Strength Evaluation of End-Plate Connections Using Stiffness Reduction Factor

The cross-sections of the Pre-engineered Buildings (PEBs) are efficiently proportioned in accordance with the external forces compared to the conventional steel structures which enhances their usability. PEBs are generally made for long spans, therefore their elements cannot be constructed/fabricated at once which creates situations where the connections between elements or even in many cases, within the parts of one element, become unavoidable. The connections regions of the elements of PEBs become weaker because of the thin section designs with bolts and holes, compared to the other regions of the elements. When the connection strength decreases it results reduction in stiffness, leading to earlier total collapse of the buildings with limited deformability than anticipation. In this paper, the extended and flush type end-plate connections for PEB elements were designed and experimentally tested under monotonic loading conditions in order to evaluate the failure mechanisms and potential reduction in stiffness. Later, a detailed finite element analysis was performed using ABQUS, to comprehend the test observations and carry-out a parametric study. The effect of various connection parameters was investigated in details and the stiffness reduction factor values in accordance with the stiffness degradation for each connection, were evaluated for the practical design purpose.