This past July 19, our structural designer Mathieu Côté had the opportunity to present his Master's thesis from MIT's Topology Optimization and Advanced Design Engineering Lab during the 59th edition of the IASS - International Association for Shell and Spatial Structures - annual symposium held in Boston from July 16 to 20.
The symposium brings together leading designers and researchers working in the fields of structural engineering and architecture from around the world and features 10 plenary talks, 460 technical papers, with nearly 600 attendees from 40 countries.
The symposium theme for 2018, Creativity in Structural Design, celebrates work in the built environment that pushes beyond the status quo and synthesizes across disciplines to solve important problems of today and the future. Empowered by recent advances in computation, materials, and fabrication, creative structural design is expanding possibilities for shell and spatial structures.
Mathieu's thesis is titled Shear wall layout optimization of dynamically loaded three-dimensional tall building structures and was supervised by Josephine Carstensen who co-led the track on Topology Optimization for Structural Design during the event.
Here's a description of Mathieu's work:
Deciding on the appropriate layout of shear walls and the thickness of each member is an iterative process that is time consuming and often leads to suboptimal results. Every time the stiffness of the building is modified, the structural designer must ensure deflection and inter-story drift limits are respected followed by flexural, shear and torsional strength checks for each shear wall. A computational optimization framework has the potential to limit the design time, but most importantly to identify layout configurations with lower costs, weight, and embodied carbon and with increased consideration for architectural constraints. Additionally, an optimization framework can provide a strong tool for early stage, pre-conceptual idea exploration and thereby lead to an increased collaboration between architects and engineers. This thesis presents an approach that allows the structural designer to design the shear wall layout of a three-dimensional structure using a linearized modal analysis and a modified genetic algorithm. The presented design scheme uses a ground structure approach as it allows for architectural constraints to be embedded in the design. The objective is defined as a cost function that incorporates material cost and constructability. The proposed framework is used to design the shear wall layout of a building under wind and seismic load cases and is compared to the design obtained with conventional methods.
Photo: MIT's Kresge Auditorium designed by Eero Saarinen during the IASS symposium | Source: IASS2018 Instagram