Mechanical behavior and damage kinetics of a unidirectional carbon/epoxy laminated composite under dynamic compressive loading

Abstract

In this work, mechanical behavior and damage kinetics of a unidirectional carbon/epoxy laminated composite (CFRP) under dynamic compressive loading were investigated. An Instron testing machine and a pulse‐shaped split Hopkinson pressure bar (SHPB) apparatus were employed to test the quasi‐static and dynamic mechanical properties of the material, respectively. Digital image correlation (DIC) combined with ultra high‐speed photography was used to study the deformation and failure process of the specimen under dynamic loading. The results show that the failure modes of the material along the main direction were strain‐rate sensitive. The failure mode along the fiber direction was observed to change from crushing followed by fiber kink banding to predominantly interlaminar delamination, longitudinal cracking and fiber buckling delamination as the strain rate increases from quasi‐static to high strain rates. Furthermore, an empirical formula for dynamic compression strength was established based on the test data. Model predictions and experimental data are in very good agreement. Finally, a simplified Zhu‐Wang‐Tang (ZWT) nonlinear visco‐hyperelastic constitutive model ZWT nonlinear viscoelastic model was developed to predict the mechanical behaviors of CFRP under dynamic impact loading. The predicted values are observed to essentially match the trends of the experimental results. This research will further improve the design of CFRP composites subjected to high‐speed impact loads during service.

Study on Dynamic Mechanical Properties of Carbon Fiber-Reinforced Polymer Laminates at Ultra-Low Temperatures

“… and stand for tensile and compression, respectively. Xie et al [ 30 ] study the dynamic compression mechanical properties of CFRP laminates under one-dimensional stress using SHPB devices. The stress–strain curves of the material at different strain rates were obtained, and the variation rule of the material strength with the strain rate was given.…”

“…According to the static mechanical experimental results of the single-layer plate at different temperatures [ 7 ], the temperature-related material parameters in the above equations can be obtained: ; the static material properties of single-layer plate at room temperature and the tensile properties at different temperatures are shown in Table 1 and Table 2 . When the reference strain rate was defined as , the strength of the single-layer plate in different directions and the corresponding material parameters are shown in Table 3 [ 30 ]. The cohesive zone model property of each composite was different.…”

Exploration of impact response and damage mechanism of discontinuous CFRP laminates subjected to low velocity impact

“…The compressive strength of the discontinuous specimen is lower than that of the UC specimen, which is consistent with that established in the theory. 32,33 The CAI strengths of the discontinuous specimens are lower than those of the UC specimens with similar damage. With an increase in impact energy, the strength retention rates of all specimens decrease gradually.…”

Experimental investigation of impact resistance and compression behavior of CF/PEEK laminates after hot‐press fusion repair with different stacking sequences

“…It is clear from the LVI tests that dynamic responses such as contact stiffness, bending stiffness, peak displacement, and total impulse increased with the ascending impact number, and residual compressive strength reduced with a consequent deterioration in structural integrity. In addition to the above studies, several authors 24,31,32 have used the digital image correlation (DIC) system to observe the compressive process of composite materials. The deformation of the specimens under the load was studied by displacement capture, and information such as specimen strain and damage mechanism can be obtained.…”