High Energy Absorption Capacity Research Articles

In-Plane crushing performance of bionic glass Sponge-Type honeycomb structures

Honeycomb structures are commonly adopted due to their superior energy absorption capacity. In this study, a new bionic glass sponge–type honeycomb structure (BSH) with a quadrilateral octagonal mesh microstructure inspired by the sea sponge structure was proposed. The in-plane crushing performance of the BSH with different geometrical parameters under different crushing speeds was investigated by ABAQUS/Explicit. The numerical findings suggested that the BSH displayed stronger energy absorption in contrast to the square, hexagonal and hierarchical honeycombs at both quasi-static and dynamic crushing conditions. More plastic hinges and more unit walls involved in deformation resulted in a high energy absorption capacity. In addition, three typical deformation modes of the BSH under different loading speeds were discussed, and the empirical model to predict the plateau stress of the BSH was established based on the shock wave theory. Finally, the effect of boundary segmentation parameter m on crushing performance was also illustrated. The energy absorption capacity reaches a maximum at m = 3 for quasi–static loading, whereas at m = 5 for dynamic loading. These findings provide valuable insights into the optimization of bionic honeycombs.

The mechanical characteristics of an aluminum foam winding CFRP composite structure under axial compression

To enhance the energy absorption properties of the energy-absorbing structure, carbon fiber-reinforced polymer (CFRPs) with higher specific energy absorption and porous material aluminum foam with better compressive characteristics were organically combined, and a lighter aluminum foam winding carbon fiber-reinforced polymer structure (CFRP-FA-FW) was designed. Through quasi-static compression testing, the deformation mode and energy absorption properties of CFRP-FA-FW under axial load were examined. The energy absorption and specific energy absorption of CFRP-FA-FW are both increased by 113.55% and 60.73%, respectively, compared to the simple composite structure CFRP-FA. Finite element simulation was used for the parametric analysis of the CFRP-FA-FW structure to assess the effects of the relative density of the aluminum foam, the fiber lay-up angle, and the thickness. The results reveal that the change in the relative density of aluminum foam has little impact on the failure deformation mode of CFRP-FA-FW under axial load; the structure has a higher energy absorption capacity and a smoother energy absorption process when the fiber lay-up angle is [0°/90°]ns and [45°]ns; the energy absorption capacity of CFRP-FA-FW is significantly improved by increasing the thickness of the carbon fiber lay-up, and the procedure is also more efficient.

Role of fibre weight fraction on low-velocity impact characteristics of abaca fibre reinforced bio-composites

This work involved an experimental study on Abaca fibre bio-composites subjected to a low-velocity impact test at 2.42 m/s to study the effect of fibre weight fraction on the impact performance. The abaca fibre reinforced composite (AFRC) specimens were fabricated with a 10% increment of fibre, varying from Wf = 20% to 50%, and their impact properties compared with each other. The impact properties such as force-time history, energy-time history, Coefficient of Restitution (CoR), Energy Loss Percentage (ELP) and Energy Absorption Ratio (EAR) were studied. A significant change in impact force and energy absorption was found as the fibre content increased in the composite. The findings show a good relationship between fibre weight fractions, composite laminate stiffness, impact load and total absorbed energy. The experimental results of the impact test show that the composite specimen with Wf = 40% has high impact energy absorption capacity with 4. 09 J 92.94 N and 4.09 J, EAR of 39.94%, CoR of 0.77 and ELP of 40.04%. Low fibre weight fraction composite has shown brittle failure, and high fibre weight fraction has shown ductile behaviour. Scanning electron microscopy (SEM) based study was used for post-impact damage analysis.

Investigating the Impact Behavior of Carbon Fiber/Polymethacrylimide (PMI) Foam Sandwich Composites for Personal Protective Equipment.

