Taguchi Analysis of Bonded Single-Lap Joint in Hemp Fiber Composite

Abstract

The adhesively bonded joints in composite structures are widely used in aerospace and automobile fields. Hemp epoxy composites are better alternative due to its lower specific gravity and higher toughness. . The joining process is inevitable in the application of such composites. The mechanical behaviour of such joints depends on the strength of the composite, adhesive strength and adhesion phenomenon between substrate and adhesive. The influence of overlap length, adhesive layer thickness and cure temperature on the performance of adhesive joints investigated experimentally. The influence of these parameters on the static behaviour of the joint was studied using design of experiment approach. L9 orthogonal array was used for experimental design. It was found that cure temperature of adhesive predominantly governs joint behaviour followed by adhesive layer thickness and overlap length. To obtain joint strength in the working limits, an empirical relationship between governing parameters and response was developed. Through the analysis it was observed that optimum strength of bonded joint was obtained with overlap length of 25 mm, adhesive layer thickness of 0.5 mm and cure temperature of 50⁰C.