Experimental study on low-cycle fatigue and recovery properties of viscous material for viscous damping wall

Abstract

This paper aims to study the low-cycle fatigue property and recovery properties of viscous material. The authors designed a Self-Stabilization Dynamic Sandwich-Type Shear (S-DSTS) test device, which allows the static recovery of semisolid materials that can not be achieved in the traditional rheometer. A series of recovery tests with different static recovery times and low-cycle fatigue tests with different strain amplitudes and loading frequencies were conducted on the polyisobutylene-B12 (PIB–B12) by this device. The test data on low-cycle fatigue and recovery properties of PIB-B12 were evaluated by the storage modulus, loss modulus, loss factor, velocity exponent, parameter decay ratio, and recovery coefficient. The results show that each parameter's degradation rate and degradation degree increase significantly with the rise of strain amplitude. The low-cycle fatigue property of PIB-B12 is less affected by the loading frequency, and the degradation rate and degradation degree of all parameters are similar under different loading frequencies. The PIB-B12 has excellent recoverability and static recovery showing that the mechanical parameters of PIB-B12 could restore to more than 65% and 92% of the original magnitude after short-term and long-term intervals, which ensures a reliable energy absorption property during aftershocks. The velocity exponent of PIB-B12 shows minor variations under different strain amplitudes and loading frequencies.