To improve the shock resistance of personal protective equipment and reduce casualties due to shock wave accidents, this study prepared four types of carbon fiber/polymethacrylimide (PMI) foam sandwich panels with different face/back layer thicknesses and core layer densities and subjected them to quasi-static compression, low-speed impact, high-speed impact, and non-destructive tests. The mechanical properties and energy absorption capacities of the impact-resistant panels, featuring ceramic/ultra-high molecular-weight polyethylene (UHMWPE) and carbon fiber/PMI foam structures, were evaluated and compared, and the feasibility of using the latter as a raw material for personal impact-resistant equipment was also evaluated. For the PMI sandwich panel with a constant total thickness, increasing the core layer density and face/back layer thickness enhanced the energy absorption capacity, and increased the peak stress of the face layer. Under a constant strain, the energy absorption value of all specimens increased with increasing impact speed. When a 10 kg hammer impacted the specimen surface at a speed of 1.5 m/s, the foam sandwich panels retained better integrity than the ceramic/UHMWPE panel. The results showed that the carbon fiber/PMI foam sandwich panels were suitable for applications that require the flexible movement of the wearer under shock waves, and provide an experimental basis for designing impact-resistant equipment with low weight, high strength, and high energy absorption capacities.

Achieving excellent strength-ductility-superelasticity combination in high-porosity NiTiNb scaffolds via high-temperature annealing

Metallic scaffolds with lightweight, low elastic modulus, and high energy-absorbing capacity are widely utilized in industrial applications but usually require post-heat treatment to enhance their comprehensive mechanical properties. However, it is unclear how to utilize the impact of β-Nb on the surrounding matrix for NiTiNb ternary alloys to achieve strength-ductility-superelasticity enhancement. Here, we prepared rhomboidal dodecahedral NiTiNb porous scaffolds with a porosity of 85.9% by additive manufacturing. Subsequently, annealing treatment was employed to drastically reduce the phase transformation temperatures and expand the thermal hysteresis. Interestingly, the 850°C annealed scaffold exhibited exceeding double compressive strength of the as-built sample, with a remarkable improvement in ductility and superelasticity. From the microstructure perspective, high-temperature annealing caused a further eutectic reaction of the unmelted Nb particles with the NiTi matrix and the transformation of mesh-like β-Nb into diffuse spherical β-Nb particles. The microstructure evolution after deformation indicated that stress-induced martensitic transformation occurred in the matrix away from the NiTi-Nb eutectic region whereas almost no martensite formed nearby β-Nb particles. Atom probe tomography characterization revealed an element diffuse zone in several nanometers surrounding the β-Nb particle, where the substitution of Nb with Ti led to a higher Ni: Ti atomic ratio, lowering transformation temperatures. Molecular dynamics simulations illustrated that β-Nb particles can not only entangle dislocations internally, acting as reinforcements but also hinder the twin growth, contributing to strain hardening. This work elucidates the influence of β-Nb particles on the deformation mechanism of the NiTi-Nb eutectic region through in-depth atomic-scale investigation, which can provide inspiration for the improvement of comprehensive mechanical properties of NiTiNb alloys.

Multi-dimensional hybridized TPMS with high energy absorption capacity

Lattice structures based on triply periodic minimal surfaces (TPMSs) have received extensive research attention due to their lightweight, tremendously high ductility, and excellent energy absorption. In this study, the advantages of several types of TPMSs-based lattice structures were integrated by proposing a multi-dimensional hybrid design for the first time. Based on the P, IWP, and FRD structures, one-dimensional (1D), 2D, and 3D hybridizations were successfully achieved by using the Sigmoid function. The technique of powder bed fusion of metal using a laser beam (PBF–LB/M) was utilized to fabricate the designed TPMS structures with Al–Si10–Mg powder. Their mechanical properties under different loading directions were investigated both experimentally and numerically. The results demonstrate that the hybridization strategy effectively modifies the mechanical behaviour of the TPMS structures. When the hybridization direction aligns parallel to the compression direction, the hybrid structure exhibits greater specific energy absorption, while vertical alignment results in a higher Young's modulus. Notably, the 2D hybrid P–FRD structure possesses the most excellent mechanical properties under parallel compression. Moreover, the 1D and 2D hybrid structures exhibit superior specific energy absorption than the uniform structure, with maximum energy absorption of 45.02% and 52.81%, respectively. The proposed hybrid design strategies are expected to accelerate the application of energy-absorbing structures in practical engineering.

