Multi response optimisation of mechanical properties in self-healing glass fiber reinforced plastic using grey relational analysis

[Display omitted] •The healing agent in a self-healing composite affects its mechanical properties.•Optimum set of factors and levels were determined using Grey Relational Analysis.•Tensile strength increased with higher concentration and size of microcapsules.•Flexural strength decreased with size of microcapsules. Self-healing composites belong to the class of advanced materials, where the autonomic Self-healing is achieved when a microcrack propagates through the material which triggers the healing mechanism. Microcapsules filled with healing agent were mixed with epoxy resin and reinforced with glass fiber mats to make the Self-healing GFRP composite. The aim of this paper is to study the effect of various parameters- microcapsule size, concentration and catalyst concentration on the basic mechanical properties-Tensile strength, Compressive strength and Flexural strength of the material and to find the best possible combination of parameters to optimise the mechanical properties. Taguchi Design of Experiments was adopted to conduct the experiments by varying the levels of input parameters and the output responses were recorded and converted to a single grey scale to get the optimal combination. The goodness of data was validated through ANOVA. It was found that lesser microcapsule size and concentration with medium catalyst concentration gave better mechanical properties.