A methodology is presented for bounding all higher moments of the local hydrostatic stress field inside random two phase linear thermoelastic media undergoing macroscopic thermomechanical loading. The method also provides a lower bound on the maximum local stress. Explicit formulas for the optimal lower bounds are found that are expressed in terms of the applied macroscopic thermal and mechanic...

We make progress towards proving the strong Eshelby’s conjecture in three dimensions. We prove that if for a single nonzero uniform loading the strain inside inclusion is constant and further the eigenvalues of this strain are either all the same or all distinct, then the inclusion must be of ellipsoidal shape. As a consequence, we show that for two linearly independent loadings the strains ins...

We consider an energy minimization problem for a two-component composite with xed volume fractions. We study two questions. The rst is the dependence of the minimum energy on the constraints and parameters. The second is the rigorous justi-cation of the method of Lagrange multipliers for this problem. We are able to treat only cases with periodic or aane boundary condition. We show that the con...

Composites made from two linear isotropic elastic materials are considered. It is assumed that only the volume fraction of each elastic material is known. The composite is subjected to a uniform hydrostatic strain. For this case lower bounds on all rth moments of the dilatational strain field inside each phase are obtained for r ≥ 2. A lower bound on the maximum value of the dilatational strain...

The response of a neo-Hookean fiber composite undergoing finite out-of-plane shear deformation is examined. To this end an explicit close form solution for the out-of-plane shear response of a cylindrical composite element is introduced. We find that the overall response of the cylindrical composite element can be characterized by a fictitious homogeneous neo-Hookean material. Accordingly, this...

The effect of porosity on the thermal conductivity and the coefficient of thermal expansion of composites obtained by infiltration of Al-12 wt % Si alloy into graphite particulate preforms has been determined. Highly irregular graphite particles were used to fabricate the preforms. The thermal conductivity of these composites gradually increases with the applied infiltration pressure given the ...

analytical detection of cracking in connections of steel moment resisting frames using simple damage indices is important since these cracks are not visible unless the connections are uncovered. in this paper, applicability of three cumulative damage indices for detection of cracking in a cover plate welded moment connection is investigated. the damage indices considered in this study are based...

This paper presents the bidirectional evolutionary structural optimization (BESO) method for the design of two-phase composite materials with optimal properties of stiffness and thermal conductivity. The composite material is modelled by microstructures in a periodical base cell (PBC). The homogenization method is used to derive the effective bulk modulus and thermal conductivity. BESO procedur...

Serum total lactate dehydrogenase (LDH) was estimated serially for up to 15 days in 110 patients with head injuries who had no extraneural injury. Increase in LDH activity generally indicated the degree of parenchymal brain damage. The prognostic value of LDH was established by correlating its activity with clinical criteria such as duration of unconsciousness and post-traumatic amnesia, type o...

We develop a general procedure for estimating the effective constitutive behavior of nonlinear dielectrics. The procedure is based on a variational principle expressing the effective energy function of a given nonlinear composite in terms of the effective energy functions of the class of linear comparison composites. This provides an automatic procedure for converting well-known information for...