Seven samples of ceramic materials; glasses and marbles with different mineralogy and effective conductivities were selected. These samples were labelled from P1 to P7. These materials are classified into two types of samples, rock marbles and ceramic glasses. The rocks were two grey-red gneissic granite samples labelled P1 & P2 and the other five were […]
Category: ADVANCES IN COMPOSITE MATERIALS – ECODESIGN AND ANALYSIS
Results and discussion
Two types of multiphase composite materials have been selected, namely; wood and ceramics. As it was mentioned in section 2, in particular we investigate the effect on thermal conduction due to structural morphology in woods and structural mineralogy in ceramics. 4.1 Woods It is known that wood is a fiber-based ligno-cellulosic material (Avramidis & Lau, […]
Non-steady state(transient) techniques
In the 2nd group, a periodic or transient heat flow is established in the sample. In comparison with the first group, the transient or non-steady state techniques for thermal conductivity are appealing in that the test time is comparatively short, small specimens can be measured, and formed products can be tested (e. g. films, sheets […]
Experimental techniques
The reliability of a specific technique to measure thermal properties is determined by several factors, such as the speed of operation, the required accuracy and performance under various environmental conditions, the physical nature of material, and the geometry of the available sample. However, in most techniques the main concern is to obtain a controlled heat […]
Historical background of theoretical models
Estimation of the effective thermal conductivity of composite material has been subject of many theoretical and experimental investigations. The earliest model was proposed by Maxwell (Maxwell, 1892). He derived an expression for the simplest kind of two-phase dispersion consisting of spherical particles suspended or imbedded into a continuous medium of another material neglecting the interactions […]
The Effective Thermal Transport in Composite Materials
Bashir M. Suleiman Department of Applied Physics, College of Sciences, University of Sharjah, P. O. Box 27272, Sharjah, United Arab Emirates 1. Introduction Composite materials are promising materials, which should exhibit an improve on several aspects of the physical properties such as mechanical, thermal, electrical etc.. A composite material is a system of materials composed […]
Application of uniform temperature change, AT
Next, consider the cross-ply and angle-ply laminates subjected to a uniform temperature change of AT = -100 °C. The macroscopic strain state in each lamina is determined using the classical laminate theory analysis outlined in Section 5.3 with a lamina thickness, t, of 0.2 millimetres. The homogenized mechanical strains in the cross-ply and angle-ply laminates […]
Application of uniaxial force resultant, Nx
First, a purely mechanical loading is considered. The lamina level homogenized material properties calculated in Section 5.3 are used to determine the macroscopic state of strain in a both laminates subjected an axial force resultant, Nx, in the absence of other two force resultants, Ny and Nxy. The laminate resultants are defined in Figure 4. […]
Review of classical laminated plate theory
To illustrate the full process of using the self-consistent micromechanics method described herein, two laminate stacking sequences are investigated, the [0/90/90/0] cross-ply laminate and the [45/-45/-45/45] angle-ply laminate. For this example, the laminate level analysis is preformed using classical laminate plate theory but, finite element methods can also be used for more complex geometries and […]
Determination of influence matrix and thermal superposition vector
The influence matrix and thermal superposition vector can be extracted from the same set finite element analyses used to determine the effective lamina properties. It should be noted that both the influence matrix and the thermal superposition vector are field variables. That is, each specific geometric point within a representative volume element yields a unique […]