模压工艺对玻璃纤维增强聚丙烯复合材料层合板力学性能的影响

利用热模压工艺制备玻璃纤维增强聚丙烯（GF/PP）复合材料层合板，通过差示扫描量热（DSC）法试验分析，确定相变参数，运用ANSYS有限元分析，将复合材料热力学参数与温度的非线性关系定义到材料特性中，研究模压成型过程中温度场变化情况，为模压成型工艺制度的确立提供理论指导和依据。以压缩强度、层间剪切强度和冲击韧性作为力学性能评价指标，采用响应曲面法探讨和分析制备工艺对GF/PP复合材料层合板力学性能的影响，得到最优模压工艺制备参数，获得最高复合材料层合板力学性能，为GF/PP复合材料自动铺放奠定铺放工艺基础。试验结果表明:模压加热工艺参数对复合材料层合板力学性能的影响度（从大到小）依次为:热压温度、热压时间、热压压力。较优的模压加热工艺参数为:热压温度228℃、热压时间6 min、热压压力1.1 MPa，在此工艺条件下制备的GF/PP复合材料层合板，层间剪切强度为31.12 MPa，压缩强度为100.96 MPa，冲击韧性为2.27 kJ/cm2。 

Influence of molding press on mechanical properties of glass fiber reinforced polypropylene composite laminates

The glass fiber reinforced polypropylene (GF/PP) composite laminates were prepared by hot molding press. Phase transition parameters were obtained by using differential scanning calorimetry (DSC) method. The variation characteristics of temperature field on the moulding processing of GF/PP composites was studied by using ANSYS finite element analysis, which provides a theoretical guidance and basis for optimizing the molding press process. The nonlinear relationship between thermodynamic parameters of composite and the temperature were defined into the material properties. The mechanical performance evaluation index of the material was evaluated by measuring the compression strength, interlaminar shear strength and impact toughness. The effect of preparation process on the mechanical properties of GF/PP composite laminates was discussed and analyzed using response hook surface methodology. The optimized molding press preparation parameters and the mechanical performance of composite laminates were obtained which laid the technology foundation for the automated placement of GF/PP composite. Test results show that the influence degrees of molding press process parameters for the mechanical performance of composite laminates are as follows:heating press temperature, heat holding time and heat holding pressure. The better molding press heating process parameters and the mechanical performance are as follows:heating temperature of 228℃, heating holding time of 6 min, holding pressure of 1.1 MPa and interlaminar shear strength of 31.12 MPa, compression strength of 100.96 MPa, impact toughness of 2.27 kJ/cm².