Discrete-continuous models in the analysis of low structures subject to kinematic excitations caused by transversal waves

The paper consists of two parts. In the first one the influence of shear forces on vibration frequencies of a short beam is investigated utilizing: Timoshenko equations, simplified Timoshenko equations and classical wave equation. In the second part, two discrete-continuous models are proposed for dynamic investigations of the low structures subject to kinematic excitation caused by transversal waves. The models consist of rigid bodies and elastic elements which undergo only shear deformations. In the second multi-body model an additional elastic segment is located between the lower rigid body and remaining elements. In the discussion a wave method is applied, which utilizes the wave solution of the equations of motion. Numerical calculations are made for the model consisting of three rigid bodies. They concern on determination of the amplitude-frequency curves and investigation of the effect of diversified mechanical and geometrical properties of the segment on resonant amplitudes.