COHESIVE MODELS FOR DAMAGE EVOLUTION IN ADHESIVE JOINTS USING FINITE ELEMENT

Murilo Ferreira Brandão¹; Carlos Alberto Cimini Júnior¹

¹ UFMG

doi:10.20906/CPS/CILAMCE2017-0887

Resumo

In the last years, composite materials have been widely used for structural applications such as aeronautical, automotive and others, in which high structural performance is necessary. However, joining composite components may not be trivial. Considering their nature, bonding appears to be the natural choice for joining composites. The use of structural bonded joints has consequently increased due to the benefits this type of joint can offer with respect to the mechanical fastening efficiency. More uniform stress distributions, lower maintenance costs and improved fatigue resistance are some advantages, among others. However, to improve accuracy of numerical failure predictions for adhesively bonded joints design, inclusion of different damage modes and damage growth cohesive zone models (CZM) are necessary. Both static (material strength) and dynamic (fracture mechanics) based criteria are important in the design. Different damage modes can occur, such as intraply open (mode I) or shear (mode II) cracks, and interply debonding or delamination. The use of cohesive elements within the Finite Element Method (FEM) in conjunction to adequate failure criteria is desirable to accurately describe failure of bonded joints. In this work, the commercial FEM platform Abaqus® will be used to verify the best approach to predict the strength of different configuration adhesively bonded joints. Numerical predictions will be compared to experimental results. Parametric studies will be performed to verify the effect of overlap, adhesive thickness and adherent geometry in the joint strength.

Palavras-chave: FEM - Finite Element Method; composites materials; adhesive bonded joints; cohesive elements