Experimental and numerical study on the impact response of the steel-concrete-steel-foam-filled-tube energy absorbing structure

A novel energy absorbing structure is proposed and can be fixed on the front of protected structures to reduce the impact-induced damage. This energy absorbing structure consists of nine polyurethane foam-filled steel tubes (PUFFSTs) and a steel-concrete-steel sandwich panel (SCSSP) and is named steel-concrete-steel-foam-filled-tube energy absorbing structure (SSEAS). The present study investigates the energy dissipation characteristics and dynamic responses of SSEAS through both experimental and numerical analyses. All specimens exhibited the same failure mode, including the collapse of the centre PUFFST and the local indentation of the SCSSP. The investigated parameters contain the thickness and width of the steel tube, thickness of concrete core and the initial momentum of the drop weight. A comprehensive discussion is presented on the impact response and energy dissipation performance. The results indicate that the thinner concrete core would result in larger deformation but shallower local indentation. Additionally, raising the width and thickness of the steel tube would result in higher energy absorbing capacity and larger proportion of energy dissipation of PUFFSTs. The numerical studies also show that higher initial momentum of the drop weight would induce a longer duration and larger energy dissipation of PUFFSTs.

A hybrid bio-inspired sandwich structures for high strain rate energy absorption applications

Due to its advantages in terms of enhancing the performance of structures in the desired applications, the bio-inspired design approach has recently attracted the interest of researchers in a number of engineering disciplines. A hybrid bio-inspired design is suggested for the sandwich structures to absorb the energy of the blast loads in the current study. The sandwich structure's core, which often has a regular grid pattern resembling a honeycomb structure, is crucial to how well the panel absorbs energy. In order to achieve the best results, we first chose the structure of the core grid by taking into account potential 2D grids (polygons and multi-pointed stars) through Genetic Algorithm optimization. Next, we combined a bio-inspired bi-tubular thin-walled structure with the core grid to take advantage of its high energy absorption capacity. Finally, the performance of the suggested design is compared with four frequently implemented ones. The results show that the hybrid design has better energy absorption characteristics compared with the bionic and conventional designs presented in the literature.

On the energy absorption in a novel CoFeSiB metallic‐glass fiber/epoxy resin composite under quasi‐static and dynamic compression conditions

AbstractManufacturing and investigating metallic‐glass‐fiber‐reinforced epoxies is an important new attempt to present their potential to contribute to the aviation industry. In order to explore the energy absorption in novel CoFeSiB metallic‐glass‐fiber/epoxy resin composites, CoFeSiB/epoxy resin composite cylinders with different fiber volume fractions were prepared by a hot‐pressing method. The amorphism of the metal fibers was analyzed using x‐ray diffraction. The quasi‐static compression tests were performed on different fiber oriented samples with a diameter of 3.6 mm and a height of 7.2 mm. The sample with the fiber orientation [0°/90°] has a higher energy absorption capacity, compared to the one with the fiber orientation [0°/0°]. The dynamic‐ compression tests were performed on the [0°/0°] samples with a diameter of 3 mm and height of 6 mm at different air pressures. The compression fracture surfaces were examined by scanning electron microscope. Then the energy absorption mechanism of the composites was investigated. This study is of great significance for the energy absorption in amorphous metal fiber/epoxy composites.

