While international guidelines generally suggest using fixed damping values ranging from \(5\%\) to \(10\%\) in concrete gravity dams, depending on the intensity of ground motion, this study uncovers that actual damping ratios are significantly lower than the recommended minimum of \(5\%\) . By incorporating stress-dependent damping ratios, the research reveals intricate relationships among material damping, structural response, and crack initiation. Damping ratios in linear analyses consistently remain below \(1\%\) , while in cases with nonlinear behavior of mass concrete, they reach approximately \(2\%\) and the resulted crack profiles within the dam body is sensitive to the damping mechanism. In addition, the tensile stress increases about \(20\%\) with the inclusion of spatially varying damping, while there is no considerable change in the compressive stress level. These findings underscore the substantial sensitivity of dams to variations in damping, emphasizing the need for more dynamic and adaptive damping considerations. Notably, the results are consistent with experimental data from concrete gravity dams and laboratory concrete specimens, further confirming that actual damping levels are lower than those currently prescribed by guidelines.
