At present, high-damping rubber materials, widely used in the field of engineering seismic isolation, generally have the problems such as narrow effective damping temperature range, low damping loss factor and strong temperature dependence, which lead to prominent dependence of temperature and load conditions of the isolation performance of high-damping rubber isolation bearings. Research and development of high-performance high-damping rubber materials with broad effective damping temperature range, high damping loss factor and weak temperature dependence are very urgent and necessary to ensure the safety of the seismic isolation of engineering structures. This paper mainly reviews the recent progress in the research and development of high-damping rubber materials using nitrile butadiene rubber (NBR), epoxidized natural rubber (ENR), ethylene propylene diene rubber (EPDM), butyl rubber (IIR), chlorinated butyl rubber (CIIR), and bromine butyl rubber (BIIR). This is followed by a review of vulcanization and filler reinforcement systems for the improvement of damping and mechanical properties of high-damping rubber materials. Finally, it further reviews the constitutive models describing the hyperelasticity and viscoelasticity of rubber materials. In view of this focus, four key issues are highlighted for the development of high-performance high-damping rubber materials used for high-damping rubber isolation bearings.

In this paper, a viscoelastic (VE) tuned inerter damper (TID) that replaces conventional stiffness and damping elements with a cost-effective VE element is proposed to achieve a target-based improvement of seismically protected buildings. The semi-analytical solution of the optimal tuning frequency ratio of the VE TID is presented based on a two-degree-of-freedom (2-DOF) system, accounting for inherent structural damping disturbances, and then is extended to a MDOF system via an effective mass ratio. The accuracy of the semi-analytical solution is validated by comparing the numerical solution. Finally, numerical analyses on a viscoelastically damped building and a base-isolated building with optimally designed VE TIDs under historical earthquakes are performed. The numerical results validate the target-based improvement capability of the VE TID with a modest mass ratio in avoiding large strokes or deformation of existing dampers and isolators, and further reducing the specific mode vibration.

A novel two-stage friction damper (semi-metal composite material) proposed and tested in the paper, some of which can be connected in parallel with regular isolation bearing to form a new composite type combined isolation bearing. It can significantly improve the matching of isolation parameters under multi-level earthquakes (helping to improve the applicability and sustainability of the structure) and enhance the isolation effect. Traditional methods, such as adding lead cores to laminated rubber bearings (LNR) to obtain LRB, or adding metal dampers, viscous dampers, etc., often encounter problems such as insufficient matching of isolation parameters (such as excessive slice force under frequent earthquakes and insufficient damping ratio under rare earthquakes), or space limitations due to the addition of dampers. To address these limitations, this paper proposes this new structure and uses the theory of elasticity mechanics to establish a set of methods for calculating the internal force and deformation of the damper, which can be used for the compact design of the internal structure and connecting components of the damper. After assembly and testing, it shows the damper can ensure reliable operation with a compact size and providing satisfactory damping performance. Independent mechanical performance tests confirm the shape characteristics of the force–displacement hysteresis curve, the appropriate preload torque value, and the technical parameters under variable displacement and variable speed loading conditions. The full-scale combined isolation bearing (LNRF) test verifies the working principle of the damper and the stable bone-shaped force–displacement hysteresis curve output, and compared with LNR, the equivalent viscous damping ratio increases by −14.8% (due to the increase in stiffness), 7.1%, 20.2%, and 24.0% at shear angles of 100%, 200%, 250%, and 300%, respectively. This indicates that the new combined isolation bearing structure and damper design method proposed in this paper can assist in the design of combined bearing structures and the development of products of various specifications, and suits for application in isolation buildings, bridges, and other engineering projects.