scholarly journals Bioinspired Design of Building Materials for Blast and Ballistic Protection

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Yu-Yan Sun ◽  
Zhi-Wu Yu ◽  
Zi-Guo Wang
Keyword(s):  
Composite Materials ◽  
Building Materials ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Major Constituent ◽  
Major Contributor ◽  
Energy Absorption Capacity ◽  
High Toughness ◽  
Ballistic Protection ◽  
Abalone Shell

Nacre in abalone shell exhibits high toughness despite the brittle nature of its major constituent (i.e., aragonite). Its specific structure is a major contributor to the energy absorption capacity of nacre. This paper reviews the mechanisms behind the performance of nacre under shear, uniaxial tension, compression, and bending conditions. The remarkable combination of stiffness and toughness on nacre can motivate the development of bioinspired building materials for impact resistance applications, and the possible toughness designs of cement-based and clay-based composite materials with a layered and staggered structure were discussed.

scholarly journals Experimental Studies on Punching Shear and Impact Resistance of Steel Fibre Reinforced Slag Based Geopolymer Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Srinivasan Karunanithi
Keyword(s):  
Energy Absorption ◽  
Steel Fibre ◽  
Impact Load ◽  
Impact Resistance ◽  
Experimental Studies ◽  
Absorption Capacity ◽  
Punching Shear ◽  
Geopolymer Concrete ◽  
Energy Absorption Capacity ◽  
Ultimate Failure

The study was focused on slag based geopolymer concrete with the addition of steel fibre. The slag based geopolymer concrete was under shear load and sudden impact load to determine its response. The punching shear represents the load dissipation of the material and the energy absorption capacity of the geopolymer concrete to impact load. The various percentage of steel fibre in the slag based geopolymer concrete was 0.5%, 1.0%, and 1.5%. Overall the dosage 0.5% of steel fibre reinforced slag based geopolymer shows better results with a punching shear of 224 kN and 1.0% of steel fibre incorporated geopolymer concrete had the better energy absorption capacity with 3774.40 N·m for first crack toughness and 4123.88 N·m for ultimate failure toughness.

High and Low Speed Impact Characteristics of Nanocomposites

2015 ◽  
Vol 1105 ◽  
pp. 62-66 ◽  
Author(s):  
Saud Aldajah ◽  
Yousef Haik ◽  
Kamal Moustafa ◽  
Ammar Alomari
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Impact Testing ◽  
Energy Absorption Capacity ◽  
Low Speed ◽  
High Speed Impact ◽  
Bulletproof Vest ◽  
Impact Characteristics ◽  
The Impact

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

Mechanical Characterization of Extended-Chain Polyethylene (ECPE) Fiber-Reinforced Composites

1995 ◽  
Vol 29 (16) ◽  
pp. 2092-2107 ◽  
Author(s):  
Forrest Sloan ◽  
Huy Nguyen
Keyword(s):  
Composite Materials ◽  
Energy Absorption ◽  
Test Methods ◽  
Absorption Capacity ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Energy Absorption Capacity ◽  
Extended Chain ◽  
Reinforcing Fibers

Composite materials reinforced with extended-chain polyethylene (ECPE) fibers are unlike typical stiff and brittle composite materials such as graphite/epoxy or fiberglass. The high ductility and energy absorption capacity of the ECPE reinforcing fibers gives these composites a unique mechanical response which makes them ideally suited for a variety of applications. However, this dissimilarity with more common materials requires special consideration of mechanical properties testing. In this paper, the mechanical behavior of ECPE-fiber-reinforced composites is investigated using standard composite test methods. Results of these tests are presented and discussed based on the properties of the ECPE reinforcing fibers and on the assumptions inherent in the test methods. ECPE/epoxy composites are characterized by high ultimate tensile strength, high tensile modulus, low shear modulus and strength, and viscoelastic response to loading. The highest available combination of fiber strength and strain-to-failure gives this material ductility and energy absorption capacity significantly higher than other common composite materials. Applications of ECPE composites are discussed.

scholarly journals Experimental Study on Impact Absorption Capacity of Various Expanded Materials for Rock Shed

