Lightweight materials and structures have attracted tremendous interests for their compelling advantages in a range of engineering problems that have placed heightened requirements in safety, environment, competitiveness and cost over recent years. As an effective approach, hybrid systems aim to take advantages and characteristics of different materials to maximize their functional roles in lightweight structures, thereby enhancing their respective material efficiency. This article provides a critical review on the advances in hybrid materials and structures for crashworthiness and energy absorption performance, in which fiber reinforced plastic (FRP), metals, cellular fillers and their hybrid configuration are discussed respectively. Attention is paid to the hybridization of different forms of FRP-FRP, FRP-metal, cellular filling materials with FRP structures, thereby demonstrating their constructive characteristics for different design goals. Crashworthiness and energy absorption performances of various hybridized materials, such as carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), aluminum/steel, metallic foams/honeycombs/lattices, are evaluated and compared in detail. After highlighting the knowledge gaps in existing literatures, this review provides an outlook on the possible future research. It is expected to gain new insights into the design of novel lightweight hybrid configurations for aerospace, automotive, nautical and railway applications. • Constituent materials and preparation technology of hybrid energy absorption structures. • Experimental characterization and modeling of hybrid energy absorption structures. • Failure mechanism and parameter analysis of hybrid energy absorption structures. • Current challenges and future developments of hybrid energy absorption structures. 

Lightweight hybrid materials and structures for energy absorption: A state-of-the-art review and outlook

The dynamic mechanical responses and damage development of cross-ply composite laminates under repeated low-velocity impact are investigated through finite element simulations with ABAQUS/Explicit. A progressive damage model for laminates, consisting of the continuum damage model, the 3D Hashin failure criterion and the damage evolution model based on equivalent displacement, is integrated with the bilinear traction-separation relationship cohesive model to simulate the damage initiation, evolution and propagation behavior of different damage modes in composite laminates. Compared with the experimental results, the established finite element model was validated through the global mechanical response and damage distribution contous. Besides, a mesh refinement study was performed by using three different element sizes. The validated model was adopted to investigate the repeated impact behaviors of composite laminates under three different energies. The qualitative conclusions about the effects of repeated impact on global mechanical response were summarized by the changes of impact force, displacement, contact time and energy absorption. Moreover, the effects of repeated impact on the damage characteristics and expansions of matrix and delamination were discussed in detail.

/pdf/numerical-investigation-on-the-repeated-low-velocity-impact-34zgzk4jzs.pdf

Numerical investigation on the repeated low-velocity impact behavior of composite laminates

A progressive damage model for pressurized filament-wound hybrid composite pipe under low-velocity impact

A three-dimensional (3-D) Finite Element Analysis (FEA) model incorporating an elastic-plastic (EP) damage model, which was implemented as a user-defined material (‘VUMAT’) sub-routine in a FEA code (‘Abaqus/Explicit’), is developed to simulate the impact response of carbon-fibre reinforced-plastic (CFRP) composites. The model predicts the load versus time and the load versus displacement responses of the composite during the impact event. Further, it predicts the extent, shape and direction of any intralaminar damage and interlaminar delaminations, i.e. interlaminar cracking, as a function of the depth through the thickness of the impacted CFRP test specimen, as well as the extent of permanent indention caused by the impactor striking the composite plate. To validate the model, experimental results are obtained from relatively low-velocity impact tests on CFRP plates employing either a matrix of a thermoplastic polymer, i.e. poly(ether-ether ketone), or a thermosetting epoxy polymer. The 3-D EP model that has been developed is shown to model successfully the experimentally-measured impact behaviour of the CFRP composites.

/pdf/a-three-dimensional-elastic-plastic-damage-model-for-12vxacauia.pdf

A three-dimensional elastic-plastic damage model for predicting the impact behaviour of fibre-reinforced polymer-matrix composites

In this paper, the mechanical response of Carbon Fibre Reinforced Polymer (CFRP) plates subjected to repeated low-velocity impacts is numerically investigated. 3D models of composite plates subjected to repeated low-velocity impacts were developed in Abaqus/Explicit software. The numerical models were validated using experimental data obtained from impact tests on CFRP plates using drop weight tower methodology through the comparison of commonly used parameters (i.e., maximum contact force, maximum impactor displacement, and energy absorption). Damage is intended as several modes for intralaminar failure such us fibre or matrix breakage and interlaminar failure (i.e., delamination). Puck failure criterion with linear strain softening was employed for acknowledging intralaminar failure. Additionally, the bi-linear traction–separation cohesive zone model was employed to account for interlaminar damage by defining zero thickness cohesive elements at the interfaces. A sequence of impacts was applied to the composite plate at three different energy levels. It was found that the impact time and the peak force increase in the sequential impacts which indicates a change in the stiffness of the laminate in sequential impacts. The analyses of the results of the damage accumulation and delamination in CFRP plates showed that most of the intra-laminar and interlaminar damage is limited to a few initial impacts in a repeated impact scenario.

Shengnan Wang

Papers

Finite element analysis of a modified progressive damage model for composite laminates under low-velocity impact

Numerical investigation on the repeated low-velocity impact behavior of composite laminates