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The paper reports an experimental investigation on the mechanical and thermal properties of multifunctional composite laminates integrated with microencapsulated phase change materials. The different microstructures were created by incorporating microencapsulated phase change materials in glass–epoxy composites at weight fraction between 0 and 20 wt.%. To characterise the mechanical properties, tension, compression and flexural tests were conducted. The scanning electron microscope studies were used to investigate the damage mechanisms associated with these loading conditions. Thermal storage capability of the multifunctional composites was characterised using heat flux meters. The apparent heat capacity of the composites was linearly proportional to the concentration of microencapsulated phase change materials. Alternative design analysis resulted in an optimised laminate configuration with high thermal storage capability coupled with excellent mechanical properties. [ABSTRACT FROM AUTHOR]

The main objective of this study was to study the effects of length, alignment and diameter distribution of the carbon nanotubes (CNTs) on the percolation threshold of nanocomposites using computational simulations. Furthermore, the effects of the aforementioned parameters on the efficiency of the produced networks are investigated. The best distribution for optimum connectivity and the lowest CNTs concentration for the onset of percolation is determined via analyzing the geometrical characteristics of carbon nanotubes. The critical volume fraction of CNTs for percolation was found to be 0.1% while the mean number of bonds per object was 1.3 at the best distribution condition. The results from this study are compared to available experimental data and good agreement was found. [ABSTRACT FROM AUTHOR]

The main objective of this study was to evaluate the residual strength of fibre reinforced metal laminates (FRMLs) with a circular hole using an effective crack growth model (ECGM). Damage is assumed to initiate when the local normal stress at the hole edge reaches the tensile strength or yield strength of composite and metal layers, respectively. The damage in constituent materials was modelled by fictitious cracks with cohesive stress acting on the crack surfaces, and the damage growth was simulated by extension of the fictitious cracks and reduction of the cohesive stress with crack opening. The apparent fracture energy of composite layers and fracture toughness of metal layers was used to define the relationships between the tensile/yield strength and the critical crack opening. Based on the global equilibrium, an iterative technique was developed to evaluate the applied load required to produce the damage growth. The residual strength of notched fibre reinforced metal laminates was defined by instability of the applied load with damage growth. The effect of hole size on the residual strength was studied and the stress redistribution with damage growth was discussed. The residual strength simulated from ECGM correlated well with experimental data in the open literature for various ARALL laminates with a circular hole. The results indicate that damage first occurs in the composite layer, followed with stable crack growth well before ultimate failure, associated with plastic yielding of metal layer at the hole edge. [ABSTRACT FROM PUBLISHER]

A new effective crack growth model (ECGM) is developed to evaluate residual strength of composite laminates with circular holes. When the local normal stress reaches the tensile strength of the unnotched laminate, damage is assumed to initiate and it propagates with increase of the applied load. The damage is modelled by a fictitious crack with cohesive stress acting on the crack surfaces and the damage growth is simulated by extension of the fictitious crack and reduction of the cohesive stress with crack opening. The apparent fracture energy (G:) is used to define the relationship between the unnotched strength and the critical crack opening. Based on the equilibrium condition, an iterative technique is developed to evaluate the applied load required to produce the damage growth. The residual strength of notched composite laminates is defined by the unstable point of the applied load with damage growth. AS4-carbon/948A1 epoxy [0/90]4s, and [0/±45/90]2s, composite laminates were manufactured and residual strength tests were conducted for composite laminates with various hole diameters and specimen widths. Effect of the damage increment on the convergence of the residual strength was investigated and the stress redistribution with damage growth in the composite laminates was discussed. The residual strength predicted from the new model correlates well with experimental data for the different laminate configurations. [ABSTRACT FROM PUBLISHER]