5. E modeling

5.1. Characteristics of the models

The plate is not modelled since it is subject to rigid body movement. The spring mat is modeled by interface elements (3D_ INTERFACE_S). The interface behavior relationship is CZM_ELAS_MIX in which the tensile stiffness density is zero (detachment without stiffness) and the compression stiffness density is simply equal to \(k\), without other treatments. A tangential stiffness (equal to \(k\)) is also added to avoid any transverse movement.

5.2. Characteristics of the mesh

The spring mattress is cut into 20 x 1 interface elements.

5.3. Tested sizes and results

The results of*Code_Aster* are compared with the continuous reference solution and high accuracy.

Nature of results	\({U}_{A}\)	\({U}_{B}\)
Instant Continuous Solution 1	\(\frac{-4}{1125}\)	\(\frac{4}{3375}\)
Instant Continuous Solution 2	\(\frac{-4}{1125}+\frac{5}{1000}\)	\(\frac{4}{3375}+\frac{5}{1000}\)
Tolerance	\(2.0E-07\)	\(2.0E-07\)