The Finite Element Method in Adhesive Joint Design

The Finite Element Method in Adhesive Joint Design 

The Finite Element Method (FEM), which means method of elements with limited size, is a powerful tool for numerical solutions of mechanical problems of elastic and plastic materials. The basis is the calculation of linear equation systems by a computer. The system to calculate, i.e. structme, is divided into fitting elements 

In FEM simulation, the elastic joints can be modeled, for example, as a spring element, shell and volume element. An explanation follows in the next section. 

In the representation of the joint by spring elements, the mechanical properties of the adhesive are given with the generalised elasticity factor of stiffness. The physical units are the same as of the modulus. With the joint dimension it is possible to calculate the spring constant of the joint by the dimensionless quantity 

This spring element is also used to control the joint geometry and not allow it to exceed the maximum permissible deformations. If, for example, we assume a shear stiffness of 0.5 MPa and a section of an adhesive joint of 200 mm length with 15 mm width and 4 mm layer thickness, the spring constant can be calculated as follows  

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