Real structures have some level of damping which tends to reduce the vibratory response over time. The higher the damping, the faster the vibration will decay and the less likely vibrations will cause adverse affects. Damping is often defined as a fraction of critical damping, which is the level of damping that would be necessary to prevent oscillation altogether. In RAM Concept a constant damping ratio is used in the calculation of all modes. Typical damping ratios for concrete structures range from about 0.01 to 0.02 (1% to 2% of critical) for bare concrete floors, and 0.02 to 0.035 (2% to 3.5% of critical) for concrete floors with typical fit out.