The Investigation On Cold-Formed Thin-Walled Steel Beam-Column Joints Of Connections With Bolt-Plate

Cold-formed steel sections are lightweight materials, suitable for building construction owing to their high structural performance and durability. They are wildly used as secondary members, such as purling in roofs, joists of medium span in floors ,studs in wall panel, storage racking in warehouse, and hoarding structure in construction site. Since 1990, there has been a growing trend to use cold-formed steel sections as primary structural members in building construction, such as low to medium rise residential house and portal frame of modest span.In building construction, cold-formed steel sections are usually bolted to hot rolled steel plate or sections to form simple and moment connections. However, despite their simplicity, simple connections between cold-formed steel sections have received relatively little attention. In order to assess the structural performance of cold-formed steel members with bolted moment connections for practical application, an experiment investigation was undertaken by the College of Civil Engineering at ChongQing University in 2005. Two lipped C sections back-to-back with interconnections are used as beam and column members. The 2 groups of connection configurations with gusset pates of hot rolled steel to form bolted moment connections to accommodate members in practical orientation. One group of the connections used the gusset plate without chamfers, but another group connection of the plate with chamfers. Only the web of lipped C sections are connected with bolts; the section flanges are not connected for ease of construction. It is acknowledged that neither rigid connections nor full moment resistance at the connections may be achieved easily in practical connection configuration.In order to provide proven data for design development , a number of finite element model with three-dimensional solid elements was established to investigate the performance of cold-formed steel bolted-plate connections in details. The investigation takes the forms of the following parts:Part I: Using FE soft ANSYS to build numeral models, then contrast the performance between the experimental tests and FE models; (total 10 models)Part II: Building the 1st groups of FE models to assess the performance of connections which have the different bolt pitch; (total 11 models)Part III: Building the 2nd groups of FE models to assess the performance of connections which have the different thickness of the hot rolled gusset plate; (total 7 models)Part IV: The 3rd group of FE models have the gusset plates with chamfers. Then contrast the performance of the connections between the 1st group (the gusset plate without chamfers) and the 3rd;Part V: Recommendation of design rules supplementary to existing design guides for bolted moment connections among cold formed steel members.