Appendix 6 of the ANSI/AISC 360-10 Specification provides methods for assessing the required stiffness and strength for basic bracing of columns and of beams. Substantial evidence exists showing that the Appendix 6 equations provide an accurate characterization of the stability bracing requirements, particularly when various refinements from the AISC Commentary are employed. Nevertheless, the development of these equations is based largely on elastic stability theory and various practical approximations are invoked to make the equations useful for design. Some of the important approximations relate to the handling of member inelasticity as well as the influence of member continuity across brace point locations. To the knowledge of the author, no comprehensive studies have been conducted to date to evaluate the specific nature of these approximations. Furthermore, the current Appendix 6 provisions do not recognize the benefits of combined lateral and torsional bracing. Limited prior research studies have shown substantial reduction in the demands on the individual bracing components by using them in combination. This thesis presents a methodical and comprehensive study of basic beam bracing behavior via refined FEA test simulation. Various point (nodal) lateral, shear panel (relative) lateral, point torsional, combined point lateral and point torsional, and combined shear panel lateral and point torsional bracing cases are studied for representative beams subjected to uniform bending. Detailed comparisons to the current Appendix 6 rules are provided, where applicable, and recommendations for improvements are forwarded. Specific questions addressed in this research are: • What is the effect of inelasticity on the bracing response and requirements? • What is the influence of member continuity across the brace points on the bracing response and requirements? • What are the benefits of combined torsional and lateral bracing when the lateral bracing is placed on the compression flange versus when it is placed on the tension flange.

Master of Science / Department of Architectural Engineering and Construction Science / Bill Zhang / Vibration has been a consideration in many types of structures, and as the advancement of technology has allowed steel and concrete sections to become lighter, vibration has become more of a consideration in the design of structures. This report focuses on occupant induced vibration of steel framed floors due to running as the vibration source. The history of vibration analysis and criteria in structures is discussed. However, lack of research and experimentation on running as the source of vibration exists; therefore, the history section focuses on walking as the source of vibration. The current design criteria for vibration of steel framed floors in the United States of America is the American Institute of Steel Construction (AISC) Design Guide 11: Vibrations of Steel Framed Structural Systems Due to Human Activity. This design guide discusses vibration due to walking, running, and rhythmic activities as well as gives design criteria for sensitive occupancies and sensitive equipment. In order to apply the Design Guide 11 analysis procedure for running as the source of vibration, the Kansas State University Chester E. Peters Recreation Complex is used as a case study. The recreation complex includes a 1/5-mile running track that is supported by a composite steel framed floor. Based on the Design Guide 11 criterion, the running track is deemed acceptable. Lastly, this report discusses remedial procedures in the case of annoying floor vibration specific to floors that have running as a source of vibration. In addition, areas of further research are suggested where running is a source of vibration on steel framed floors.

This paper focuses on illustrating the effectiveness of the new material model, 𝜏𝐵𝑇𝑅 in comparison with the Specifications for Structural Steel Buildings (2016) material model, 𝜏𝐴𝐼𝑆𝐶 , against a detailed finite element model to determine the accuracy of modeling the inelastic behavior of steel W-Shapes. A total of seven steel columns were analyzed, using a W8x31 section, and eleven benchmark frames to compare the performance of the two material models. An ultimate strength study was conducted using the following slenderness ratios, L/r, of 40, 60, 80, 100, 120, 160, and 200 and oriented such that minor-axis bending occurs. The benchmark frames were modeled under a limit load analysis to illustrate the magnitude of stiffness reduction considering both major and minor-axis bending. Lateral displacements were recorded and compared for the eleven frames up to the collapse condition. Additional information is provided discussing the capabilities of the two material models and their performance when compared to a detailed finite element model. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection