Study On Mechanical Properties Evolution Of CFRP Laminates After High And Low Temperature Cycle

Carbon fiber reinforced resin plastic (CFRP) can be widely used in aerospace fieldsdue to its amazing properties. But aircrafts will endure many adverse factors duringservice, such as temperature, humidity and shock, which will lead to performancereducement of CFRP. Currently, the many studies focus on high temperatureperformance of CFRP, but very limited researches committed on low temperatureperformance of that, especially the properties after low and high temperature cycling.The aim of this paper is to do some researches on performance evolution of CFRP afterhigh temperature, low temperature and cycling treatment, and the hygrothermal actionof CFRP composites were also analyzed. Finite element models of CFRP laminatesendure different environments will be established to simulate the static mechanicalproperties and impact resistance.In this paper, the G803fiber reinforced914resin composite laminates were treatedunder different environments, which include low temperature(-30℃), hightemperature(150℃) and temperature cycling(between-30℃and150℃). The bending,compression and impact test were carried out to evaluate the performance evolution ofCFRP. The morphology of laminates was detected by three-dimensional ultra-depthmicroscopy, scanning electron microscopy. The structure of CFRP was probe by Fouriertransform infrared spectroscopy and DTA. Then hygroscopic properties and damagemechanism of laminates were also investigated at the same time. At last, ABAQUSsoftware was utilized to simulate those evolutions.The results of bending, compression and impact show that mechanical properties oflaminates decreased after treated under those temperature environments. The rates ofmoisture absorption and final absorption, equilibrium moisture content were allincreased obviously after treated by temperature cycling, and increased with the numberof cycles. The results of FTIR and DTA show that the chemical structures of alllaminates did not changed, that means there was no reaction occurred during thereaction. The damage modes of impact included potholes, cracks and delamination, andthose damages will more and more serious with the time increasing. It can be seen fromthe infinite simulation, the mechanical performance of CFRP was decreased after ageing,and fiber layers both warp and weft can be damaged more easily than±45°, which agreewith that of experience.