Strain-Field Modifications in the Surroundings of Impact Damage of Carbon/Epoxy Laminate

Abstract

The relationship between deformation and stress is crucial for any elasto-plastic body. This paper deals with the experimental identification of the basic parameters of the composite laminate model in relation to the finite element model. Standardized tensile, impact, and post-impact tests on a carbon fiber-reinforced epoxy laminate were used. The method by which the elasticity and failure parameters were obtained from the initial components is described. In the article, the modes of initiation and complete failure of samples in tensile tests, which are compared with the simulation, are presented. Furthermore, the article deals with the issue of the generation and detection of damage by low-speed impact, which can be caused by contact with moving objects, due to improper handling or maintenance. The results of impact analysis simulations are shown in the context of strain-field distribution changes obtained with the help of digital image correlation. The results showed high agreement between the calculations and the experiments. Based on this agreement, simulations of impact damage for various energies were performed. These simulations were used to determine the approximate sizes of the affected zones in relation to the impact energy. The results are finally discussed in the context of the possible use of structural health monitoring based on strain modifications.

Impact Damage Prediction of Carbon Fiber Foam Sandwich Structure Based on Hashin Failure Criterion

“…Carbon fiber foam core structure had high specific strength and specific stiffness, good stability, corrosion resistance, structural designability and other excellent properties. It was widely used in the industrial sector [1][2][3]. However, in the daily use and maintenance process, it was often subjected to low-energy impacts from various external objects such as hailstones and maintenance tools, resulting in damage and causing significant performance degradation [4].…”

The quasi-static puncture resistance of flexible impregnated nonwovens made by filament or staple polyethylene terephthalate (PET) fibers

“…The results exhibit that the composite has good puncture resistance, the interlayer structure dissipates puncture energy to a certain extent, and the LMPET layer avoids the sliding of the filament during the needle punching process, thus improving the overall mechanical properties of the laminated composite. Due to excellent high strength and high modulus, carbon fiber (Samal et al ., 2016a, b; Samal, 2022; Vlach et al ., 2022a, b) is also widely used as an interlayer reinforcement to enhance the mechanical properties of composites. Another way is to enhance the static puncture resistance of materials by structural design and optimization.…”

Study on the Influence of Delamination Damage on the Processing Quality of Composite Laminates

“…The delamination propagation path first extends along the width direction to the center, and then along the length direction [ 25 , 26 ]. Further research showed that the damage is layer-dependent in a laminate, and different fiber materials influence the delamination resistance in different ways [ 27 , 28 , 29 ]. The closer the delamination is to the surface, the lower the bearing capacity of the specimen, and the easier it is for interface cracking, interlaminar cracking, and fiber fracture to occur.…”