車門門飾板側突衝擊試驗之有限元素模擬分析

Finite Element Analysis for the Side Impact Test of an Automotive Door Trim System

吳昇穎(Sheng-Ying Wu)

指導教授 ： 陳復國

國立臺灣大學/工學院/機械工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201602285

摘要

汽車門飾板系統對於乘客的安全性有關鍵性的影響，因此必須通過一連串的實車門飾板側突衝擊試驗來檢測其安全性。然而實車門飾板側突衝擊試驗所需之成本較高且時程亦長，故目前在進行實際測試前，多會採用有限元素法模擬測試流程，來預測實車門飾板側突衝擊試驗的結果，以加速研發及優化設計等流程，減少所需成本的耗費。
為建立汽車門飾板側突衝擊試驗之有限元素法CAE模擬模型，本論文先進行塑膠材料拉伸試驗以取得載具材料聚丙烯之機械性質，並分別針對自載具雷射裁切試片與射出成型標準試片之拉伸試驗，研究其塑膠變形行為並探討何者有較佳之重現性且適用於CAE模擬分析模型。
本論文採用已開發車款之車門門飾板作為研究載具，利用簡化之汽車車門模型進行動態有限元素法分析，模擬衝擊塊撞擊車門門飾板之實車側突衝擊試驗過程及結果。在模型簡化之過程中，本論文探討必須考慮的要點，如結構體簡化、衝擊塊運動模式、搭接件間之連接方式及參數選用等，藉以建立車門門飾板側突衝擊試驗CAE分析模式，並探討車門門飾板系統參數對側突衝擊試驗結果與對衝擊試驗CAE分析效率之影響，以優化門飾板之側突衝擊性能以及縮短有限元素法分析之模擬時間。
本論文之研究成果可供未來設計人員進行車門門飾板系統研究之參考。

關鍵字

車門門飾板系統 ； 側突衝擊試驗 ； 塑膠材料拉伸試驗 ； 有限元素法分析 ； 模型簡化 ； 實驗驗證

並列摘要

Door trim system is a crucial factor determining a vehicle's safety. It is thus important to carry out series of practical door trim side impact tests to ensure the performance of a door trim system. However, time and cost are the main concerns on the design and test of a door trim system. Therefore the finite element method is often utilized to simulate the real door trim side impact tests before the actual examinations are carried out. The finite element simulations have been proven to be the most effective way to speed up the design and development relating to this field, in the same time minimizing costs.
This thesis took a door trim system mounted in a sedan as a carrier and conducted tensile tests to evaluate the mechanical materials properties of the carrier components which are made of polypropylene plastics. Two kinds of specimens were adopted to evaluate their deformation behavior, one kind was cut from the actual door trim by laser processing and the other kind is made from injection molding. The test results obtained from these two kinds of specimens were compared, and the reproducibility of the test results was examined. The material properties obtained by using the injection molding specimen showed a better reproducibility and were adopted for CAE simulations.

This thesis then investigated the deformation of the door trim being hit by the impactor in in the side impact test with the use of the finite element analysis. A simplified door trim system model was constructed to simulate the side impact test using the 3D dynamic/explicit code LS-DYNA. In the simplified model, the influences of model simplification, the movement of impactor, connecting condition for parts linkages and parameter selection are explored and evaluated. The simulation results were compared with those measured from the impact tests. The comparison shows that the load-displacement curves obtained by the finite element simulations agree to those measured from the experimental data with only an insignificant discrepancy. Finally, with the constructed CAE model, the optimum parameters for the door trim system were determined and the computation time for simulating the door trim side impact test was significantly saved.
The research results achieved in this thesis provide valuable references for the future design of door trim system and for predicting the strength of the door trim in the side impact test .

並列關鍵字

door trim ； side impact test ； material properties of plastics ； tensile test ； finite element analysis ； door trim system

參考文獻

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