Experimental and numerical investigation on compression after impact behavior of hygrothermal aged CFRP laminates

Abstract

In the paper, a detailed experimental and numerical investigation of compression after impact (CAI) behavior of hygrothermal aged T300 985LV carbon/ epoxy composites is presented. Rectangular fabric laminates are damaged by low-velocity impact, and moisture absorption conditioning is carried out. The moisture absorption curves agree with Fick's law, with a moisture equilibrium rate of 0.84% at 1392 h. Then, CAI experiments are carried out on moisture saturated specimens at different temperatures. The effects of hygrothermal environments on CAI strength are obtained with an interpretation of corresponding mechanism. Furthermore, finite element analysis based on hygrothermal mechanics formulation and incremental Newton-Raphson mixed iteration equation is established. The numerical results are in good agreement with the experimental ones, with an accuracy of up to 92%, which demonstrates the effectiveness of the established numerical model. The results show that the CAI strength of 85 RH% hygroscopic saturated laminates is decreased by approximately 12% at 85 C and 17% at 128 C. Additionally, the allowable compression value of 3546 μϵ is obtained for T300 985LV composite laminates, which is useful for applications in civil aircraft design. K E Y W O R D Scompression after impact, finite element analysis, hygrothermal aged, impact damage, moisture absorption | INTRODUCTIONCarbon fiber reinforced plastic (CFRP) is widely used in aerospace, marine and other engineering industries. [1,2] Compared with conventional materials, CFRP is characterized by the advantages of high specific strength, high specific stiffness, and excellent fatigue characteristics. [3][4][5][6][7] The percentage of CFRP used in civil aircraft ranges from 25% for the A380 to 50% for the later B787, which indicates that the usage of composite is increasing in primary components for aircraft structures. [8] Since the environment that the composite structure is exposed to significantly affect its performance, it must be accounted for during design. The most important aspect of the CFRP is temperature and moisture (hygrothermal), [9][10][11][12] which are crucial for understanding these effects and considering them in composite design. In addition, the impact damage is another factor that significantly affects composite properties. The impacts (i.e., tool drop, runway gravel, and hail) cause through-thickness stress waves in

Improvement of interfacial adhesion of CuO nanostructured carbon fiber reinforced polymer composites

“…The greater the interfacial interaction, the more energy is absorbed since energy can be transmitted from the polymer to the fiber across the interface more easily. [37] The WCF/CuO/BPA epoxy resin composite, which was created with eight seeding cycles, 60 mM CuO concentration, and 12 h of treatment, grew the most CuO F I G U R E 6 Variation of absorbed impact energy of samples as a function of time F I G U R E 7 Investigation of load-deflection response of composites under impact loading nanostructures and, as a result, absorbed the most impact energy, 74.8% better than the bare WCF/BPA epoxy resin composite. Additionally, the time taken to failure was increased by 166% in comparison to the bare WCF/BPA epoxy composites as shown in the Figure 6.…”

Hygrothermal resistance of large tow carbon fiber and its reinforced polymer composites

“…Furthermore, CFRP demonstrates greater resistance to corrosion, fatigue, and creep failure compared to other FRP materials. [5][6][7] In China, the market for CFRP in structural reinforcement is experiencing rapid growth, with an annual increase of over 25%. In 2021, the demand for CFRP in the construction reinforcement sector reached 3846 tons, accounting for 4.5% of the total demand.…”

Influence of the electrochemical treatment level of carbon fibers on the compression after impact property of carbon fiber/epoxy composites

“…When the interlayer cracks caused by impact and the initial delamination defects merge in the width direction of the laminate, the CAI strength of the laminate decreases more obviously. Huang et al [ 9 ] investigated the effect of hygrothermal environments on the compression after impact of polymer composites. The results indicated that the CAI strength of 85 RH% hygroscopic saturated laminates is decreased by approximately 12% at 85°C and 17% at 128°C.…”

“…When the interlayer cracks caused by impact and the initial delamination defects merge in the width direction of the laminate, the CAI strength of the laminate decreases more obviously. Huang et al [9] investigated the effect of hygrothermal environments on the compression after impact of polymer composites. The results indicated that the CAI strength of 85 RH % hygroscopic saturated laminates is decreased by approximately 12% at 85 C and 17% at 128 C. Although there are many reports on the CAI properties of composites, there are relatively few reports on the influence of matrix-fiber interface on the CAI properties of composites, and there is also a lack of in-depth analysis of the physical and chemical state of fiber surface and the influence of interfacial properties on the CAI properties of composites from a microscopic perspective.…”