Ciardiello Raffaele, Fiumarella Dario, Belingardi Giovanni
Department of Mechanical and Aerospace Engineering, Politecnico di Torino, 10129 Torino, Italy.
Interdepartmental Centre J-Tech@PoliTO-Advanced Joining Technologies, Politecnico di Torino, 10129 Torino, Italy.
Polymers (Basel). 2023 Jul 25;15(15):3160. doi: 10.3390/polym15153160.
Mechanical testing of glass-fibre-reinforced composite (GFRP) plates made of twill fabric and a thermoplastic recyclable infusion resin is presented. The considered thermoplastic resin, ELIUM, is made of poly-methylmethacrylate and can be infused with properly tuned vacuum techniques, in the same manner as all liquid resin. Tensile, flexural, and drop-dart impact tests were carried out to assess the mechanical properties of the composites considering different fabrication conditions, such as the different degassing pressure before infusion and three different infusion vacuum pressures. The work reports a methodology to infuse ELIUM resin at a relatively high vacuum pressure of 0.8 bar. X-ray microtomography analysis showed that the produced laminates are free of defects, differently from what was reported in the literature, where void problems related to a vacuum infusion pressure higher than 0.3-0.5 bar were pointed out. Vacuum pressure values influence the mechanical characteristics of the laminate: when higher vacuum pressures are adopted, the mechanical properties of the GFRP laminates are enhanced and higher values of elastic modulus and strength are obtained. On the other hand, degassing the resin before infusion does not influence the mechanical properties of the laminates. A maximum bending and tensile strength of 420 and 305 MPa were reached by using the vacuum infusion of 0.8 bar with an elastic modulus of 18.5 and 20.6 GPa, respectively. The density of the produced laminates increases at higher vacuum infusion pressure up to a maximum value of 1.81 g/cm with the fibre volume fraction of each laminate.
本文介绍了由斜纹织物和热塑性可回收灌注树脂制成的玻璃纤维增强复合材料（GFRP）板的力学测试。所考虑的热塑性树脂ELIUM由聚甲基丙烯酸甲酯制成，可以通过适当调整的真空技术进行灌注，与所有液体树脂的灌注方式相同。进行了拉伸、弯曲和落镖冲击试验，以评估复合材料在不同制造条件下的力学性能，例如灌注前的不同脱气压力和三种不同的灌注真空压力。该工作报道了一种在0.8巴相对较高真空压力下灌注ELIUM树脂的方法。X射线显微断层扫描分析表明，所生产的层压板没有缺陷，这与文献报道不同，文献中指出了与高于0.3 - 0.5巴的真空灌注压力相关的孔隙问题。真空压力值会影响层压板的力学特性：当采用较高的真空压力时，GFRP层压板的力学性能会增强，并且会获得更高的弹性模量和强度值。另一方面，灌注前对树脂进行脱气不会影响层压板的力学性能。通过使用0.8巴的真空灌注，分别获得了420和305兆帕的最大弯曲和拉伸强度，弹性模量分别为18.5和20.6吉帕。所生产层压板的密度在较高的真空灌注压力下会增加，最高可达1.81克/立方厘米，具体取决于每个层压板的纤维体积分数。
