# Experimental/Numerical Evaluation of Steel Trapezoidal Corrugated Infill Panels with an Opening
## 1 Introduction  
One type of lateral load resisting system used in the construction of new buildings or retrofitting of existing buildings is the steel shear wall. In this system, steel plates are attached to adjacent boundary elements (beams and columns). High stiffness, enhanced strength, great ductility, considerable energy absorption capability and stable hysteretic behavior are the specific characteristics of steel infill panels (SIPs) [1, 2, 3, 4]. The initial design procedure of SIPs has led to the use of thick or heavily stiffened steel plates to prevent elastic buckling. Thereafter, it was shown that the ultimate strength capacity of SIPs does not pertain to their buckling load, and considerable post-buckling strength was reported for thin SIPs. The in-plane shear load-resisting mechanism alters to a diagonal tension field at the buckling point of SIPs, and significant strength is obtained from the post-buckling tension field action. Moreover, the buckling strength of SIPs can increase using trapezoidal corrugated plates, which consist of the plane and inclined subpanels. The performance of corrugated steel infill panels (CSIPs) has been considered in past studies. [PERSON] and [PERSON] [5] presented formulas to determine the buckling load of CSIPs with vertical stiffeners. The accuracy of the proposed formulas was confirmed via the good agreement obtained between the results of these formulas and the finite element numerical results. [PERSON] et al. [6] studied the linear shear buckling analysis of simple and corrugated panels using numerical modeling. The numerical results were obtained close to those theoretical relations that consider a combination of global buckling and local buckling along with the shear yielding stress (interaction buckling). [PERSON] andYadollahi [7] considered the performance of simple and corrugated steel infill panels due to monotonic loading numerically. The models with corrugated panels had more ultimate bearing capacity, ductility and energy absorption capacity than the models with the simple panels. [PERSON] et al. [8] tested three specimens of one-story, single-bay CSIPs under cyclic loading. As reported, the stiffness, energy absorption capacity and ultimate strength of corrugated plates decreased with increasing the corrugation angle. In addition, the cyclic behavior of trapezoidal corrugated steel infill panels was studied experimentally by [PERSON] et al. [9]. This study reported that the initial stiffness, ductility and energy absorption capacity of corrugated models were 20%, 40% and 52% larger compared to the flat unstiffened model, respectively. Moreover, the performance of CSIPs under cyclic loading was considered in some other studies [10; 11; 12; 13; 14; 15; 16]. Meanwhile, the performance of multi-story SIPs was discussed in previous studies [17; 18; 19; 20; 21; 22]. Providing an opening in SIPs is sometimes necessary because of architectural restrictions. The introduction of an opening to steel panels could affect their performance. [PERSON] et al. [23] performed finite element analyses and utilized the FEM results to develop an artificial neural network to predict the behavior of SIIPs with an opening. [PERSON] and [PERSON] [24] investigated the performance of SIIPs with an opening. It was observed that the opening location affects the strength and stiffness degradation of unstiffened SIIPs with an opening. [PERSON] and [PERSON] [25] analyzed SIIPs with and without stiffened large rectangular openings. The results of their numerical analyses indicated that the geometry and location of stiffened openings do not directly influence the strength of SIIPs, and the main concern should be paid to the design of local boundary elements around the stiffened openings. [PERSON] and [PERSON] [26] tested three steel infill panel specimens under the influence of cyclic loading. It was found that the structural characteristics of the specimen with a central perforation and diagonal stiffeners are close to the characteristics of the solid unstiffened specimen.