Design optimization of long-span king-post trusses

With a unique arch and tie feature, king-post trusses can be built economically and efficiently and quickly for long-span roof structures. It has gained much popularity since its advent in early 1990s. The optimal design of the king-post truss system involves not only weight of the material but also factors such as fabrication, transportation and erection. This paper presents a design optimization method for long-span king-post roof truss systems. Through two example trusses built in North America, the main parameters affecting the cost of the truss system are studied thoroughly. Design guidelines, which aim to obtain a cost-effective design, are given for the determination of the depths of the overall truss and arched top truss. The result of the study is of great assistance to practicing engineers.