Risa Tips & Tricks: How to Use Our Structural Analysis Software

October 29, 2026

5 Frightening RISA-3D Modeling Errors That Can Haunt Your Results

Spooky season is here with ghastly ghosts, glowing jack-o’-lanterns, and wicked witches around every corner. While Halloween scares can be fun, unexpected surprises in a structural model are a different story. This spooky season, keep an eye out for a few frighteningly common modeling issues in RISA-3D. Catching these modeling concerns early can help you create models that are a treat to analyze, not a trick. 1. Locked Nodes Does it ever feel like there’s a ghost in your model? You run your analysis and discover a LOCKED reaction in the results. Don’t be scared, these reactions are not supernatural. They are created by RISA-3D when the model is not adequately supported for a specific degree of freedom. Locked nodes provide temporary restraint to help stabilize the model during analysis, but they should not be treated as the final solution. Because these added restraints do not report the load removed from the model, they can obscure the intended load path. Investigate and resolve the underlying instability so you can confirm that loads are transferring through the structure as expected. For a closer look at common sources of RISA-3D instability warnings and ways to troubleshoot LOCKED reactions, read The Ultimate Guide…

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Plates (2)

May 24, 2011

How to Apply a Tapered Load to Plates in RISA-3D

It’s easy to apply tapered surface loads to plates in RISA-3D by stepping...

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December 13, 2010

Rebar Design using the Internal Force Summation Tool in RISA-3D

When you have a plate model for a slab or wall in RISA-3D, the Internal...

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July 29, 2010

How to Model a Semi-Rigid Diaphragm in Standalone RISA-3D

In standalone RISA-3D models (those not integrated from RISAFloor),...

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July 28, 2010

How Do Plates Connect to Members?

In order to understand the interaction between plates and members it is...

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June 14, 2010

How Do Plates Connect to Each Other?

To best understand how plates interact with each other you must first...

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