Vibrations of discrete-continuous models of low structures with a nonlinear soft spring

In the paper discrete-continuous models with a local nonlinearity are proposed for the dynamic investigations of low structures subject to kinematic excitations caused by transverse waves. The models consist of rigid bodies and of elastic elements which only undergo shear deformations, while the local nonlinearity is represented by a damper and a nonlinear spring. It is assumed that the nonlinear characteristic of the spring is of a soft type. In the paper this characteristic is described by four nonlinear functions. In the discussion a wave approach is used. Numerical calculations are performed for the models with two, three and four rigid bodies for a harmonic kinematic excitation. They focus on the investigation of the effect of the local nonlinearity expressed by various functions on displacements of selected cross-sections of the elastic elements in the considered models, and on the determination of the application ranges of these functions.