Connections placement optimization approach toward new prefabricated building systems

Abstract

This article presents an approach for optimizing the location of connections in prefabricated building frame systems. This approach, referred to as the optimum “Connections-Placement-Approach (CPA)”, improves the present design decisions associated with the determination of the location of the connections. It is well suited for automated prefabricated construction, which in particular has the capability of producing unique, precise concrete segments. Within an algorithm and for building geometry, as an example, the article illustrates how the features of the connections and forces amounts can locate the connections, optimally. The optimization algorithm, 1-Considers the mechanical properties of the joints and defines corresponding Coefficients (C) for each type of the forces in each joint. 2-Takes all kinds of forces exerted to a joint such as shear, axial load and bending moments into account, 3-Calculates a proposed semi-weighted-function as the indicator (WIF) and 4-It Compares the indicators (WIF) and locates the connections as far as possible from the points of accumulation of related forces. The approach is through four examples discussed, and the algorithmic approach step-wise described, in which the results of a building’s numerical analysis are interfaced with a coding package. Although the main discussion assumes pre-cast-concrete design, it can be applied to timber, steel or other structures as well, which are assessed and assembled before their construction. It is found out that the load capacity of a connection has a dominant effect in assigning its optimal location, which leads to a new extensible optimized pre-cast configuration.