Comparative investigation of dynamic damping and fracture in viscoelastic dampers with two different interfacial bonding types: molecular dynamics simulations and device tests

초록

Conventional flat-plate viscoelastic dampers (VEDs) often experience cracking failure at the interface between the viscoelastic material (VEM) layer and the steel plate. The selection of an appropriate interfacial bonding method is crucial, because it directly determines whether the viscoelastic damper can maintain long-term stable performance. In this study, molecular dynamics simulations and experimental methods are combined to investigate the interfacial mechanical properties of VEDs in shear and tension-compression deformation modes with two bonding types, Chemlok and epoxy resin. A model of the VEM composite-steel plate interface is constructed using Materials Studio software to simulate the interfacial bonding structure. The Polymer Consistent Force Field is employed to characterize and define the microscopic interactions between individual atoms and molecular chains. The effects of temperature, frequency, strain amplitude, and crack length on the dynamic properties of the damper under sinusoidal loading are investigated. The storage modulus, loss modulus, and energy dissipation decrease with increasing temperature and increase when the frequency increases. An increase in the strain amplitude causes a decrease in the storage modulus and loss modulus but an increase in energy dissipation. Initial cracks result in a decrease in the storage modulus, loss modulus, and energy dissipation. The effect of temperature, strain rate, and crack length on the tensile and shear fracture behaviors of VEDs is analyzed. The peak stress of the damper decreases with increasing temperature and crack length while increasing with loading rates. Compared with the damper with epoxy resin bonding, the damper with Chemlok interfacial bonding has greater energy dissipation capacity and interfacial bonding strength. The molecular simulation results reveals that the Chemlok interface structure exhibits a maximum increase of 48.49 % in storage modulus and 13.98 % in loss modulus compared to epoxy resin. Additionally, the fracture curve analysis indicates a 27.53 % elevation in stress peak value. Dampers dynamic properties tests at 15.5 degrees C under 0.5 Hz sinusoidal loading demonstrates that the Chemlok interface achieves a maximum enhancement of 27.60 % in storage modulus and 12.03 % in loss modulus at 12 mm amplitude when compared to the epoxy resin. These findings provide crucial insights for designing more durable VEDs with optimized interfacial bonding configurations, which have great potential for application in seismic, wind-induced and precision instrument vibration control, etc.

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