複合材料產品落地試驗之研究

Study on The Drop Test of Composite Material Product

楊秋蘭(Chiu-Lan Yang)

指導教授 ： 陳夏宗

中原大學/工學院/機械工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500510

摘要

3C產品設計朝向輕、薄、短、小是未來產業不可避免的趨勢，落地衝擊實驗是評估該產品功能尤其是安全與品質的重要指標。以目前業界所使用的衝擊試驗準則，對於3C產品而言並無詳盡規範要求。另一方面，以電腦軟體模擬落地試驗模擬來縮短產品開發時間是未來之趨勢，實際的落地測試量測與模擬比對的相互驗證已是重要課題。
本研究的目的應用模態分析方法修正材料在受到落下衝擊產生大變形狀態下之材料參數。利用簡單之PC及PCB平板作個別及組合式之落下試驗，同時於實驗中對落下之衝擊G值做快速傅利葉轉換FFT以獲得材料振動頻率，應用ANSYS軟體做模態分析以確認材料自然頻率，分析中獲得各材料在受衝擊下之自然頻率，由分析之自然頻率數值與實驗數值比對可加以修正各材料在不同高度落下模擬時之材料參數。
由本研究發現，材料在落地衝擊產生大變形行為下，其材料參數不同於傳統機械性質分析之參數。研究中利用簡易模型作重複性之落下試驗，應用模態分析方法修正材料在受到衝擊產生大變形狀態下之材料參數，不但可藉此建立各材料衝擊分析之資料庫，同時對於未來3C產品設計可提供有效之預測。

關鍵字

落地試驗模擬 ； 複合材料產品 ； 落地衝擊測試

並列摘要

The purpose of this study is to establish a simple and repeatable drop/impact testing system for portable 3C products. When implementing this system, the drop direction, drop speed, and drop angle can be controlled in an accurate way. The signal from the accelerometer in the system can also be precisely read and recorded. The experimental results were used to verify the accuracy of simulation predictions. In addition, the method of modal analysis was applied to estimate the material parameters, such as the component weight, the Young modulus, the poisson’s ratio, and the density of the product suffering from large deformations as impacted to the ground. The product to be tested was well clamped so that the drop angle can be repeatable. A combination of CCD and mirror was used to catch the image of the product as soon as it impacted to the ground. A computer-aided image processing was thus implemented to derive the real spatial angle of the drop. Both the PC and PCB boards were used as the testing materials in this study.
The drop impulse, in unit of G (＝9.81m/sec2), was estimated to derive the vibration frequency of the material using fast-Fourier-transform (FFT).The ANSYS package then was used to undertake modal analysis and to obtain the natural frequency of the testing material.
The results show that the material parameters should be modified when the material is suffering from the large deformation due to a drop.

並列關鍵字

drop/impact test ； Composite Material Product ； drop test simulation

參考文獻

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