Out-of-Plane Behavior of Lightweight Metallic Sandwich Panels

Sandwich panel systems offer many advantages over other conventional systems, which facilitate their use in several applications, including aerospace, naval, and transportation. The complexity and relatively high cost of sandwich panel system design and fabrication have limited its application in civil engineering applications. In accordance with North American standards for blast-resistant design of buildings, the dynamic behavior of a system can be predicted using its static resistance function obtained under equivalent uniform loading. The goal of this study was to quantify the quasi-static resistant function of novel cost effective lightweight cold-formed steel sandwich panels to be used in the context of blast-resistant structures. An analytical model has been introduced to predict the elastic characteristics of the proposed sandwich configurations and to assess the critical failure modes. In addition, an experimental program was performed involving eighteen sandwich panels under uniform quasi-static loading. Different configurations were investigated, including longitudinal and transverse corrugated core sandwich panels, using different deck profiles. The modes of failure experienced by the test panels were assessed and discussed and were found to be consistent with predicted failure modes. The quasi-static resistance functions for the proposed sandwich panel configurations were characterized in terms of yield loads and ultimate capacities and the corresponding displacement values. Analytically predicted values were compared to the experimental findings and found to be in a good agreement. The influence of sandwich panel core configuration and core sheet thickness on the behavior of the sandwich panels was examined, considering energy absorption and ductility. The results of the current study are expected to serve future development of cost-effective sandwich panels to be used as sacrificial cladding for the blast protection of structures.