Remove joint of seismic force acting points in risa 3d

Optimizing Seismic Design with RISAFloor: Removing Joint of Seismic Force Acting Points in RISA 3D

====================================================================================

Introduction

----------

RISAFloor is a powerful structural analysis and design software that helps engineers optimize the performance of steel structures under various loads, including seismic forces. One critical aspect of seismic design involves managing joint locations where these forces act within a structure's frame. In this article, we will explore how to effectively remove or adjust such joints in RISA 3D while ensuring compliance with structural integrity standards.

Why Remove Joint Points?

----------------------

When designing steel structures for seismic resistance using RISAFloor and RISA-3D, it is essential to carefully manage the locations where seismic forces act. In particular, joint points that concentrate these loads can significantly impact a structure's overall stability and ductility under extreme lateral or vertical movements.

In many cases, removing redundant or unnecessary joints not only simplifies the structural design process but also contributes to cost savings by reducing material requirements for steel framing elements like columns, beams, bracing members etc., among others. However, doing so requires careful consideration of potential consequences on global stiffness behavior as well local detailing requirements at interfaces between different components.

Step-by-Step Guide in RISAFloor

-----------------------------

1. Open your 3D or Lateral model in RISAFloor.

2. Select all the joints that you wish to remove by holding down Ctrl (Windows) or Command + A on Mac and then clicking on each joint with your mouse while keeping Shift key pressed.

Alternatively, if you have applied loads directly to specific points within these selected elements through manual input via 'Properties' dialog box found under 'Beam/Column' tabs > Loads tab > Load Type dropdown list where applicable select 'Point load', proceed as follows:

a. Right-click anywhere inside active view area then choose 'Delete Objects'.

b. Confirm the deletion prompt when prompted.

Post-Removal Steps

--------------

After removing unnecessary joint points, it is crucial to ensure that your model remains structurally sound and meets all relevant seismic design codes. Here are some essential post-processing tasks:

1. Recalculate member forces and stresses using 'Analysis > Run' or equivalent commands depending on your RISAFloor version.

2. Verify that the updated analysis results comply with both local building codes (e.g., AS/NZS 2005 for Australia/New Zealand) as well international standards like Eurocode 8.

-------

In conclusion, judiciously managing joint locations where seismic forces act is critical to optimizing steel structure design under extreme loads. By following the step-by-step guide provided above and carefully considering potential implications on structural performance post-removal of redundant elements using RISAFloor alongside corresponding updates in associated models like RISA 3D, engineers can significantly improve their ability to create safe yet cost-effective solutions that meet or exceed rigorous seismic design standards.

References

---------

1. 'RISAFloor User's Manual,' Version , CSI Inc., 'Publication Date'.

Remove joint of seismic force acting points in risa 3d