Adhesively Bonded Joints
Peter Schmidt, Ulf Edlund
VINNOVA/NFFP (National Aviation Engineering Research Programme)
Simulations using the Finite Element (FE) method play an important role in the product development process. The analysis of a bonded structure using a commercial FE-program is, however, not a straight-forward task due to the thinness of the adhesive layer: modelling the thin layer using geometrically three-dimensional FE results in very large models and in practice only simple geometry and loading situations typical for test specimens can be modelled in this way.
In a number of earlier projects we have used the geometrically two-dimensional character of the joint as a basis to develop a simplified description of the joint. This results in a easy-to-use structural element, a shell element, consisting of three geometrically coinciding layers. This approach makes it possible analyse large structures encountered in vehicle industry.
The lack of a reliable method for prediction of the failure load is another a severe problem encountered in practice. Our approach is to use a material model which also models the failure process in the material. This means that the failure load is obtained as a computational result (the maximum of the load-displacement curve). This eliminates the need for a postulated failure criterion.
In this project, the approach above will be developed in two directions. Firstly, the possiblity to model the adherends as elastic-plastic will be introduced. Secondly, the possibility of interlaminar failure behaviour in the case of composite adherends will be modelled.
Page responsible: Ulf Edlund
Last updated: 2008-02-20