Comparison of low‐velocity impact behavior of thick laminated composite structure with experimental and modeling technique

The finite element model of a 7.62 mm armor‐piercing incendiary bomb penetrating lightweight composite target is established. The structure of the target plate is composed of boron carbide ceramic/carbon fiber laminate/aramid fiber laminate/damping material. The reasonable distribution position of damping material is explored by designing the material structure and geometric parameters. Genetic algorithm is used to optimize the structure of the lightweight composite target plate, and the feasibility of the optimization results is verified through experiments. The results show that under the same surface density, the energy absorption value of the target plate with a certain thickness of back layer damping is 1.36% higher than that of the target plate without damping. And the damping material on the back layer can act as a buffer layer to reduce blunt trauma caused by bullets to the human body. The surface density of the optimized lightweight composite target plate is reduced by 21.6% under the same protection capability. This work provides a theoretical foundation for the impact resistance design and optimization of lightweight composite target plates.Highlights Impact resistance performance of lightweight composite target plate is investigated. The impacting analytical model of the structure is established. The validity of the optimized impacting analytical model is verified by numerical simulation.

Section: Methodsmentioning

confidence: 99%

Impact resistance performance and structural optimization of lightweight composite target plate

Zhou,

Zheng

2024

Experimental and simulative investigation on the mechanical behavior of GFRP T‐joints subjected to low‐velocity‐impact and post‐impact tensile loading

Jin,

Zhang,

et al. 2023

To investigate the failure mechanism of the composite T‐joints subjected to low‐velocity‐impact (LVI) loading varying impact locations, a methodology composed of improved conventional vacuum‐assisted resin infusion (VARI) and LVI testing based on ASTM D 7136 is developed and employed. Moreover, the simulation is conducted to mainly reveal the damage evolution of interlaminar delamination between web and web/skin laminate based on surface‐based cohesive behavior in the commercial software of Abaqus 2020. Further, the effect of LVI loading with various distances from the web laminate to the impact location on the mechanical property and failure mode of the composite T‐joints are presented and discussed as well. By comparison, larger vertical cracks and higher residual tensile strength are found in the T‐joints impacting the corner. However, the T‐joints with the impact point near the corner have lower residual tensile strength and suffer more interlaminar delamination in the interface between web and skin, which is the most critical position of failure.Highlights GFRP T‐joints are manufactured by the vacuum‐assisted resin infusion process with a newly designed mold. The damage evolution in low‐velocity‐impact tests is presented via the quasi‐static tests and finite element simulation. Larger vertical cracks and higher residual tensile strength are found in the T‐joints impacting the corner. The T‐joints with the impact point near the corner have lower residual tensile strength. Interlaminar delamination in the interface between web and skin is the most critical factor of tensile failure.

Experimental and numerical investigation on low‐velocity impact response of sandwich structure with functionally graded core

T. S.,

Joladarashi,

Kulkarni

et al. 2023

The present research investigates optimizing the impact resistance of functionally graded sandwich structures using experimental and numerical approaches. The low‐velocity impact (LVI) responses of functionally graded sandwich composite (FGSC) with different configurations with skin material jute/rubber/jute (JRJ) and core material having epoxy and sea sand by volume fraction of sea sand at 0%, 10%, 20%, and 30%. Sandwich structures were impacted with LVI (5.89, 10.92, and 15.18 m/s), with the impactor dropped from heights of 0.5, 1, and 1.5 m with precompressed spring loads. FGSC samples are considered a deformable body, and the impactor is modeled as a rigid body using commercially accessible dynamic explicit software. The burn‐out test and weight method were used to test the core's gradience; both methods' results substantially matched, and the variance in gradation could be observed. The proposed sandwich structure characteristics are examined by energy absorption, peak force, energy loss percentage, and coefficient of restitution. Results showed that SC30S provides greater energy absorption and superior damage resistance when tested on LVI. To evaluate the accuracy of experimental findings in predicting the indentation behavior of the sandwich structure, the finite element analysis was used to compare with the experimental results. According to the examination of these proposed FGSC overall performance, they could potentially be employed as sacrificial materials for LVI applications like claddings to shield major structural components. The systematic approach used in this work serves as a standard for choosing and using FGSC effectively for LVI applications.Highlights Low‐velocity impact behavior of sandwich structures was investigated. Combining flexible skin and epoxy core enhances energy absorption. Based on impact energy levels, impact damage areas were determined. Examined sandwich structure advantages in structural and aerospace uses. In terms of time and cost, the numerical analysis method would be useful.