scholarly journals NUMERICAL AND EXPERIMENTAL STUDY OF CERAMIC/STEEL COMPOSITE FOR STRUCTURAL APPLICATIONS

2021 ◽  
Vol 27 (2) ◽  
pp. 77-86
Author(s):  
Olawale Sanusi ◽  
Olatunde Oyelaran ◽  
Mounir Methia ◽  
Anurag Dubey ◽  
Adeolu Adediran
Keyword(s):  
Numerical Study ◽  
Impact Resistance ◽  
Layered Composite ◽  
Alumina Ceramic ◽  
Steel Component ◽  
Composite Target ◽  
Backing Plate ◽  
Structural Applications ◽  
Steel Composite ◽  
Armour Steel

The Terminal ballistics is the study of science that deals with the interaction involved in two impacting bodies. This research focused on the high-impact resistance of layered composite comprising of alumina ceramic and armour steel. The composite was designed to have ceramic as the facial plate with armour steel as its backing plate. For the numerical study, the ceramic thickness was varied (6, 8, 10, 12 mm) while keeping the thickness of backing steel constant (7 mm). The projectile, 7.62 mm armour-piercing (AP), was set with a velocity of 838 m/s and made to impact the different ceramic–steel composite target configurations at zero obliquity. The study captured fracture processes of the ceramic, the deformation of projectile, and backing steel. An effective optimum thickness ratio of 1.4 (ceramic:steel; 10/7) for the ceramic/steel components with less deformation of the backing steel is found. Thereafter, the result of the numerical study was validated by experimental ballistic investigation of the determined optimum ceramic/steel ratio. The experiment corroborated the simulation results as the alumina ceramic provided efficient protection to armour steel component after a severe interaction with the impacting projectile.

Analysis of High Velocity Impact on Composite Structures

2014 ◽  
Vol 617 ◽  
pp. 104-109 ◽  
Author(s):  
Milan Žmindák ◽  
Zoran Pelagić ◽  
Maroš Bvoc
Keyword(s):  
Carbon Fibers ◽  
Composite Structures ◽  
Impact Resistance ◽  
Leading Edge ◽  
Layered Composite ◽  
Bird Strike ◽  
Out Of Plane ◽  
The Matrix ◽  
Composite Wing ◽  
Considerable Damage

In the recent years a big focus is subjected to the response of structures subjected to out-of-plane loading such as blasts, impact, etc. not only to homogenous materials, but also to heterogeneous materials, such as composites. Such form of loading can cause considerable damage to the structure. In the case of layered composite materials the damage can have several forms, starting from damage in layers up to delamination and full damage of the construction. This paper describes the investigation of shockwave propagation in composite structures caused by impact loading. The composite consists of carbon fibers in a polymer matrix, in which the fibers are much stiffer then the matrix. Finite element simulations were carried out for a “bird” strike impact on a composite wing leading edge. Results show a good impact resistance and good damping abilities of shockwaves.

scholarly journals Achieving room-temperature brittle-to-ductile transition in ultrafine layered Fe-Al alloys

2020 ◽  
Vol 6 (39) ◽  
pp. eabb6658
Author(s):  
Lu-Lu Li ◽  
Yanqing Su ◽  
Irene J. Beyerlein ◽  
Wei-Zhong Han
Keyword(s):  
Room Temperature ◽  
Extreme Environments ◽  
High Strength ◽  
Layered Composite ◽  
Al Alloys ◽  
Brittle To Ductile Transition ◽  
Transmission Electron ◽  
Structural Applications ◽  
Wear And Corrosion Resistance ◽  
New Applications

Fe-Al compounds are of interest due to their combination of light weight, high strength, and wear and corrosion resistance, but new forms that are also ductile are needed for their widespread use. The challenge in developing Fe-Al compositions that are both lightweight and ductile lies in the intrinsic tradeoff between Al concentration and brittle-to-ductile transition temperature. Here, we show that a room-temperature, ductile-like response can be attained in a FeAl/FeAl2 layered composite. Transmission electron microscopy, nanomechanical testing, and ab initio calculations find a critical layer thickness on the order of 1 μm, below which the FeAl2 layer homogeneously codeforms with the FeAl layer. The FeAl2 layer undergoes a fundamental change from multimodal, contained slip to unimodal slip that is aligned and fully transmitting across the FeAl/FeAl2 interface. Lightweight Fe-Al alloys with room-temperature, ductile-like responses can inspire new applications in reactor systems and other structural applications for extreme environments.

scholarly journals Effect of Thermal Ageing on the Impact Damage Resistance and Tolerance of Carbon-Fibre-Reinforced Epoxy Laminates

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 160 ◽  
Author(s):  
Irene García-Moreno ◽  
Miguel Caminero ◽  
Gloria Rodríguez ◽  
Juan López-Cela
Keyword(s):  
Carbon Fibre ◽  
Residual Strength ◽  
Composite Structures ◽  
Impact Resistance ◽  
Thermal Ageing ◽  
Low Velocity Impact ◽  
Impact Tests ◽  
Compression After Impact ◽  
Structural Applications ◽  
The Impact