Crushing analysis of square gradient hierarchical multicellular tubes

Inspired by tree fractals, a novel square gradient hierarchical multicellular tube (SGHMT) is proposed, and a finite element (FE) model of the structure is constructed using Abaqus/Explicit. The accuracy of the FE numerical model was verified using experiments, and the energy absorption characteristics of the structure under axial impact were analyzed. The results show that the high-level SGHMTs have higher energy absorption capacity and impact force efficiency (CFE) compared with the low-level SGHMTs for both the same wall thickness and the same mass, and crashworthiness is greatly improved. The energy absorption (EA) and CFE of SGHMT-3 are 11.39 and 4.47 times higher than those of SGHMT-0 under the same wall thickness condition, respectively. The EA and CFE of SGHMT-3 are 2.15 and 2.28 times higher than those of SGHMT-0, respectively, under the same mass condition. On this basis, further geometrical parameter analysis was carried out, and it was found that the structural parameters (wall thickness, hierarchy, and shape scale factor γ 1 , γ 2 ) had a significant effect on the crashworthiness of the square gradient hierarchical multicellular tubes. Finally, a comparative study with other multicellular tubes was carried out to demonstrate the superiority of the proposed square gradient hierarchical multicellular tubes compared with other multicellular tubes.

Axial and radial reversibility and energy absorption behaviors of braided shape memory composite thin-walled tubes

Braided shape memory polymer composites (SMPCs), which integrate braided structures with shape memory polymers, are well-known for their superior mechanical properties, reversible deformation, and recovery capabilities. This study focused on exploring the reusable energy absorption capacity of intelligent braided SMPC tubes. The effects of braiding structure on compression modes, mechanical properties, energy absorption, shape memory performance, and repeatability under axial and radial compression have been comprehensively investigated. The results show that SMPC tubes have a shape recovery ratio exceeding 94 % after four cycles. As the number of compressions increased, both the mechanical and energy absorption properties decreased, particularly during the first compression. Higher energy absorption capacity has been observed in SMPC tubes with larger braiding angles, up to 32.51 J, 2.3 times that of pure TPU tubes. These findings offer potential approaches for the development of high-performance reusable protective devices and lightweight intelligent structures.

Experimental and numerical crashworthiness investigation of 3D printing carbon fiber reinforced nylon origami tubes

AbstractIn this article, the crashworthiness performance of 3D printed origami tubes with variable thickness and different printing angles are investigated. First, experimental results showed that, compared with the traditional equal thickness origami tubes, the initial peak crushing force of variable thickness origami tubes (VTOT) was reduced by 41% and the specific energy absorption (SEA) had an improvement of 22%. Then, the energy absorption (EA) capacity of 3D printed origami tubes at different printing angles was measured and analyzed experimentally. It can be concluded that smaller print angles provide better EA, and the larger print angles result in a significant increase in layer‐to‐layer shear under quasi‐static axial loads, which makes the component more susceptible to buckling and cracking. Finally, the finite element method was constructed through Abaqus/Explicit to study the crashworthiness of VTOT under different mean thickness and the thickness difference in detail. As the mean thickness increases, the load‐carrying capacity and EA capacity increase during the crushing process, but the VTOT with a mean thickness of 1.2 mm has the highest SEA and CLE. The larger thickness differences can significantly improve the EA properties of the VTOT through the changing of the deformation mode.Highlights Both experimental and numerical methods were used to study origami tubes with varying thicknesses. Origami tubes printed at 0° have a higher energy absorption capacity. Variable thickness origami tubes improve the crashworthiness of traditional origami tubes.

3D Chiral Energy-Absorbing Structures with a High Deformation Recovery Ratio Fabricated via Selective Laser Melting of the NiTi Alloy.

Excellent energy-absorbing structures have been highly sought after in engineering applications to improve devices and personal safety. The ideal energy absorption mechanism should exhibit characteristics such as lightweight, high energy absorption capacity, and efficient reusability. To address this demand, a novel three-dimensional (3D) chiral lattice structure with compression-twist coupling deformation is fabricated by combining the left and right chiral units. The proposed structure was fabricated in NiTi shape memory alloys (SMAs) by using laser powder bed fusion technology. The compression experiment result indicates that the shape recovery ratio is as high as 94% even when the compression strain is over 80%. Additionally, the platform strain reaches as high as 66%, offering high-level specific energy absorption, i.e., 213.02 J/g. The obtained results are of great significance for basic research and engineering applications of energy-absorbing structures with high deformation recovery ratios.

