Impact-resistant nacre-like transparent materials

Science ◽  
2019 ◽  
Vol 364 (6447) ◽  
pp. 1260-1263 ◽  
Author(s):  
Z. Yin ◽  
F. Hannard ◽  
F. Barthelat

Glass has outstanding optical properties, hardness, and durability, but its applications are limited by its inherent brittleness and poor impact resistance. Lamination and tempering can improve impact response but do not suppress brittleness. We propose a bioinspired laminated glass that duplicates the three-dimensional “brick-and-mortar” arrangement of nacre from mollusk shells, with periodic three-dimensional architectures and interlayers made of a transparent thermoplastic elastomer. This material reproduces the “tablet sliding mechanism,” which is key to the toughness of natural nacre but has been largely absent in synthetic nacres. Tablet sliding generates nonlinear deformations over large volumes and significantly improves toughness. This nacre-like glass is also two to three times more impact resistant than laminated glass and tempered glass while maintaining high strength and stiffness.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4376
Author(s):  
Yanqi Hu ◽  
Zekan He ◽  
Haijun Xuan

Three-dimensional woven composites have been reported to have superior fracture toughness, fatigue life and damage tolerance compared with laminated composites due to through-thickness reinforcement. These properties make them lighter replacements for traditional high-strength metals and laminated composites. This paper will present impact resistance research on three-dimensional orthogonal woven composites consisting of carbon fibers/bismaleimide resin (BMI). A series of impact tests were conducted using the gas gun technique with the impacted target of 150 mm × 150 mm × 8 mm (length × width × thickness) and the cylindrical titanium projectile. The projectile velocity ranged from 180 m/s to 280 m/s, generating different results from rebound to perforation. This paper also presents a multiscale modeling strategy to investigate the damage and failure behavior of three-dimensional woven composites. The microscale and mesoscale are identified to consider the fiber/matrix scale and the tow architecture scale respectively. The macroscale model was effective with homogenized feature. Then a combined meso-macroscale model was developed with the interface definitions for component analysis in the explicit dynamic software LS-DYNA. The presented results showed reliable interface connection and can be used to study localized composites damage at a relatively high efficiency.


1990 ◽  
Vol 213 ◽  
Author(s):  
R.L. Fleischer ◽  
C.L. Briant ◽  
R.D. Field

ABSTRACTA four-year survey of high-temperature intermetallic compounds has been aimed at identifying potentially useful structural materials for aerospace and aircraft engine applications. Since the good properties of high strength and stiffness at high temperatures are typically negated by brittleness at ambient temperature, new materials must have roomtemperature toughness or ductility. Screening has been done of 90 binary compounds with 20 different crystal structures, and 130 ternary or higher-order alloys. Testing typically included hardness vs. temperature, elastic modulus determination, and toughness evaluation via a room-temperature chisel test. Four alloy systems, including only two types that are of the simplest structures, showed substantial room-temperature toughness: Al-Ru, Ru-Sc, Ir-Nb, and Ru-Ta. Of these the last and the first are the most promising. Special features of the Ru- Ta (L1o) alloys are their room-temperature impact resistance and high-temperature strength. AIRu (B2) alloys can be tougher than the L1o structures and most are also ductile in compression at room temperature. Alloying experiments with B, Cr, and Sc show beneficial effects on ductility, oxidation resistance, and high-temperature strength.


2016 ◽  
Vol 87 (18) ◽  
pp. 2275-2304 ◽  
Author(s):  
Kadir Bilisik

In this study, the impact resistance of two-dimensional (2D) fabrics and three-dimensional (3D) preforms is explained. These fabrics and preforms include 2D and 3D woven and knitted flat and circular fabrics. Various types of soft/layered structures as well as rigid composite are outlined with some design examples for ballistic and stab threats. The recent developments in nanotubes/nanofibers and shear-thickening fluids (STF) for ballistic fabrics are reviewed. The ballistic properties of single- and multi-layered fabrics are discussed. Their impact mechanism is explained for both soft vest and rigid armor applications. Analytical modeling and computational techniques for the estimation of ballistic properties are outlined. It is concluded that the ballistic/stab properties of fiber-reinforced soft and rigid composites can be enhanced by using high-strength fibers and tough matrices as well as specialized nanomaterials. Ballistic/stab resistance properties were also improved by the development of special fabric architectures. All these design factors are of primary importance for achieving flexible and lightweight ballistic structures with a high ballistic limit.


Author(s):  
Youssef Ibrahim ◽  
Khaled H. Khafagy ◽  
Tarek M. Hatem ◽  
Hesham A. Hegazi

Abstract Tool steels are essential for any industry, being used to cut, drill, form, shear, and shape ferrous and non-ferrous materials in bulk or powder forms. Due to the harsh service environment, tool steels are engineered with superior properties that include high wear, corrosion, and impact resistance. The macro properties of tool steel alloys are acknowledged to depend upon their fine martensitic microstructure. Therefore, accurate representation of its microstructures will help to further study its behavior which shall lead in advancing and improving their properties. In the current research, a novel microstructure generator for tool steel alloys will be used to precisely simulate complex microstructures of tool steels. The novel generating algorithm along with multiple-slip crystal plasticity based model and specialize spectral solver formulations are used to investigate high-speed tools steels behavior. The spectral method for elastoviscoplastic boundary value problems implicitly uses fast Fourier transformation algorithm (FFT) by applying periodic BCs. Both quasi-static and dynamic uniaxial tensile loading in the [010] direction is applied on a RVE of AISI H11 martensitic tool steel. Validating the numerical results with the experimental results of tool steels is presented.


