Design and Performance of Connections for Pultruded Frame Structures

Abstract

The design and performance of connections for framed structures built from commercially produced pultruded wide-flange shapes is discussed. These connec tions, known in the civil engineering community as beam-to-column connections, can be found in most building frames. The response of a framed structure is influenced by both the rotational stiffness and the ultimate strength of its connections. This article describes an experimental and analytical investigation of the behavior of pultruded beam-to-column connections. Four full-size connections were designed and tested. Connection elements consisted of pultruded angle and Tee Flange shapes and gusset plates which were "bolted" with pultruded threaded rods and compression molded nuts or "bonded" with an epoxy adhesive. Conventional clip angle type connections and a novel prototype connection that utilized both Tee Flange shapes and tubular stiffeners were tested. Moment-rotation and ultimate strength data are reported as well as detailed descriptions of the failure modes of each of the connections. Comparisons are made between the different connections. Results of an analysis of a full-size pultruded frame are presented to demonstrate the significance of the connection rotational stiffnesses on the frame's response. The performance of the prototype connection was found to be far superior to the conventional clip angle connec tion. Recommendations are made for the design of connections for pultruded frame struc tures.