Evaluation of Strength Reduction Factor for Concentrically Braced Frames Based on Nonlinear Single Degree-of-Freedom Systems

<p>Strength Reduction Factor (R-Factor), often referred to as Response Modification Factor, is commonly used in the design of lateral force resisting systems under seismic loading. R-Factors allow for a reduction in design base shear demands, leading to more economical designs. The reduction of strength is remedied with ductile behavior in members of proper detailing. Modern seismic codes and provisions recommend R-Factors for many types of lateral force resisting systems. However these factors are independent of the system fundamental frequency and many other important system properties, resulting in factors that may result in an unfavorable seismic response. To evaluate the validity of prescribed R-Factors an extensive analytical parameter study was conducted using a FEM single degree-of-freedom Concentrically Braced Frame (CBF) under incremental dynamic analysis over a suite of ground motions. Parameters of the study include brace slenderness, fundamental frequency, increment resolution, FEM mesh refinement, effects of leaning columns, and effects of low-cycle fatigue. Results suggest that R-Factor can vary drastically for CBF systems with differing properties.</p>

Name thesis:degree_name

MS in Civil and Environmental Engineering

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Year dc:date.available

2016

Author dc:creator

• Slein, Ryan Michael

Contributors dc:contributor

• Bing Qu

• Strength Reduction Factor
• Ductility
• Concentrically Braced Frame Response
• Low-cycle Fatigue
• Slenderness
• Structural Engineering

Identifier

10.15368/theses.2016.5

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-2688