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yusuke Kurihashi ◽  
Naochika Kogure ◽  
Shin-ichi Nitta ◽  
Masato Komuro
Keyword(s):  
Energy Absorption ◽  
Impact Resistance ◽  
Material Testing ◽  
Absorption Capacity ◽  
Rock Falls ◽  
Energy Absorption Capacity ◽  
Continuous Increase ◽  
Practical Applications ◽  
Mountainous Regions ◽  
Absorption Performance

In recent years, there has been a continuous increase in the intensity of natural disasters. Slope disasters such as rock falls occur along coastlines and in mountainous regions. Rock shed structures are implemented as measures to prevent rock fall damage; however, these structures deteriorate over time, and their impact resistance also decreases. As a supplementary measure, a method employing foam material as a cushioning material has been used in practical applications. However, the effect of the compressive strength characteristics on the cushioning performance of foamed materials has not been studied thus far. Therefore, in this study, falling-weight impact-loading tests involving various fall heights were performed to examine the absorption performance of various expanded materials. Moreover, we examined the case where core slabs were layered to effectively exploit the absorption performance of the expanded materials. The results of this study are summarized as follows: (1) the transmitted impact penetration stress-strain curves right under the loading points of various expanded materials exhibit properties similar to those obtained from the results of material testing. However, in the case of expanded materials with high compressive strengths, the compressive stress from the results of material testing tends to be lower. (2) In the case of expanded materials with high compressive strengths, with and without core slabs, the distribution of the transmitted impact stress is large, and the energy absorption capacity is high. (3) In this experiment, the energy absorption capacity was found to double when core slabs are layered, regardless of the type of expanded material used. This suggests that expanded materials with high compressive strengths may contribute towards a higher improvement in energy absorption capacities, by using layered core slabs.

scholarly journals Impact Energy Consumption of High-Volume Rubber Concrete with Silica Fume

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Hai-long Li ◽  
Ying Xu ◽  
Pei-yuan Chen ◽  
Jin-jin Ge ◽  
Fan Wu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Energy Absorption ◽  
Silica Fume ◽  
Impact Energy ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Rubberized Concrete ◽  
Energy Absorption Capacity ◽  
Fine Aggregates

Adding rubber to concrete aims to solve the environmental pollution problem caused by waste rubber and to improve the energy absorption and impact resistance of concrete. In this paper, recycled rubber particles were used to replace fine aggregates in Portland cement concrete to combine the elasticity of rubber with the compression resistance of concrete. Fine aggregates in the concrete mixes were partially replaced with 0%, 20%, 40%, and 60% rubber by volume, and the cement in the concrete mixes was replaced with 0%, 5%, and 10% of silica fume by mass. The properties of the concrete specimens were examined through compressive strength, splitting tensile strength, flexural loading, and rebound tests. Results show that the compressive strength of concrete and the splitting tensile strength decreased to 11.81 and 1.31 MPa after adding silica fume to enhance the strength 37.8% and 23.7%, respectively, and the dosage of rubber was 60%. With the addition of rubber, the impact energy of rubberized concrete was 2.39 times higher than that of ordinary concrete, while its energy absorption capacity was 9.46% higher. The addition of silica fume increased its impact energy by 3.06 times, but the energy absorption capacity did not change significantly. In summary, the RC60SF10 can be used on non-load-bearing structures with high impact resistance requirements. A scanning electron microscope was used to examine and analyze the microstructural properties of rubberized concrete.

