A ground structure method to optimize topology and sizing of steel frame structures to minimize material, fabrication and erection cost
Abstract/Contents
- Abstract
- Engineers are often challenged to design steel structures that are safe, economical, constructible. This design process involves specifying each of the following three aspects of the structure: (i) topology, which concerns the number and connectivity of members; (ii) shape, which pertains to the location of structural joints; and (iii) sizing, which involves defining member cross-sections. This thesis presents a method to optimize topology and sizing of steel frame structures to minimize total installed cost while meeting defined safety and constructability requirements. Based on the Ground Structure Method (GSM), the proposed approach begins with an array of nodes that are interconnected with a dense mesh of linear members which have undergone a geometric check to ensure feasibility of fabrication and erection. Each member in the structure is then sized in an iterative process considering the applied forces and discrete set of section types provided. The sizing process ensures that the members are capable of bearing the applied loads and therefore result in a safe structure. Next, each connection in the structure is detailed based on the joint forces and incoming member sizes. The material quantities from the detailed structure are then used to estimate the cost of each member, including connections, based on unit rates that are intended to be provided by the steel fabricator, erector and material supplier. Finally, members in the structure are ranked according to their stress to cost ratio. The topology optimization process functions by systematically removing members in the structure which have a relatively low stress per unit cost until the converged solutions is found. The proposed Cost-Driven Deterministic Ground Structure Method (CDD-GSM) is applied to a typical two-dimensional building braced frame structure in order to demonstrate the method and compare its performance to a typical weight-based GSM approach. While being 18% heavier, CDD-GSM solution is approximately 8% cheaper than the weight-optimal design. These results highlight the limitations of existing weight-based approaches and demonstrates the importance of an accurate cost-based objective function in order to improve the practicality and effectiveness of topology and sizing optimization methods.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Havelia, Pratyush |
|---|---|
| Associated with | Stanford University, Department of Civil and Environmental Engineering. |
| Advisor | Fischer, Martin, 1960 July 11- |
| Advisor | Flager, Forest, 1978- |
| Thesis advisor | Fischer, Martin, 1960 July 11- |
| Thesis advisor | Flager, Forest, 1978- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Pratyush Havelia. |
|---|---|
| Note | Submitted to the Department of Civil and Environmental Engineering. |
| Thesis | Thesis (Engineering)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Pratyush Havelia
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...