SIMULATION OF STRUCTURAL BEHAVIOUR OF FIBRE METAL LAMINATE JOINTS

摘要

In recent years Fibre Metal Laminates (FML) have been developed as an alternative to monolithical aluminium for use in aircraft structures. FML consists of a built-up material, comprising thin layers of aluminium alternated by layers of glass fibre reinforced epoxy. The built-up material displays advantageous properties in terms of fatigue, corrosion and fire resistance. This paper deals with the development of numerical models for simulating the damage behaviour of joints in fibre metal laminates. The focus is placed on joints fastened by rivets, being numerically challenging, and still highly relevant in several instances for materials such as FML and CFRP. A detailed model for FML skin based on the finite element method has been developed and validated extensively. In this model each layer is discretized by solid elements and damage mechanisms, such as matrix cracking, fibre failure and interlaminar delamination, are treated separately. A model for damage behaviour of rivets comprising plasticity and tensile failure has been additionally developed. In combination with the model for the skin simulations of the structural behaviour of riveted lap joints were carried out. Experimental tests have been performed to validate the model. In this paper the failure models of the skin material and rivets are presented, followed by an introduction to experimental tests of lap joints. Numerical models of the joint tests are created and simulation of the static behaviour of the joints is introduced. Thereby both unloading and reloading behaviour is studied, andcomparison with the experimental data is performed. Finally a summary and conclusions are provided and recommendations for future research are given.