MODELING OF SINGLE-LAP JOINT WITH AUXETIC ADHESIVE AS AN EFFECTIVE STRATEGY FOR JOINT STRENGTH ENHANCEMENT

• Main Author: Palma Puspaningtyas, Chatarina
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76155
• Institution: Institut Teknologi Bandung

<p align="justify"> One effective strategy for producing lightweight structures includes the use of secondary bonded joints with high-performance adhesive. In this work, we explored the concept of tailoring the adhesive bondline using microstructures exhibiting a negative Poisson's ratio (auxetic). A single lap joint (SLJ) configuration was selected as a model to prove this concept. Two SLJ models with either homogeneous or heterogeneous adhesive were developed in ABAQUS/Standard. The auxetic response in homogeneous adhesive was obtained by defining a negative value of Poisson's ratio in the adhesive part of the models. In contrast, the auxetic response in heterogeneous adhesive was obtained by explicitly building orthogonally-arranged elliptical voids in the adhesive. The interface of adherend-adhesive was built using cohesive elements with bi-linear traction-separation law. Effects of using two different adhesive models and thickness on peel and shear stresses, as well as failure mechanism and joint strength were evaluated. We found that the effect of auxetic adhesive could be effectively simulated using heterogeneous adhesive rather than the homogeneous one, where the improvement of joint strength by up to 45% was achieved. The strength improvement was due the plastically-deformed ligaments, a mechanism that could not be obtained using the homogeneous adhesive. Our proposed modeling strategy can be a starting point for modeling the adhesive bonded joints exhibiting auxeticity.