Analytical determination of adhesive layer deformation for adhesively bonded double cantilever beam test considering elastic–plastic deformation

Abstract

The plastic zone at the crack front of an adhesively bonded double cantilever beam (DCB) specimen is analytically expressed considering the deformation of the adhesive layer. The plastic zone length and strain during the crack propagation are obtained, and the effect of the traction-separation profile on the DCB test results is investigated. The fracture energy is given by the area under the traction-separation curve and is not affected by the curve profile. However, the crack length of the DCB specimen is strongly affected by the adhesive deformation, leading to a calculation error in the fracture energy. Therefore, several crack length correction methods have been proposed. An analytical approach to describe the plastic zone at the crack front would help better understand DCB tests for adhesives. In this study, an analytical solution for a DCB test is discussed assuming that the adhesive layer undergoes an elastic-plastic deformation. The elastic zone of the specimen is replaced with a beam on an elastic foundation and the plastic zone with a beam having a uniformly distributed load. Influence of the plastic zone at the crack front in the DCB tests is analytically described by assuming an elastic-perfectly plastic material.

Effect of Bond-Line Thickness on Fatigue Crack Growth of Structural Acrylic Adhesive Joints

“…In particular, for highly ductile adhesives, a large fracture process zone (FPZ) generated at the crack tip must be taken into account in fracture energy calculation. A compliance-based crack estimation method has been established based on linear elastic fracture mechanics (LEFM) for the adhesively bonded DCB specimens, therefore eliminating the need to measure the crack length and FPZ length [ 52 , 53 , 54 ]. Neglecting the shear effect of the beam deflection, the equivalent crack length, , which expresses the crack length including the FPZ length, can be calculated as: where is the substrate modulus, is the moment of inertia of the substrate cross-section, and is the compliance that was obtained from the gradient of the load-displacement ( ) curve for each cycle.…”

Numerical simulation of peel test for ductile thin film along ceramic substrate: Elasto-plastic analysis

“…Several application fields related to thin films and their film/substrate adherence capability are of great interest [1][2][3]; however, delamination can occur for various reasons such as residual and thermal stresses and the difference in expansion coefficient of the film/substrate pair. In the classical peel test, the energy dissipated by mechanisms other than delamination should be accounted [4][5][6] to determine intrinsic interface properties where the local mode mixity is evaluated based on analytical results. A semi-analytical expression for the work done by bending plasticity is proposed to provide a precise value of the interface fracture energy [7].…”

Numerical assessment of strain rate in an adhesive layer throughout double cantilever beam and end notch flexure tests

“…This data enables the creation of accurate models that can be used to design stronger and more efficient joints and able to sustain the loads expected in the case of a collision. 1,2 Although the procedures for determining the fracture behaviour in adhesives are well known, for example, through the double cantilever beam (DCB) tests for mode I, at quasi-static loads, the same cannot be said for dynamic conditions. Some authors have studied the effect of the strain rate on adhesive fracture toughness but without specifying the procedure used to calculate the strain rate.…”

“…This data enables the creation of accurate models that can be used to design stronger and more efficient joints and able to sustain the loads expected in the case of a collision. 1,2…”