Evaluation of damage index for RC frames with irregular geometrical shape subjected to blast loads

الملخص EN

The present research focuses on studying the effect of architectural shape ofreinforced concrete frames resulting from irregularity of geometrical shape ofbuilding frame.

The reinforced concrete Frame, consisting of eight storey andthree bays, was designed by the American Code ACI-14.

SAP2000 (V.20)software was used for the purposes of design, analysis, of the structural responsefor behavior elasto-plastic under the effect of blast loading, through a number ofvariables, including the maximum displacement and plastic deformations at thetip of structure, number and status of plastic hinges formed, and damage index.

The interaction diagram between axial force and bending moment was adoptedas a yield surface to undergo the transition from elastic to plastic behavior for thecolumns, while the design yield moment was defined as a yield criterion forbeams.

The accumulated plasticity (Plastic hinge) at the ends of structuralelement was used to simulate the elasto-plastic behavior.

Irregularity andunsymmetrical form of frame structure have a significant effect on increasing thedeformations and plastic displacements in the elements more than 40% andincreasing the damage index in structure more than 18% , that is calculated on thebasis of dissipated energy by plastic deformations.

The distance between centersof Mass (C.

M.

) and Stiffness (C.

S.

) significantly affects the response of structure, where the plastic deformations of structural elements are in the least damage zonein case of convergence between two centers, compared to other cases ofheterogeneity irregularity of geometrical shape of structure that results indiverging of these centers.