Optimizing the structural performance of oval hollow structural sections

点击翻译按钮获取中文摘要

Ankor Engineering Ltd. is a Canadian company specializing in the design, manufacture and installation of building façade access and safety systems. One such system utilizes telescoping and single-length outrigger booms that cantilever up to 30 metres from the side of a building to support equipment and maintenance workers. Steel structures have traditionally made extensive use of off-the-shelf beams and columns. Within the past 20 years, tubular sections (in Canada, referred to as Hollow Structural Sections, or HSS) have become very popular. These sections have very high torsional rigidity, and so make a very economic choice for columns in many building applications. Ankor Engineering Ltd. has developed a hybrid section that can be categorized as an oval HSS (OHSS). It starts with a basic rectangular HSS section, but includes bends in the plates to reduce the potential for local buckling in the web. The advantage of the Ankor design over other HSS members such as elliptical sections is that is can be manufactured at a much lower cost. In addition, the Ankor design maintains a minimum radius in the corners of 3t, where t is the thickness of the HSS member. This ensures no microscopic stress cracks and minimizes brittle-type failures during galvanizing. Ankor Engineering Ltd. has successfully used OHSS in outrigger booms for a number of years. However, there is very little engineering guidance in the literature regarding these shapes, and Ankor Engineering Ltd. has had to rely on limited in-house testing and modelling to guide their design. As a result, they have been forced to take a very conservative approach, which obviously hurts their ability to optimize the costs of their product. This research will focus on understanding the structural performance of OHSS cantilever beams. A combination of physical testing and numerical modeling will be used to understand how to safely and economically design OHSS structures.