View Important Policies and System Requirements for this course.

This webinar was co-sponsored by ASCE's Structural Engineering Institute (SEI) and ASCE Continuing Education

Instructor:  Allen Adams P.E., S.E., M.ASCE

Course Length: 1.5 Hours

Purpose and Background

The behavior of a building structure in response to an earthquake or wind is heavily dependent upon the nature, extent, and stiffness of the floor and roof diaphragms. This involves the distribution of the lateral forces to the lateral force resisting elements such as moment frames, braced frames or shear walls. It is important that the building model used in the analysis and design of a building accurately, or adequately, capture the effects of these diaphragms. This course discusses the types of diaphragms identified by the Building Codes and commonly considered by engineers, Building Code requirements pertaining to those diaphragms, and practical recommendations on the appropriate modeling of those diaphragms in analysis software. Understanding of structural analysis and design is necessary for attending this webinar and should be considered as an advance course.

Primary Discussion Topics

• Introduction of diaphragm types: Rigid, Semi-Rigid, Flexible
• Code requirements pertaining to diaphragms: IBC and ASCE 7
• Modeling of diaphragms in analysis software
• Sensitivity of the analytical results to the various diaphragm modeling options
• Recommendations for selection of diaphragm types in analysis

Learning Outcomes

Upon completion of this course, you will be able to:

• Determine the differences between rigid, semi-rigid, and flexible diaphragms and their impacts on analytical results
• Become aware of building code requirements pertaining to diaphragms, particularly the differences between the requirements of IBC 2012 and ASCE 7-10
• Discover the relationship between the type of diaphragm in the analytical model and the way the lateral loads need to be determined and modeled
• Identify the sensitivity of analytical results to the type of diaphragm used in the analytical model
• Find out about the sensitivity of analytical results to the various components of semi-rigid diaphragm model, including mesh size and material stiffness
• Make appropriate decisions on diaphragm and load modeling, balancing the needed level of accuracy with the business demands of speed and simplicity

Webinar Benefits

• Understand the differences of the diaphragm definitions and requirements between IBC 2012 and ASCE 7-10
• Learn the sensitivity of the analysis results to the type of diaphragm and the precision of the diaphragm properties in the analytical model
• Examine the procedures for calculating and specifying semi-rigid diaphragm material and stiffness properties
• Understand the relationship between the diaphragm type and the proper modeling of wind and seismic loads in the analytical model
• Discover how to avoid unconservative design errors due to inappropriate modeling of diaphragms in the analytical model
• Avoid the expense and loss of productivity due to selection of a diaphragm model that is more complicated than is necessary to get appropriate design results
• Recognize potential errors and limitations of each type of diaphragm model

Assessment of Learning Outcomes

Students' achievement of the learning outcomes will be assessed via a short post-assessment (true-false, multiple choice and fill in the blank questions).

Intended Audience

• Structural and civil engineers involved in the design of buildings
• City, county and state plan checkers and plan reviewers
• Webinar prerequisite - an understanding of structural analysis and design

Webinar Outline

• Introduction of diaphragm types
• Code requirements related to diaphragm analysis
• Modeling of diaphragms in analysis software
• Mechanisms for distribution of loads to frames
• Modeling of diaphragm loads
• Sensitivity of the analytical results

How to Earn your CEUs/PDHs and Receive Your Certificate of Completion

To receive your certificate of completion, you will need to complete a short on-line post-test and receive a passing score of 70% or higher within 1 year of purchasing the course.

How do I convert CEUs to PDHs?

1.0 CEU = 10 PDHs [Example: 0.1 CEU = 1 PDH]