Design support system for multi-storey timber structures

Abstract: The research presented in this thesis is intended to improve the building process for multi-storey timber houses by reducing the risk of information loss between architects and structural engineers and by improving the possibilities for the structural engineers to optimise the structure with respect to production cost. This is reached by developing and implementing a conceptual model for a design support system for multi-storey timber structures that is capable of handling the information transfer between the architects and the structural engineers in a standardized manner and by providing a method that is capable of finding optimally directed solutions for the structure with respect to production cost. Different functionality requirements for a design support system for multi-storey timber structures has been formulated by performing interviews with architects, studies of tenant inquiries and an analysis of the structural design process for the stabilising structure in a multi-storey timber house. These requirements have been used as a base for the development of the conceptual model for the design support system and in the implementation of the model. The implementation is performed in two phases. In the first phase a program has been written in C++ that, given an architectural design, finds an optimally directed design of the stabilising structure in multi-storey timber houses with respect to production cost. The program also creates a detailed building product model that for example is possible to use in manufacturing of the stabilising structure. The production cost calculations are based on object-oriented a cost calculation method in order to reflect detailed changes in the configuration of the building product model. In the following phase the architectural design is linked to the structural calculation by using IFC, which is one of the standards for building product models. The implemented conceptual model has been verified in different steps. A built multi-storey timber house project, WinterCity 2000, has been used as a test case together with some smaller examples in order to verify the force distribution between the walls and to judge the quality of the optimally directed building product model calculated by the design support system. Furthermore, single walls has been used to verify the load resistance and that the building product model is instantiated in a correct way. The object- oriented cost calculation method has been calibrated and verified in a study together with a multi-storey timber house manufacturer. The most important and surprising result is that it is possible to lower the production cost in the factory for the shear walls in Winter City 2000 by up to 10% if the walls should be manufactured according to the proposed configuration. The results further shows that it is possible to use the implemented method for finding optimally directed solutions, PGSL, in very large search spaces and within reasonable computational time. Finally the results also show that it is possible to use an object-oriented cost calculation method to calculate the production cost for a multi-storey timber structure in a rationale way.