الفهرس 
Chapter (1) introductionOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
The objective of this thesis is to introduce an overall concept about the application of torsion on cold-formed steel sections. Usually, the torsional moment could not occur on any section directly, but it results from the non-coincidence of the longitudinal axis of any applied load and the imaginary longitudinal axis of shear center. Therefore, the first part presents a proposal for new forming that can be executed for a cold-formed section -an open thin-walled section- to compel both the loading longitudinal axis and shear center longitudinal axis to coincide. Then, A sequence technique is developed to determine all properties of any arbitrary thin-walled section especially the torsional one, to be considered while studying the effect of torsional moment applied on a cold-formed section. Afterward, general formulas for all common cases that would exist in real situations, are introduced. These relations can determine the values of yield torques generated in any open thin-walled sections at the critical points using the theory of Von-mises. Finally, experimental works were implemented on different sections using two setups of the rig. Therefore, a manual device was implemented using simple components with a perfectly accurate measuring tool. Then, a complete numerical analysis was introduced using ANSYS Workbench-V15 to be compared with the experimental results. Moreover, a comprehensive parametric study was developed using the most effective factors as well as an optimization algorithm is presented for the most common sections to introduce the most optimal ratios for these sections subjected to direct torque.