Hysteresis and damping properties of steel and polypropylene fiber reinforced recycled aggregate concrete under uniaxial low-cycle loadings

Early-age behavior and mechanical properties of cement-based materials with various types and fineness of recycled powder

Mechanical properties of fully recycled coarse aggregate concrete with polypropylene fiber

Enhancing the elastic modulus of concrete prepared with recycled coarse aggregates of different quality by chemical modifications

A modification of Coulomb's law of friction uses a variable coefficient of friction that depends on a power law in the energy of mechanical oscillation Through the use of three different exponents: 0, 1/2 and 1; all commonly encountered non-viscous forms of damping are accommodated The nonlinear model appears to yield good agreement with experiment in cases of surface, internal, and amplitude dependent damping

Toward a Universal Model of Damping--Modified Coulomb Friction

Relationship between internal viscous damping and stiffness of concrete material and structure

This study focused on the frequency-dependent damping properties of recycled aggregate concrete (RAC) and provided new insights into the damping mechanism of RAC. Cyclic compressive loading...

Frequency-Dependent Damping Properties of Recycled Aggregate Concrete

Study on nonlinear damping behavior of damaged recycled aggregate concrete beams

This paper presents an investigation on the effects of recycled coarse aggregate (RCA) replacement ratio and recycled rubber particle (RRP) size on the hysteretic energy and damping variation of recycled aggregate concrete (RAC) under various cyclic compression loadings. The hysteretic energy and damping of RAC v. s. The same stress amplitude and strain amplitude were compared and analyzed, and the mechanism of hysteretic energy and damping variation of RAC were discussed. The results show that the hysteretic energy of RAC increases with increasing RCA replacement ratio and RRP size under the same stress amplitude, while an opposite phenomenon is observed under the same strain amplitude. The incorporated RRPs and RCAs improve the hysteretic energy and damping of RAC in the elastic stage under the same stress amplitude. The hysteretic energy and damping variation of RAC are closely related to the damage evolution and dynamic modulus degradation with increasing levels of applied loading. The hysteretic energy follows a power function of the applied stress amplitude or strain amplitude, and the energy dissipation within the RAC defects is the main damping mechanism of RAC. The damping variation of RAC under the same stress amplitude is mainly affected by the hysteretic energy as the stress evolves; however, the damping variation under the same strain amplitude is primarily impacted by the dynamic modulus as the strain evolves.

Hysteretic energy and damping variation of recycled aggregate concrete with different cyclic compression loading levels

The invention discloses a testing method for damping after concrete materials are damaged. The method comprises the following steps of pouring concrete test pieces and carrying out standard curing for28 days; vertically fixing the bottoms of the prepared concrete test pieces in a test device, mounting protection box bodies on the concrete test pieces, and applying axial load; and demounting the protection box bodies, applying excitation force to the upper ends of the concrete test pieces, recording acceleration signals through utilization of acceleration sensors set on the concrete test pieces, carrying out testing analysis on power performance of the concrete test pieces, and computing a damping ratio. According to the method, the load can be applied when the damping is tested, differentconcrete materials and damaged concrete material damping performance are tested, a test result is accurate and credible, the method can be used for comparing damping characteristics of the concrete materials in different service phases, and the method has remarkable engineering value and scientific value.

Chunhui Wang

Papers

Relationship between internal viscous damping and stiffness of concrete material and structure

Frequency-Dependent Damping Properties of Recycled Aggregate Concrete

Study on nonlinear damping behavior of damaged recycled aggregate concrete beams

Hysteretic energy and damping variation of recycled aggregate concrete with different cyclic compression loading levels

Testing method for damping after concrete materials are damaged