Qi Jialiang, Li Lun, Wang Yiqi, Gao Hang
Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education, School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China.
Polymers (Basel). 2022 Jun 28;14(13):2618. doi: 10.3390/polym14132618.
The preforming quality of carbon fiber plain-woven thermoset prepreg (CFPWTP) is critical to the performance of composite aerospace parts. The deformation ability of the CFPWTP material during preforming is affected by both the fabric woven structure and the resin viscosity, which is different from the dry textile material. Incorrect temperature parameters can enlarge the resin's viscosity, and high viscosity can inhibit fiber deformation and cause defects. This study proposes an equivalent continuum mechanics model considering its temperature-force behavior. Picture frame tests and axial tensile tests at 15 °C, 30 °C, and 45 °C are conducted to obtain the temperature-stress-strain constitutional equations. By Taylor's expansion formula and surface fitting method, the constitutive modulus of the material is obtained. Consequently, a saddle-shaped forming simulation is carried out, which is later validated by experiments. Results show that the accuracy of the predicted model is high, with 0.9% of width error and 5.1% of length error separately. Besides, the predicted wrinkles are consistent with the test in fold position and in deformation trend under different temperatures.
碳纤维平纹热固性预浸料（CFPWTP）的预成型质量对航空航天复合材料部件的性能至关重要。CFPWTP材料在预成型过程中的变形能力受织物编织结构和树脂粘度的影响，这与干纺织材料不同。不正确的温度参数会增大树脂粘度，而高粘度会抑制纤维变形并导致缺陷。本研究考虑其温度-力行为提出了一个等效连续介质力学模型。在15℃、30℃和45℃下进行了镜框试验和轴向拉伸试验，以获得温度-应力-应变本构方程。通过泰勒展开公式和曲面拟合方法，得到了材料的本构模量。随后进行了鞍形成型模拟，并通过实验进行了验证。结果表明，预测模型的精度较高，宽度误差分别为0.9%，长度误差为5.1%。此外，预测的褶皱在不同温度下的褶皱位置和变形趋势与试验结果一致。
