Investigation the Effect of Strengthening Various Subpanels in the SPSPs with Two Rectangular Openings

In the present research, behavior of SPSPs with two rectangular openings and effect of strengthening different subpanels with various stiffener arrangements is investigated. In the next step, to investigate the effect of changing opening width on the trend of degradation shear stiffness and strength of the panel, the opening width is changed. In the third step, to study the effect of changing opening height on the behavior of the whole panel, the opening height is changed. Based on the results obtained, it is observed that for SPSPs with constant plate thickness and opening dimensions, strengthening various subpanels with different stiffener arrangements has no effect on the values of shear stiffness of the panel, and only the shear strength of the panel is changed. In the case of panels with constant opening dimensions and plate thickness and stiffened corner panels (height of subpanels equal to opening height), changing the number of horizontal and vertical stiffeners to stiff corner panels with different stiffener arrangements, has no effect on shear stiffness. Only the shear strength is changed in these models. For SPSPs with constant opening dimensions and constant plate thickness and different stiffener arrangements to stiff corner panels, by increasing number of both horizontal and vertical stiffeners, no changes on the shear stiffness is created, and its effect on the value of shear strength is negligible. However, using L3T3 and L1T0 stiffener arrangements result in obtaining maximum and minimum values of shear strength, respectively. In addition, the effect of changing opening width in the SPSPs with constant opening height and also the effect of changing opening height in the SPSPs with constant opening width on the values of shear strength and stiffness of the specimens is investigated.