Improvement of the dynamic and seismic response of non-structural rocking bodies through the ability to change their geometrical configuration

The protection of non-structural elements is having an increasing interest in the scientific literature. Many non-structural elements undergo to a rocking motion when they are subjected to base excitation. For instance, cabinets and racks for both civil and industrial use fall into this class. This paper aims to improve the dynamic and seismic behaviour of a rocking body under base excitation by reducing the amplitude of the rocking motion and consequently reducing the likelihood of their overturning. To achieve such objective, the body is modelled as an assembly of rigid parts connected with deformable devices that allow the body to change its geometrical configuration during the motion. Although the model presented in this paper is derived for a specific configuration of the body, such model can be easily generalized to describe similar non-structural elements. The improvement of the behaviour of the body due to its ability to deform is assessed with an extensive parametric analysis that is performed considering both one-sine pulse and seismic excitation. The results show that the deformation of the assembly that occurs before and after the start of the rocking motion improves the performances of the body.