Please note that this lesson has two parts. As such, there will be only one quiz and assignment which can be found at the end of the 3-term vs. 4-term Deflection Equation Example video.

Introduction

The video explains the difference between the non-linear 4-term deflection equation from SDPWS Figure C 4.3.2-1 and the  and the simplified 3-term linear approximation now available in Shearwalls Program.  The 3-term equation, adapted from the American SDPWS standard, combines the shear and nail slip components into a single shear term, making calculations linear.

While both equations yield the same deflection at 100% design capacity, the 3-term equation estimates higher deflections at lower loads and helps avoid convergence issues in the Shearwalls Program, particularly when distributing load between wood sheathing and gypsum wallboard. This simplification improves the accuracy and reliability of load sharing in shear wall design calculations.

Learning Outcomes

By the end of this lesson, you will be able to:

• Differentiate between the 3-term and 4-term deflection equations used in shearwall analysis, including their assumptions and applications.
• Explain the benefits of using the simplified 3-term deflection equation in structural design, particularly in program applications.
• Analyze how load distribution varies when using the 3-term versus the 4-term deflection equation, especially in walls with multiple sheathing materials.
• Evaluate the impact of equation selection on deflection accuracy and the ability to model real-world shearwall behavior in engineering design program.

Instructional Video

Video Run Time: 04:08 minutes

Introduction

The focus in this video is on flexible diaphragm distribution and how it is applied within the software. Building on the previous discussion of flexible versus rigid diaphragms, the video outlines when flexible diaphragm assumptions are permitted under U.S. codes, such as ASCE 7-16 for light-frame wood structures. Viewers learn how to toggle between flexible, rigid, and worst-case distribution options in the software and observe how loads are assigned based on tributary areas during flexible diaphragm analysis. While the program does not calculate diaphragm flexibility directly, it highlights how users can assess this manually using deflection criteria.

Learning Outcomes

By the end of this lesson, you will be able to:

• Explain the difference between flexible and rigid diaphragm distribution and their effects on shearwall design.
• Identify when flexible diaphragm distribution is permitted based on U.S. building codes, including ASCE 7-16.
• Demonstrate how to apply and analyze flexible diaphragm settings using the Shearwalls Program.
• Evaluate diaphragm flexibility by comparing manually calculated diaphragm deflection with shearwall story drift.

Instructional Video

Video Run Time: 02:35 minutes

This video utilizes one project file and it is available for download below.

Please note that this lesson has three parts. As such, there will be only one quiz and assignment which can be found at the end of the Creating and Moving Walls video.

Introduction

The Shearwalls Program is an advanced software tool for designing shearwalls and analyzing lateral loads in multi-storey wood-frame buildings. It supports both regular and some irregular building shapes, offering flexible design options with or without hold-downs. Key features include CAD import, customizable roof shapes and wall openings, and the ability to visualize loads through elevation views. With support for up to six stories, it streamlines structural analysis using both flexible and rigid diaphragm methods.

Learning Outcomes

By the end of this lesson, you will be able to:

• Describe the core functionalities of the Shearwalls Program for designing and analyzing multi-storey wood-frame structures.
• Differentiate between flexible and rigid diaphragm analysis methods within the context of shearwall design.
• Utilize software features such as CAD imports, elevation views, and customizable openings to develop accurate structural models.
• Apply the software to design shearwalls for buildings up to six stories, considering various roof shapes and building geometries.

Instructional Video

Video Run Time: 10:23 minutes