Advanced structural and multi‐functional sandwich composites with prismatic and foam cores: A review

AbstractAdvanced sandwich structures have emerged as new multifunctional structures with low density and good mechanical performance. Sandwich composites have high strength to weight and high stiffness to weight ratio. Good thermal and sound insulation can be provided using sandwich composite materials. Sandwich composites have high energy absorbing capacity. Multifunctional sandwich composites exhibit mechanical performance and other functional properties such as energy storage, electrical conductivity, etc. Further, the core can be used for routing wires, foam filling, fluid storage, embedding bars, etc. Thus, the multifunctionality can be introduced to the resuting composite materials. This article reviews current research on innovative sandwich structures with integrally woven corrugated core, honeycomb, foam, and 3D printed core architectures, emphasizing their multifunctionality. Aspects of sandwich structure with types of face and core structure design, material design, mechanical properties, and panel performance and damage, including multifunctional benefits, are reviewed. Examples of engineering and modern uses of sandwich structures are presented, covering hypersonic vehicles, civil and marine engineering, electronics, and biological fields. A list of areas for future study initiatives is also included. This review will serve as a baseline for future studies to do more research in the same direction.Highlights A detailed review of various types of core materials and sandwich structures is presented. Sandwich structures have high energy absorbing capacity. 3D woven sandwich structures, their manufacturing and failure mechanics is discussed. Modern applications of sandwich structures are detailed.

Simulation of a multimaterial model for modified auxetic structures

Auxetic structures, which is a term used to describe materials with a negative Poisson’s ratio, show beneficial properties like a low density, a high energy absorption capacity and an increased indentation resistance. This enables applications in many fields, such as aerospace and sports industries. Given their potential, many studies have already been conducted. Previously, the geometry of a selected auxetic re-entrant structure was optimized to maximize its mass-specific energy absorption capacity for ideal usage in lightweight applications. Moreover, a homogeneous material was used, whereas the combination of multiple materials could drastically increase the performance of such structures. Hence, in this study the use of two different materials combined into a modified re-entrant structure is investigated via Finite Element simulation. The Poisson’s ratio could thus be improved, which leads toa more pronounced and longer lasting auxetic effect.

Improving the behavior of concentrically braced frame braces using a flexural damper: Experimental and numerical study

SummaryAlthough the concentrically braced frames (CBFs) systems have high lateral elastic stiffness and strength, they reflect a low seismic energy absorption capacity mainly due to their diagonal buckling under compressive loading. To overcome this problem, researchers have proposed metallic shear damper as the most popular due to its satisfactory performance and affordable cost. In this paper, an innovative metallic damper with a flexural mechanism is proposed to improve the behavior of CBF systems. It provides ease of fabrication and replacement after damage, competitive cost, and improved resistance to buckling of the CBF member. The performance of the damper was evaluated experimentally and numerically. Subsequently, two types of dampers, (a) made of rectangular flexural plates (RFP) and (b) made of I‐shaped flexural plates (IFP), were designed and evaluated. Experimental as well as numerical results indicated that both dampers provide stable and symmetrical hysteresis curves with a high energy absorption capacity. Results indicated that the IFP damper has greater stiffness (1.94–2.3 times) and ultimate strength (1.76 times) but a lower overstrength (66% less) and ductility (47% less) than the RFP damper. Moreover, design expressions were presented for the proposed damper and showed a good agreement with finite element results.

Low-velocity impact performance of integrally-3D printed continuous carbon fibre composite sandwich panels

Sandwich panels are heavily used in industrial sectors where specific mechanical properties are of utmost importance due to their high weight-stiffness ratio and energy absorption capacity. Lightweight sandwich cores with bio-inspired topologies have been used as an advanced alternative to conventional bulk cores to improve performance. Nowadays, sandwich structures comprised of core and skins are typically manufactured with two different processes and are afterwards adhesively joined together. Here, with a less time-consuming and more efficient assembly procedure in mind, an integrally 3D-printing strategy is proposed. This investigation analyses the low-velocity impact and quasi-static perforation performance of sandwich core designs inspired by the beetle's forewing trabecular structure. It was found that the core material was responsible of the rate dependence observed in the force–displacement curves. More complex finite element models than those employed here are necessary to capture all the fracture modes observed experimentally.

