NCEER-89-0033 | 9/27/1989 | 106 pages
TOC: The table of contents is provided.
Keywords: Reinforced Concrete Structures, Damage Evaluation Model, Risk Assessment Studies, Inelastic Design Spectra, Existing Structures, and New Structures.
Abstract: A new normalized damage index for evaluation of structural damage of reinforced concrete was developed based on the relation of demand and capacity. The proposed formulation combines two sources of damage: permanent deformation and strength deterioration due to cyclic loading during dynamic events. The new damage model is first verified for single components. Based on the compressive strains in the core concrete, tensile strains in the transverse hoops and a good photographic record of the component during stages of testing, damage limit states for serviceability, repairability/irrepairability and collapse are identified and correlated with the damage model. A global damage index is also proposed based on individual member damage indices, which uses a weighting scheme that assigns importance as a function of gravity loading. Finally, an inelastic design spectra is recommended for code development wherein the relationship between the natural period of the structure and the response reduction factor is quantified in terms of incurred structural damage.