Composite structures are particularly vulnerable to impact, which drastically reduces their residual strength, in particular, at high temperatures. The glass-transition temperature (Tg) of a polymer is a critical factor that can modify the mechanical properties of the material, affecting its density, hardness and rigidity. In this work, the influence of thermal ageing on the low-velocity impact resistance and tolerance of composites is investigated by means of compression after impact (CAI) tests. Carbon-fibre-reinforced polymer (CFRP) laminates with a Tg of 195 °C were manufactured and subjected to thermal ageing treatments at 190 and 210 °C for 10 and 20 days. Drop-weight impact tests were carried out to determine the impact response of the different composite laminates. Compression after impact tests were performed in a non-standard CAI device in order to obtain the compression residual strength. Ultrasonic C-scanning of impacted samples were examined to assess the failure mechanisms of the different configurations as a function of temperature. It was observed that damage tolerance decreases as temperature increases. Nevertheless, a post-curing process was found at temperatures below the Tg that enhances the adhesion between matrix and fibres and improves the impact resistance. Finally, the results obtained demonstrate that temperature can cause significant changes to the impact behaviour of composites and must be taken to account when designing for structural applications.

Experimental and Numerical Study of Basalt FRP Strip Strengthened RC Slabs under Impact Loads

2020 ◽  
Vol 20 (06) ◽  
pp. 2040001 ◽  
Author(s):  
Wensu Chen ◽  
Thong M. Pham ◽  
Mohamed Elchalakani ◽  
Huawei Li ◽  
Hong Hao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Study ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Impact Behavior ◽  
Impact Loads ◽  
Quantitative Measurements ◽  
Rc Slabs ◽  
The Impact

Basalt fiber-reinforced polymer (BFRP) has been applied for strengthening concrete structures. However, studies on reinforced concrete (RC) slabs strengthened by BFRP strips under impact loads are limited in open literature. This study investigates the efficiency of using BFRP strips with various strengthening layouts and anchoring schemes on the impact resistance of RC slabs. A total of 11 two-way square slabs were prepared and tested, including one reference specimen without strengthening and ten slabs strengthened with BFRP strips and/or anchors. The RC slabs were impacted by a drop weight with increasing height until slab failure. The observed failure modes include punching shear failure, BFRP sheet debonding and reinforcement fracture. The failure modes and the effects of using various strengthening schemes on the impact resistant capacity of RC slabs were examined. The quantitative measurements, such as impact velocity, indentation depth and diameter, were compared and discussed. In addition, numerical studies were carried out by using LS-DYNA to simulate the impact tests of RC slabs with and without BFRP strengthening. With the calibrated numerical model, the impact behavior of slabs with various dimensions and strengthening layouts under different impact intensities can be predicted with good accuracy.

scholarly journals Numerical Study on the Projectile Impact Resistance of Multi-Layer Sandwich Panels with Cellular Cores

2016 ◽  
Vol 13 (15) ◽  
pp. 2876-2895 ◽  
Author(s):  
Liming Chen ◽  
◽  
Bing Du ◽  
Jian Zhang ◽  
Hao Zhou ◽  
...  
Keyword(s):  
Numerical Study ◽  
Impact Resistance ◽  
Sandwich Panels ◽  
Projectile Impact

scholarly journals Strengthening of Composite Steel-Concrete Beams Openings by Adopting Different Reinforcement Methods

2019 ◽  
pp. 1-17
Author(s):  
Mohamed H. Makhlouf ◽  
Hala M. Refat
Keyword(s):  
Numerical Study ◽  
Concrete Slab ◽  
Low Cost ◽  
Composite Beams ◽  
Experimental Program ◽  
Bottom Surface ◽  
Steel Beam ◽  
Web Openings ◽  
Line Load ◽  
Steel Composite

This paper presents an experimental and numerical study carried out to investigate the flexural and shear behavior of concrete-steel composite beams with circular web openings strengthened using two different techniques around openings. The experimental program conducted on nine simply supported beams which were constructed with different variables. One steel beam and eight concrete-steel composite beams were experimentally tested. The tested beams are of 1500 mm length and BFI cross section of steel beam but composite beams were BFI steel section connected with concrete slab had 300 mm width and 70 mm depth, while this connection is done by headed stud shear connector. The tested specimens subjected to positive bending were loaded by one or two line load across the width of the concrete slab. The main parameters were the type of beams, web openings effect, location of web openings, strengthening techniques around openings externally CFRP strips and vertical steel links using steel plates placed on the top and bottom surface of beams anchored with fine threads, and number of CFRP strips layers. The effect of these parameters on the failure of modes, ultimate load, first cracking load and deflection were investigated. Moreover, a finite element models were developed by ANSYS (version 14) to simulate all the tested specimens, experimental test results were compared with FE results obtained. The experimental results showed that both strengthening systems applied in this research were remarkably increased the beam strength, and the capacity retrieve of beams without openings. This study approved that steel links technique gave more prominent simplicity of use and low cost. FEM models were in good agreement with the corresponding experimental ones. However, the calculated ultimate loads were slightly higher than the experimental ultimate loads up to 10%.

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