分析，探討輪圈受重錘撞擊時的破壞行為。 在模型建立方面，針對輪圈13度與90度的邊界條件提出說明。此外，亦對線性四面體元素及二階四面體元素進行收斂性分析，指出可行之元素大小及元素種類。 在模擬分析方面，比較不同等效動態負載模式，並且發現以能量法修正的等效負載最能符合動態模擬的結果。此外，針對彈性與彈塑性材料之間，以應變能密度之觀念來訂定其破壞準則。 最後利用所建立之有限元素模型，與輪圈實測撞擊分析之結果比對。本論文之研究成果可提供輪圈實測模擬分析之參考。For the safety sake and for the regulation requirements, the structural strength of rims has to be examined via a series of tests. However, it is time consuming and expense costly in the development of a product to pass the tests. In order to save time and cost, the CAE (Computer-Aided Engineering) technology is usually adopted to design rims.his thesis aims to investigate the CAE technology for the strength analysis of aluminum rims. The CAE simulation models were developed to calculate the rim strength using the dynamic/explicit finite eminent code LS-DYNA and the static finite element code ABAQUS/Standard, for the dynamic and static analyses, respectively. The CAE models were constructed to simulate the 13 degree and 90 degree rim impact tests. The dynamic analysis was preformed first to evaluate the validity of the boundary conditions imposed in the CAE models. The load data and strains in the deformed rims were measured in the actual tests and the validity of the CAE models was confirmed. The boundary conditions were then converted to an equivalent load condition for the static analysis using various approaches. In addition, a failure criterion was also established form both the actual tests and the dynamic CAE simulations.n equivalent failure prediction mode was developed as well in the present study for the static stress analysis for the rim impact test. In the equivalent mode, the failure of the rim in the impact test can be predicted by using the elastic static analysis. The developed equivalent failure mode was validated by the actual impact tests and can be used in the rim design.目錄 I目錄 III目錄 V一章 緒論 1.1 前言 1.2 研究動機與目的 2.3 文獻回顧 4.4 研究方法與步驟 7.5 論文總覽 10二章 研究載具介紹及破壞模式 11.1 研究載具介紹 11.2 有限元素模擬軟體簡介 13.3 顯性積分法 16.4 網格系統之建立 19.5 輪圈撞擊試驗常見之破壞形式 22三章 有限元素模型之建立 26.1 鋁輪圈模型之材料性質 26.2 元素收斂性分析 29.3 十三度衝擊CAE模型之建立方式 35.3.1 ABAQUS/standard靜態十三度模型介紹 36.3.2 LS-DYNA動態十三度模型介紹 39.4 九十度衝擊CAE模型之建立方式 44.4.1 ABAQUS/standard靜態九十度模型介紹 46.4.2 LS-DYNA動態九十度模型介紹 48四章 輪圈破壞之判定準則 52.1 動態與靜態模擬比對 53.2 等效靜態負載 55.2.1 動態最大衝擊受力法 55.2.2 動量守恆求得接觸力 58.2.3 能量法公式 61.2.4 三種等效負載之適用性討論 70.3 彈性與彈塑性材料等效原則 72五章 輪圈衝擊實測驗證 78.1 輪圈衝擊試驗 78.1.1 實驗項目 78.1.2 實驗原理 79.1.3 實驗儀器 80.1.4 實驗測試方法規劃 80.2 試驗結果討論及模擬比對 83.3 輪圈破壞準則實例 93六章 結論 96.1 研究結論 96.2 建議 97考文獻 9