Computational & Analytical Modeling of the Collapse Resistance of Steel Columns.

steel columns;local damage;seismic design;Civil and Environmental Engineering;Engineering;Civil Engineering

Fogarty, Julie ElizabethLynch, Jerome P. ;

University of Michigan

关键词: steel columns;    local damage;    seismic design;    Civil and Environmental Engineering;    Engineering;    Civil Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/113357/jefogart_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Understanding steel column behavior under extreme events is necessary for the safe and efficient design of steel structures. To improve this understanding, steel columns that have experienced local flange damage as well as those subjected to a combined axial and lateral loading scheme are investigated. Educational tools to better visualize steel column behavior are also presented. Given the widespread use of steel structural systems, results from this work have the potential to save many lives through improved structural design and better evaluation of structural integrity following an extreme event.Locally flange damaged steel columns are investigated analytically and computationally to quantify the effect of damage extent and location on column load carrying capacity. Results from these studies indicate that the compressive strength of steel columns can be severely reduced following local flange damage. A simplified design model and empirical equation are presented for use by practicing engineers as a means of approximating this reduced capacity.To address extreme seismic events, steel columns subjected to a combined axial and cyclic lateral loading scenario are studied using detailed finite element models. Regression analysis indicates that the current seismic design guidelines are not conservative. A design aide is proposed for highly ductile members using the statistically significant parameters.Additional combined axial and monotonic lateral loading studies using analytical and computational models are undertaken to better understand column behavior. An increase in local buckling due to increased axial loads or lateral drift not only interrupts the load path, but also weakens the boundary conditions. While the interruption due to local buckling alone is insignificant, the additional alteration of the boundary conditions can lead to lower axial capacities than expected. Modified effective length factors are proposed as a means of approximating the axial capacity of a column under this loading scenario. The ability to communicate and increase understanding of steel column behavior is addressed using newly developed virtual reality models that are deployed in the undergraduate steel design course. Quantitative and qualitative evaluation of the impact of these models on improving student understanding of buckled shapes is also presented.