Thermomechanical effects during impact testing of WC/Co composite material

2020 ◽  
Vol 241 ◽  
pp. 112054 ◽  
Author(s):  
Eligiusz Postek ◽  
Tomasz Sadowski
Author(s):  
Chian-Fong Yen ◽  
Robert Kaste ◽  
Jian Yu ◽  
Charles Chih-Tsai Chen ◽  
Nelson Carey

Design of the new generation of aircraft is driven by the vastly increased cost of fuel and the resultant imperative for greater fuel efficiency. Carbon fiber composites have been used in aircraft structures to lower weight due to their superior stiffness and strength-to-weight properties. However, carbon composite material behavior under dynamic ballistic and blast loading conditions is relatively unknown. For aviation safety consideration, a computational constitutive model has been used to characterize the progressive failure behavior of carbon laminated composite plates subjected to ballistic impact conditions. Using a meso-mechanics approach, a laminated composite is represented by a collection of selected numbers of representative unidirectional layers with proper layup configurations. The damage progression in a unidirectional layer is assumed to be governed by the strain-rate dependent layer progressive failure model using the continuum damage mechanics approach. The composite failure model has been successfully implemented within LS-DYNA as a user-defined material subroutine. In this paper, the ballistic limit velocity (V50) was established for a series of laminates by ballistic impact testing. Correlation of the predicted and measured V50 values has been conducted to validate the accuracy of the ballistic modeling approach for the selected carbon composite material. The availability of this modeling tool will greatly facilitate the development of carbon composite structures with enhanced ballistic and blast survivability.


2011 ◽  
Vol 217-218 ◽  
pp. 1170-1173
Author(s):  
Wei Wei Qiao ◽  
Hui Wang ◽  
Yan Hua Zhao ◽  
Yi Xia Han

We investigate the mechanical properties of Poly Vinyl Chloride (PVC)/ acrylnitrile-butadiene-styrene copolymer (ABS) composite material with an impact testing machine,a material testing machine and other accessory devices. The result shows that the mechanical properties of PVC/ABS composite are a function of composition, the addition of ABS improved the mechanical properties of PVC/ ABS composite,the impact strength and elongation at break rise significantly with increasing ABS content in PVC/ABS composite and appears maximum value,While the tensile strength and modulus almost decrease monotonously with increasing ABS content in PVC/ABS composite.


Author(s):  
B. Rajesh ◽  
M. L. S. Devakumar

The purpose of this paper is to investigate the mechanical properties of kevlar fiber and jute fiber reinforcement. Nowadays the composite materials are widely used materials. Having wide range of applications due to its light weight, high strength and low cost. These composite materials are now being explored in applications of aerospace and automotive industries. In the present work, the composite material is prepared with intermediate aramid fabric layer (Kevlar) which is high strength fiber and it is combined with jute fabric reinforced epoxy composite to increase the strength of kevlar. This composite material is tested for mechanical properties like flexural, tensile & impact strength are calculated with UTM (universal testing machine) for flexural, tensile tests and impact testing is done with impact testing machine. Through this test results the impact strength of the composite material is calculated. The energy dissipation by impact test of jute and kevlar fabric composite and strength of fibers will be analyzed by scanning electron microscopy (FESEM). Thermo gravity analysis (TGA) and differential thermal analysis (DTA) is carried out. Through these test results it can conclude that the jute can be combined with the kevlar where the impact is primary considerations like bulletproof vests, automobile bodies, tyres etc. The usage of jute in all kevlar applications will increase the strength of kevlar by reducing the usage of Kevlar and cost will be minimized.


2019 ◽  
Vol 2 (2) ◽  
pp. 105-109
Author(s):  
Tünde Anna Kovács ◽  
Zoltán Nyikes ◽  
Lucia Figuli

Abstract The goal of this work was to invent a high energy absorbing composite material. This composite needs to be able to attach on the building's surfaces and increase blast-resistance. In this innovation, the test samples were reinforced with aramidfiber, glass fiber and carbon fiber and tested by Charpy pendulum impact testing machine. During the tests, the aramid and glass fiber reinforced composites showed good resistance and high energy absorption against impact load.


Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.


2020 ◽  
Vol 1 (12) ◽  
pp. 36-39
Author(s):  
L. V. Iyashvili ◽  
Yu. A. Vinnichenko ◽  
A. V. Vinnichenko

The purpose of the study is a quantitative assessment of the yield of dentinal fluid on the surface of the treated dentin of the tooth when restoring its structure with a composite filling material. To achieve this goal, digital images of the coronal parts of the teeth having formed carious cavities were used; virtual models of hard tissues of teeth recreated using specialized computer programs; A computer program that provides the ability to accurately determine the area of the treated dentin tooth. The results made it possible to draw the following conclusions: with an increase in the depth of the carious cavity, the amount of dentin fluid that can stand out on its surface (1–2 mm from the tooth cavity) sharply increases; with an increase in the area of the formed carious cavity (more than 30 mm2), the risk of release of a critical mass of dentinal fluid (more than 0.4 mg), which can adversely affect the strength of the adhesive interaction between the composite material and the hard tissues of the tooth, increases significantly; the same dynamics is observed with increasing time, at which there is the possibility of free exit of dentinal fluid to the surface of the cavity prepared for filling (more than 45 seconds).


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