Global-Local Finite Element Analysis of Adhesive Joints and Crack Propagation

Accurately capturing the stress distribution in an adhesive joint of aircraft structures requires discretizing the adhesive layer with a very fine finite element mesh. Because such a simulation requires high computational processing unit time, researchers are looking for alternative methods to simulate adhesive joints of aircraft structures for saving the computational processing unit time. Another high computational processing unit requiring the study of aircraft structures is the evaluation of delamination growth in adhesive joints and crack propagation in brittle materials using cohesive zone modeling along with the very fine finite element mesh for the bulk material. To reduce these computational times, a possible alternative is to use a global-local finite element method. Therefore, both the crack propagation and the characteristics of adhesive joints were studied using a global-local finite element method. Three cases were studied using the proposed global-local finite element method, including 1) an adhesively bonded double cantilever beam, 2) an adhesive lap joint, and 3) a three-point bending test specimen. Using global-local methods, in a crack propagation problem of an adhesively bonded double cantilever beam, more than 80% data storage space and more than 65% computational processing unit time requirement could be saved. In the adhesive lap joints, around 70% data storage space and 70% computational processing unit time requirement could be saved using the global-local method. For the three-point bending test specimen case, more than 90% for both data storage space and computational processing unit time requirement could be saved using the global-local method.