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Purpose: The purpose of this paper is to provide a summarization and review of the present author's main investigations on failure modes of reticular metal foams under different loadings in engineering applications. Design/methodology/approach: With the octahedral structure model proposed by the present authors themselves, the fundamentally mechanical relations have been systematically studied for reticular metal foams with open cells in their previous works. On this basis, such model theory is continually used to investigate the failure mode of this kind of porous materials under compression, bending, torsion and shearing, which are common loading forms in engineering applications. Findings: The pore-strut of metal foams under different compressive loadings will fail in the tensile breaking mode when it is brittle. While it is ductile, it will tend to the shearing failure mode when the shearing strength is half or nearly half of the tensile strength for the corresponding dense material and to the tensile breaking mode when the shearing strength is higher than half of the tensile strength to a certain value. The failure modes of such porous materials under bending, torsional and shearing loads are also similarly related to their material species. Originality/value: This paper presents a distinctive method to conveniently analyze and estimate the failure mode of metal foams under different loadings in engineering applications. [ABSTRACT FROM AUTHOR]

Purpose – This paper computationally estimates the constitutive relationships of composite materials reinforced by single walled carbon nanotubes (SWNT). Design/methodology/approach – A multiscale analysis is considered. At the nanoscale level, molecular dynamics (MD) are used to predict the stiffness for an equivalent beam. A BEM solver for the elasticity problems is extended to allow the presence of inclusions and hence is used to model a RVE for the composite matrix with the equivalent nanotube beams. A genetic algorithm (GA) is developed to generate an initial population of anisotropic materials based on FEM. The GA evolves the population of properties of anisotropic materials till a material is found whose mechanical response is the same as that of the nanocomposite. Findings – The overall process is suitable for the constitutive relationships estimation according to the verification process outlined. Research limitations/implications – The present work is limited to 2D linear problems. However, extending it to 3D non-linear applications is straight forward. Practical implications – The present technique could be used to estimate properties of NCT composites, hence practical applications such as aeroplane structures or turbine blades could be analysed using commercial finite element software. The present methodology could be used to estimate non-mechanical properties such as the thermal and electric properties. Originality/value – The present computational technique has never been presented in the literature. [ABSTRACT FROM AUTHOR]