2019 ◽  
Vol 5 (4) ◽  
pp. eaau9490 ◽  
Author(s):  
Yang Yang ◽  
Xiangjia Li ◽  
Ming Chu ◽  
Haofan Sun ◽  
Jie Jin ◽  
...  

Lightweight and strong structural materials attract much attention due to their strategic applications in sports, transportation, aerospace, and biomedical industries. Nacre exhibits high strength and toughness from the brick-and-mortar–like structure. Here, we present a route to build nacre-inspired hierarchical structures with complex three-dimensional (3D) shapes by electrically assisted 3D printing. Graphene nanoplatelets (GNs) are aligned by the electric field (433 V/cm) during 3D printing and act as bricks with the polymer matrix in between as mortar. The 3D-printed nacre with aligned GNs (2 weight %) shows lightweight property (1.06 g/cm3) while exhibiting comparable specific toughness and strength to the natural nacre. In addition, the 3D-printed lightweight smart armor with aligned GNs can sense its damage with a hesitated resistance change. This study highlights interesting possibilities for bioinspired structures, with integrated mechanical reinforcement and electrical self-sensing capabilities for biomedical applications, aerospace engineering, as well as military and sports armors.


2015 ◽  
Vol 769 ◽  
pp. 316-319
Author(s):  
Alena Zemanova ◽  
Jan Zeman ◽  
Michal Sejnoha

Laminated glass has been developed to improve the impact resistance of brittle glass sheets and to prevent injuries and collapse of glass members. The goal of this contribution is to briefly introduce a finite element model based on the refined plate theory by Mau that can describe the response of laminated glass plates without the need for fully resolved three-dimensional simulations. Each layer is considered to behave according to the Reissner-Mindlin kinematics, complemented with membrane effects and the von Karman assumptions. The compatibility of independent layers is enforced by nodal Lagrange multipliers. Predictions of the finite element model, obtained with a MATLAB-based program LaPla (Laminated Plates) developed by the authors, are compared with simplified monolithic and layered limits and a semi-analytical solution.


2017 ◽  
Vol 21 (6) ◽  
pp. 1975-1990
Author(s):  
Yu-Chun Chuang ◽  
Limin Bao ◽  
Pey Yu Chen ◽  
Ching-Wen Lou ◽  
Jia-Horng Lin

Diverse products are delivered from the production place to different destinations, during which any impacts or shakes easily lead to the damage of products. Buffering packaging materials are thus used to absorb the energy caused by damage, thereby preserving the goods. Buffering packaging materials are commonly made of plastics and foams, which are the materials that have limited buffering effect and cannot be repetitively used. Therefore, this study proposes eco-friendly buffering sandwich-structured composites using thermoplastic polyurethane honeycomb grids and three-dimensional crimped, flame-resistant polyester nonwoven fabrics. Thermoplastic polyurethane honeycomb grids have advantages of a lightweight, a high strength, and high impact resistance. Thus, thermoplastic polyurethane honeycomb grids can be combined with flexible nonwoven fabrics that features ease of process to form environmentally friendly buffering packaging materials. Polyester nonwoven fabrics are made of differing basic weights. A total of one to three layers of polyester nonwoven fabrics serve as the cover sheets of the sandwiches, while a thermoplastic polyurethane grid serves as the interlayer in order to obtain different thicknesses. The buffering sandwiches are tested for bursting strength, air permeability, resilience rate, limited oxygen index, and drop-weight impact test, thereby characterizing their mechanical properties and buffering efficacy. The buffering sandwiches have an optimal residual impact stress of 4762 N when the polyester nonwoven fabrics have a basic weight of 150 g/m2. Moreover, the buffering sandwiches have an optimal resilient rate of 41.8% when they are composed of three-layered polyester cover sheets on both upper and lower sides, and are industrial product that qualified for use as buffering packaging.


Author(s):  
Yifan Li ◽  
Huaiyuan Gu ◽  
Martyn Pavier ◽  
Harry Coules

Octet-truss lattice structures can be used for lightweight structural applications due to their high strength-to-density ratio. In this research, octet-truss lattice specimens were fabricated by stereolithography additive manufacturing with a photopolymer resin. The mechanical properties of this structure have been examined in three orthogonal orientations under the compressive load. Detailed comparison and description were carried out on deformation mechanisms and failure modes in different lattice orientations. Finite element models using both beam elements and three-dimensional solid elements were used to simulate the compressive response of this structure. Both the load reaction and collapse modes obtained in simulations were compared with test results. Our results indicate that three-dimensional continuum element models are required to accurately capture the behaviour of real trusses, taking into account the effects of finite-sized beams and joints.


2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.


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