On the Reliability of Finite-Element Evaluation of the Dynamic Interaction of a Structure with the Base

Аннотация

We analyze the characteristic errors of the finite-element modeling of soil massifs by an example of the problem of vibrations of a layer on the rocky base for various types of fastening of the lateral boundary: rigid fixture, free boundary, acoustic boundary, and acoustic boundary with a column of the base. The first error is connected with the assumption that, for large distances of the boundary from the structure, the boundary conditions do not affect its behavior. The second error is caused by the use of a constant in height) elasticity modulus for a homogeneous layer of soil. The size of the domain used for modeling guaranteed the boundedness of the zone of dislocation displacements near the boundary and constant displacements in the central part of the layer. However, these displacements differed from each other and from the exact solution given by the elasticity theory. This is explained by the specific features of taking into account the effect of damping within the framework of the applied software.