High-Performance Impact-Resistant Concrete Mixture for Transportation Infrastructure Applications

2019 ◽  
Vol 2673 (12) ◽  
pp. 628-635 ◽  
Author(s):  
Kamal Baral ◽  
Jovan Tatar ◽  
Qian Zhang
Keyword(s):  
Energy Absorption ◽  
High Performance ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Flexural Behavior ◽  
Cementitious Composites ◽  
Repeated Impact ◽  
Energy Absorption Capacity ◽  
Transportation Infrastructures ◽  
The Impact

Engineered cementitious composites (ECC) is a class of high-performance fiber-reinforced cementitious composites featuring metal-like strain-hardening behavior under tension and high ductility. The highly ductile behavior of ECC often results in high impact resistance and energy absorption capacity, which make ECC suitable for applications in structures that are prone to impact damages, like exterior bridge girders, bridge piers, and crash barriers. In a recent study, a new ECC mixture has been developed using domestically available polyvinyl alcohol (PVA) fibers and regular river sand in replacement of imported PVA fibers and fine silica sand that are normally used in other ECC mixtures. The newly developed mixture, with improved local accessibility of raw materials, enables structural-scale applications of ECC in transportation infrastructures. To evaluate the suitability of the mixture for impact-resistant structures, in this paper, the tensile and flexural behavior of the newly developed material were characterized under pseudo-static loading and high strain-rate loadings up to 10−1 s−1. Direct drop-weight impact test was also conducted to assess the impact resistance and energy absorption capacity of the material. It was ensured that the ECC mixture maintains high tensile strain capacity above 1.8% under all tested strain rates. Regarding the damage characteristics, energy absorption capacity and load-bearing capacity during repeated impact loadings, ECC was found to have 75% higher energy dissipation capacity compared with regular reinforced concrete specimens and superior damage tolerance. The research results demonstrated that the newly developed ECC has a great potential to improve the impact resistance of transportation infrastructures.

Development of Composite Structures for Ballistic Protection

2007 ◽  
Vol 537-538 ◽  
pp. 151-159 ◽  
Author(s):  
Gabriella Faur-Csukat
Keyword(s):  
Material Properties ◽  
Composite Structures ◽  
Epoxy Resins ◽  
Absorption Capacity ◽  
Reinforced Composites ◽  
Low Velocity ◽  
Ballistic Performance ◽  
Energy Absorption Capacity ◽  
Fabric Structure ◽  
Ballistic Protection

The mechanical behaviour and ballistic performance of carbon, glass (E and S type), aramide and polyethylene fabric reinforced composites with different epoxy resins were studied. The specimens −produced by hand lay-up method− were qualified by low velocity (Charpy and drop weight tests) and high velocity (two different bores ballistic) impact tests. The energy absorption capacity of the composites were found to be strongly affected by material properties of reinforcing fibre, type of fabric structure and elasticity of resin.

Impact resistance and energy absorption capacity of concrete containing plastic waste

2018 ◽  
Vol 176 ◽  
pp. 415-421 ◽  
Author(s):  
Rajat Saxena ◽  
Salman Siddique ◽  
Trilok Gupta ◽  
Ravi K. Sharma ◽  
Sandeep Chaudhary
Keyword(s):  
Energy Absorption ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Plastic Waste ◽  
Energy Absorption Capacity

Investigation on the thermal insulation properties of lightweight biocomposites based on lignocellulosic residues and natural polymers

2017 ◽  
Vol 31 (11) ◽  
pp. 1497-1509 ◽  
Author(s):  
Petronela Nechita ◽  
Ştefania Miţa Ionescu
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Thermal Insulation ◽  
Building Materials ◽  
Low Cost ◽  
Absorption Capacity ◽  
Building Industry ◽  
Natural Polymers ◽  
Lignocellulosic Residues ◽  
Composite Samples

Due to their advantages (low cost, non-toxic, biodegradable, abundant, low density and very good mechanical properties), the lignocellulosic residues were widely used in the last time as reinforcements in composite materials with applications in the building industry. Besides these wastes, expanded perlite (EP) and natural polymers are promising candidates for the building industry, based on their specific characteristics and economic advantages. In this article, the results are presented regarding the thermal insulation properties of composite materials based on EP and natural polymers (starch polymer matrix reinforced with lignocellulosic wastes). The samples of composite materials were obtained from the laboratory and characterized in terms of the main specific properties of building materials, such as thermal conductivity/resistance, water absorption capacity, apparent density and image analyses by scanning electron microscopy. The obtained results have highlighted the values for thermal conductivity of composite samples between 0.05 and 0.11 (W/mK), similar to those materials currently used in building thermal insulation.

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