Numerical Assessment Approach for Flange to Flange Double Tee Connections Subject to Vehicular Loading

Abstract A PCI funded research effort was conducted to assess the fatigue resistance of welded flange to flange connections used in double tee precast concrete construction. The connection consists of steel connectors embedded in the edge of the precast flange welded to each other through the use of a steel jumper plate and fillet welds. Variations on this connection have been used for over 50 years with success. The strength limit states of this connection have been explored in detail but the stresses in the connection at service load levels are not well understood. The research effort was conducted specifically to quantify the fatigue resistance of these connections to the repeated loading typical of parking structure service demands. A two part series of articles are developed to summarize methods that can be used to accurately analyze and assess the fatigue life of these connections. This paper examines numerical methods that can be used to readily determine the state of stress in the weld under service loads using detailed 3D models of connector systems and shell element models of diaphragm systems. The ability to accurately determine the stresses in the weld can be combined with a vehicular load spectrum and a suitable fatigue life curve for the fillet weld detail to obtain a realistic assessment of the fatigue life of connections.