Experimental Analysis of a Nonlinear Piecewise Multi-degrees-of-Freedom System

The growing industrial demand for lightweight and low-carbon emission systems is eroding the safety factors adopted in the linear design of vehicles and structures. This exposes the ultimately nonlinear nature of mechanical systems, creating the need for a better understanding of their nonlinear behaviour. In this context, we have experimentally investigated the dynamic behaviour of a nonlinear two-degree-of-freedom mechanical system with piecewise stiffness characteristics. The system is clamped at both ends, and one constraint is directly excited by a shaker. The system allows the adjustment of non-contact gaps and stiffness of the piecewise characteristic and provides a valuable resource for the validation and verification of numerical studies in this field. The experimental results show the very rich dynamics of the system, revealing the presence of quasi-periodic, chaos, and multi-periodic responses as well as branches of bifurcating stable solutions.