- 學位論文
車輛油箱之結構分析與耐久性評估
Vehicle fuel tank structure analysis and durability assessment
摘要
本論文首先應用PRO-E繪圖軟體繪出一給定的鐵製汽車油箱，然後以ANSYS有限元素分析軟體提供的APDL語言撰寫巨集程式，考量包含標準入力條件、車輛操作入力條件、油箱液振效應等不同情況下之負載與適當的邊界條件，進行該油箱之力學分析，再以分析所得的結果代入Palmgren-Miner疲勞累積損傷法則，以評估油箱之累積疲勞損傷及其壽命。此外，本論文也採用可靠度工程中常用之失效模式、影響與關鍵性分析(Failure Mode, Effect and Criticality Analysis, FMECA)，來判斷油箱之可能失效原因，以補耐久性評估之不足。本研究結果顯示當油箱受到內部油氣之正負壓力影響時，其對油箱整體的疲勞壽命影響最大，因此透過本論文可知油箱最關鍵性的失效成因即為油氣產生正負壓之影響。
並列摘要
The thesis focuses on the analysis of a vehicle fuel tank. First, within the general CAD (Computer Aided Design) area, PRO-E software is employed to draw the configuration of the fuel tank to be analyzed. Secondly, within the content of CAE (Computer Aided Engineering) and through appropriate definitions of loading and boundary conditions, a macro program for static analyses of the tank is developed utilizing Automatic Parametric Design Language (APDL) provided by ANSYS. Thirdly, failure mode, effect and criticality analysis (FMECA) and fault tree analysis (FTA) are used to identify possible failure modes of the fuel system and its subsystems. The purpose of the above work is to find key components that are vulnerable to failure, and to find the maximum stress and strain as well as expected life and damage of the fuel tank. This result of study shows when the fuel tank is influenced by the shouldering the pressure of inside oil gas, it exerts a largest influence on whole fatigue life of fuel tank.