Novel, Highly Efficient Spanning Structural Trusses

A structural truss is one of the most efficient structural systems that transfer external loads through the axial resistance of its members. Structural spanning trusses have been used in various applications, from equipment supports to spanning floors or bridges. Optimal cross-sectional areas of members in a statically determinate truss can be calculated using the virtual work method and the LaGrange multiplier optimization technique. As discussed in the recently published ASCE Report, there is no single truss type that performs the best in all conditions. Also, the report has shown a way to compare different types of trusses in a wide design domain. The best-performing truss depends on multiple parameters, such as span-to-depth ratio, location of supports and loading, and slenderness of the truss members. An observation that Warren, Pratt, and Howe are trusses that essentially stem from a similar topology suggests that relocation of the unloaded nodes of a Warren truss may provide new efficiencies. In general, the optimized location of the unloaded nodes tends to converge to have a shorter compression member. As a result of the moving node, the required material quantity can be reduced even above 5% in practical applications.