Determination of Cohesive Laws of an Acrylic Adhesive and theirApplication to Estimation of Adhesively Bonded Lap Joint Strengths

Abstract

Structural acrylic adhesives have been special interest because those adhesives are cured at roomtemperature and can be bonded to oily substrates. To use those adhesives widely for structural bonding, it isnecessary to clarify the methodology for predicting strengths of bonding structures with those adhesives.In this study static strengths of lap joints with an acrylic adhesive were estimated based on cohesive zonemodel. At first, by using Arcan type adhesively bonded specimens, the traction-separation laws of the acrylicadhesive under mode 1 and 2 loadings were determined by means of simultaneous recording the J-integral andthe opening displacements in the directions normal and tangential to the adhesive layer, respectively.Then, the tensile shear tests of single lap joints with the acrylic adhesive were conducted. Theexperimentally obtained strengths of these joints were compared with simulated ones by using FEM packageABAQUS, wherein the cohesive laws were simplified to trapezoidal shape based on the above tractionseparationlaws. As a result, the experimental strengths of these joints well agreed with simulated ones.