A Relationship between Modulus and Damping Provides for Simple,Unified Modeling of Both

摘要

The shear stress - shear strain behavior of soil is characterized by a hysteresis loop. The geometry of the loop over one cycle of loading can be used to establish a simple equation that relates secant shear modulus to shear damping. The equation applies to values of modulus and damping obtained at all values of shear strain. No other information is needed. Two simple hyperbolic expressions, with only two coefficients, accurately describe both the shear modulus degradation and damping increase with shear strain. The equations include reference strain to allow the results to be relatively independent of confining stress. They are obtained with an optimization program in a spreadsheet. Results from resonant column tests on sand, silt and clay soils demonstrate their efficacy for determining minimum and maximum values of damping.