Estimation Of Ultimate Strength For Steel Plates Damaged By Cyclic Loading

Steel structures under seismic action, a typical damage is local instability.Local buckling reduces the ultimate strength of steel. In order to restore the loadcarrying capacity, deformation and failure of the structure be repaired. Structuraldeformation and failure to estimate the residual strength of the structure, andthus provide the basis for the repair work.In this paper,Ultimate strength of damaged steel plate is investigated byusing elasto-plastic finite element method. Analytical model is simply supportedat all edges and introduced initial deflection and residual stress. We defined“damage deflection” as the out-of-plate deflection at the plate center after thecyclic loading. The relationship between the damage deflection and ultimatestrength of damage plate is discussed from analyzed results. The decreasing ofultimate strength depends on the only damage deflection when the damagedeflection exceeds the limit value that is decided by width-thickness parameter.In the case that the damage deflection is smaller than the limit value, theultimate strength is equal to the undamaged steel plate strength. From these results, the estimation procedure of ultimate strength of damaged steel plate isproposed. With proposed procedure, it is easily possible to estimate the strengthof damaged steel plate by the width-to-thickness parameter and damagedeflection.