De-asymmetry Method for Distribution Function of Fiber Orientation in Injection Molded Composites

註塑成型復合材料纖維取向分布函數的去非對稱方法

Shanjie Zhi(職山傑) ； Xizhou Yang(楊錫洲) ； Xintian Liu(劉新田) ； Hejian Liu(劉和劍)

《中國機械工程學刊》 44卷1期 (2023/02) Pp. 67-76

摘要

Fiber orientation is a key factor in determining the mechanical properties of injection molded composites. Therefore, accurate description of fiber orientation plays an important role in the performance evaluation of injection molded composites. The relationship between the effective thickness in the thickness direction and the probability density of the fiber orientation tensor is built up. Based on it, a smooth segmented linear function of fiber orientation is proposed to obtain the cumulative distribution function of fiber orientation tensor. Considering the asymmetry and non-monotonicity of the fiber orientation distribution, a de-asymmetry method is proposed. Compared with the experimental results in the literature, the cumulative distribution function has a good fit, and the experimental results correlate well with the elastic modulus obtained by the de-asymmetry method. It could provide a reference basis for subsequent studies based on the thickness distribution of the fiber orientation tensor.

關鍵字

fiber orientation distribution ； mechanical properties ； Weibull distribution ； injection molded composites

並列摘要

纖維取向是決定註塑復合材料力學性能的關鍵因素。因此，準確描述纖維取向對註塑復合材料性能評估有重要作用。基於厚度方向有效厚度與纖維取向張量的概率密度之間的關系，提出了纖維取向的平滑分段線性函數用以得到纖維取向張量累積分布函數。考慮到纖維取向分布的近似對稱性和非單調性，提出了去非對稱化方法。與文獻中的實驗結果相比，累計分布函數具有良好的擬合優度，並且實驗結果與本方法得到的纖維取向張量預測的彈性模量有良好的相關性。可為後續基於纖維取向張量厚度分布的研究提供參考依據。