结构参数对复合材料V型构件固化变形影响试验及解析分析
Experimental and analytic analysis of the structure parameters on process-induced distortions of V-shaped composite parts

为研究结构参数对复合材料V型构件固化变形的影响，完成了针对V型构件厚度、拐角半径、拐角角度及铺层等结构参数的变形影响研究试验。基于剪力滞后理论和弯曲理论，利用解析法建立了考虑结构参数影响的复合材料V型构件固化变形预测模型，利用模型预测了V型构件的回弹变形并分析了不同结构参数对V型构件回弹变形的影响机制。结果表明：回弹变形随着厚度的增大而减小，厚度为1~3 mm之间，角度回弹变形差异最大在30%左右；回弹变形与拐角角度的补角呈约为0.014的比例；拐角半径的不同导致变形的差异不超过5%；准各向同性铺层试验件展现了最大回弹变形，0°铺层的变形减小了23.5%，90°铺层几乎不发生变形。模型分析结果表明，厚度主要通过弯曲刚度和剪切变形两方面影响回弹变形；铺层引起的力学性能和泊松效应的变化是使回弹变形有较大区别的主要原因；V型构件直边变形最大为0.20°，对回弹变形影响较大。变形预测结果与试验结果对比验证了解析法模型的准确性。 In order to study the influence of structure parameters on process-induced distortions of V-shaped composite parts, a series of experiments were performed to analysis the effect of structure parameters including part thickness, part radius, part angle and lay-up. Based on the shear-lag theory and bending theory, an analytical model considering the effect of structure parameters was developed to predict the spring-in of V-shaped composite parts and the influence mechanism of different structure parameters on spring-in with the model was analyzed. The results show that spring-in decreases with the increase of the thickness and the maximum variation of spring-in angle is about 30% when thickness is between 1 mm and 3 mm. There is a proportion relationship whose value is about 0.014 between spring-in angles and part angle. The differences of spring-in angles which result from different radius are less than 5%. The test pieces with quasi-isotropic lay-up exhibit the biggest spring-in angles. The spring-in angles of 0° lay-up pieces decrease by 23.5% and 90° pieces almost have no spring-in. Analysis results show that the influence of thickness on spring-in should consider its effect on bending stiffness and shear deformation; Mechanical properties and Poisson's effect differences caused by lay-up are the main reasons for spring-in diversity; The maximum distortions of flange is 0.20°which has greatly influences on spring-in. The comparison between simulation results and experiment verifies the accuracy of analytical model.