Compression and bending properties of regularly arrayed short fiber reinforced composite laminates: Experimental and numerical analysis

Abstract Unidirectional arrayed chopped strands (UACS) are made by introducing regularly distributed slits into continuous fiber prepregs, which show better flowability and formability while maintaining high strength and modulus. In this research, the quasi‐static compression and three‐point bending tests were carried out on quasi‐isotropic continuous fiber laminates and UACS laminates. The results illustrate that the compressive modulus and strength of UACS laminates are 53.38 GPa and 489.58 MPa, respectively, which maintain relatively high mechanical properties. The bending strength of UACS laminates decreased by 7.3%, but its bending modulus remained stable. Additionally, UACS laminates exhibit better resistance to shear and delamination damage while retaining good bending properties. To further explore the mechanical behavior of UACS laminates, finite element models were established to numerically analyze the mechanical properties and damage mechanism of laminates under compressive and bending loads. The present model could accurately simulate the mechanical properties of UACS laminates, and the errors of the numerical analysis results of the compression modulus and strength are 6.03% and 4.05%, respectively. From the analysis of the damage mechanism, the regularly arrayed slits ensure the UACS laminates have lower energy release rates during damage, which enables stable damage evolution and plays a positive effect in reducing the damage area and inhibiting delamination. Highlights The response of UACS under compression and bending loads was studied. The effect of slits on the damage of UACS laminate was revealed. The bending damage distribution of UACS laminates was studied. The difference between conventional CFRP and UACS is analyzed.