Thermal Expansion and Elasticity

Isaak D. G., Anderson L., and Oda H. (1992). High-temperature thermal expansion and elasticity of calcium-rich garnets. Phys. Chem. Minerals, 19 106-120. 

Because nanocomposites are made from different phases with different thermal expansion coefficients and elastic moduli, they inevitably develop residual thermal stress during cooling after sintering. Assuming the dispersion phase is spherical particulate in the matrix material, residual stresses can be developed due to differences in the thermal expansion and elastic constants between the matrix and the particles [23] ... 

Consider an ordinary substrate-ceramic coating combination. Such a composite system, prepared at elevated temperatures and subsequently cooled to room temperature, will be thermally stressed due to the usually large difference in thermal expansion and elastic moduli of the substrate and coating. These stresses often exceed the fracture strength of the ceramic component, particularly in regions close to free surface near the interface. This leads to either cracking of the ceramic part or to failure at the substrate-coating interface. 

The stress-strain behavior of thermosets (glassy polymers crosslinked beyond the gel point) is not as well-understood as that of elastomers. Much data were analyzed, in preparing the previous edition of this book, for properties such as the density, coefficient of thermal expansion, and elastic moduli of thermosets [20,21,153-162]. However, most trends which may exist in these data were obscured by the manner in which the effects of crosslinking and of compositional variation were superimposed during network formation in different studies, by... 

Until now, much research work has been done on the prediction of composite material coefficient of thermal expansion and elastic modulus by forefathers, and many prediction methods have been developed such as the sparse method (Guanhn Shen, et al. 2006), the Self-Consistent Method (Hill R.A. 1965), the Mori-Tanaka method (Mori T, Tanaka K. 1973) and so on. However, none of these formulas take into account the parameters variation with concrete age, and there is little research on the autogenous shrinkage and creep. In the mesoscopic simulation of concrete, thermal and mechanical parameters of mortar and aggregate (coefficient of thermal expansion, autogenous shrinkage, elasticity modulus, creep, strength) are important input parameters. In fact, there is abundant of test data on concrete, but much less data on mortar while it is one of the important components. Also parameter inversion is an essential method to obtain the data, but there are few studies on this so far. 

Equation (1.27) has a dimension of degrees and reveals the maximum temperature drop in the samples. The first thermal shock factor R reflects the tendency of the thermal shock resistance from strength, thermal expansion, and elastic modulus, but it is impossible to use this factor in order to make a forecast on the service life of the refractory. 

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