Quasi-static compressive and cyclic dynamic impact performances of vat photopolymerization 3D printed Al2O3 triply periodic minimal surface scaffolds and Al2O3/Al hybrid structures: Effects of cell size

In this study, Al2O3 triply periodic minimal surface (TPMS) scaffolds with cell sizes of 5 mm, 8.5 mm, and 12 mm were prepared by vat photopolymerization 3D printing, and Al2O3/Al ceramic-metal hybrid structures were subsequently obtained by the metal infiltration of AlSi10Mg. To investigate the influence of cell size on the mechanical properties of vat photopolymerization 3D printed Al2O3 TPMS scaffolds and Al2O3/Al hybrid structures, quasi-static compression and dynamic impact experiments were conducted, and the failure modes during experiments were discussed. It was shown that the quasi-static compression and dynamic impact properties of Al2O3 TPMS scaffolds gradually decreased with the increase in cell size, the compression strength decreased from 15.2 MPa to 8 MPa and the impact strength decreased from 37 MPa to 11 MPa, respectively, which was related to the stress transfer ability of the single cell. In contrast, the effects of cell size on the performance of Al2O3/Al hybrid structures were opposite. When the cell size increased, the quasi-static compression performances of the Al2O3/Al hybrid structure were greatly improved, and the compression strength increased from 175 MPa to 250 MPa. The impact resistances of the Al2O3/Al hybrid structure were further studied. The highest impact strength of the Al2O3/Al hybrid structure was 290.74 MPa. With the increase in cell size, the impact resistance of the Al2O3/Al hybrid structure had a gradual improvement trend. Under the cyclic impact, the Al2O3/Al hybrid structure showed a high impact strength and energy absorption capacity, which was mainly related to the metal phase content around the cell, i.e., the coherence of the metal phase. This study is believed to give help for the structural design of ceramic scaffolds and ceramic-metal hybrid structures.

Compression property and energy absorption capacity of 4D-printed deformable honeycomb structure

Honeycomb structures exhibit outstanding mechanical properties with specific unit cell configurations. We introduce a novel honeycomb structure that can enhance the compression property and energy absorption capacity by utilizing four-dimensional (4D) printing technology with polylactic acid (PLA) materials. In the designed honeycomb structure, the walls of the adjacent unit cells are independent, and the shape of the unit cells can be transformed between a hexagon and triangle under external loading and temperature stimulus. 4D printing technology is employed to prepare the honeycomb specimens, and the deformation processes of the innovative honeycombs are implemented. Structure I (a novel hexagonal honeycomb structure) and Structure II (a semi-triangular honeycomb structure) can be transformed into each other. Uniaxial quasi-static compression and impact tests are conducted to investigate the compression property and energy absorption capacity of the designed honeycomb structures. The results indicate that the novel honeycomb had a high compression property with Structure II, and had high energy absorption capacity with Structure I; thus, the developed honeycomb structures have broad application prospects for the multifunctional applications of honeycomb structures in the future.

A comprehensive review on in-plane and through-the-thickness auxeticity in composite laminates for structural applications

Auxetic laminates are part of a fascinating branch of materials denominated as auxetics, which display a NPR (Negative Poisson’s Ratio), an uncommon property in the engineering world. Auxeticity is at the root of enhancements in shear and indentation resistance, fracture toughness and energy absorption, making the design of NPR a desirable feat in structural engineering. In composite laminates made of conventional, i.e. positive Poissons ratio, materials, auxeticity is a result of the combination between particular angular configurations and anisotropic materials. Such laminates can be used in a wide array of engineering applications, especially those which require high energy absorption capacity, including aerospace, personal defense and sports industries. This review focuses on particular property enhancements reported in the scientific world brought about by the design and application of IP (In-plane) and TTT (Through-the-thickness) NPR fibre-reinforced polymer laminates under QSI (Quasi-static indentation), LVI (Low-velocity impact) and fatigue solicitations. Furthermore, some insight is given on some possible future paths for further investigation of this topic.