Introduction

Mechanical device for the protection of structures subject to dynamic actions which can be connected in series or in parallel to the structure to be protected in order to vary the mechanical characteristics of the system and control the general dynamic behavior. The device represents a new multi-purpose rheological element that can be used in various applications including: vibration isolation, vibration absorption, shock absorption, energy dissipation, other applications based on force-displacement rheological behavior (energy harvesting, sensors and actuators).

Technical features

The device is a new multi-purpose rheological element, usable for vibration isolation, vibration absorption, shock absorption, energy dissipation, other applications based on force-displacement rheological behavior (energy harvesting, sensors and actuators). It consists of two steel caps prepared for connecting the device to the structure and to the ground. The connection with the structure is made through vertical bars that can slide inside the bushings in order to have only the exchange of horizontal forces. The ends of the device are connected via a vertical connecting rod with spherical hinges in series with a polyurethane spring. The set of components described is pre-compressed by means of pretensioned ropes. The head of the connecting rod is connected to the spring by a group of wires. The initial prestress of the device by pretensioning the external ropes determines the instability of the vertical connecting rod in the initial equilibrium position and therefore the presence of a negative stiffness response branch. Observed the fundamental principles and formulated the technological conceptualisation; prototype under development; TRL 2; 18-24 months to the market.

Possible Applications

• Isolation devices and shock absorbing devices;
• Damping devices with tuned masses;
• Dissipative bracing of structures, infrastructures;
• Mechanical actuators.

Advantages

• Compact device, obtaining high control forces with small dimensions;
• High levels of pretension;
• Compressed elements are not susceptible to instability;
• Multi-directional and versatile response.