Free Vibration of Braided Composite Plates with a Center Hole

含中心孔編織複材平板之自由振動

蔡昆恊(Kun-Hsieh Tsai) ； 黃宗立(Chung-Li Hwan) ； 林孟儒(Meng-Ju Lin) ； 羅致卿(Chih-Ching Lo) ； 黃建立(Jiann-Lih Hwang)

《中國機械工程學刊》 38卷2期 (2017/04) Pp. 135-144

摘要

In this study, experiment and finite element analysis by software ANSYS are employed to explore the free vibration of braided composite plates, each with a center hole. First, the fiber volume fraction, braiding angle and density of braided composite plates, as well as the height-to-length ratio of a unit cell are measured. The equivalent engineering constants of the braided composite are then calculated by means of the stiffness averaging method. Secondly, the engineering constants calculated above, together with the measured density, are put into ANSYS to analyze the free vibration of the plates. Then vibration experiments of the braided composite plates are conducted, and the experimental results are used to validate the computed results. Finally, the effects that braid angle, fiber volume fraction, aspect ratio, along with the size and shape of holes have on the natural frequencies and vibration modes of our specimens are studied.

關鍵字

free vibration ； braided composite plate ； experiment ； natural frequency

並列摘要

本文利用實驗及有限元素軟體ANSYS探討含中心孔編織複合材料平板之自由振動。首先量測編織複材平板之纖維體積含有率、編織角度及密度和單位格子的高長比。然後利用勁度平均法估算編織複合材料之等校工程模數。接著將上述之工程模數及量測所得之密度輸入ANSYS，進行平板之自由振動分析。另一方面製作試片並進行自由振動試驗，並以實驗數據驗證分析結果之準確性。最後，探討編織角度、纖維體積含有率、長寬比以及孔洞的大小形狀對自然頻率及振動模態的效應。