Tips & Tricks

December 29, 2025

What’s New for IBC 2024 in RISA: A Closer Look

With RISA’s latest release of RISA-3D v23.0.1, we’re continuing to expand support for IBC 2024, helping engineers stay aligned with the latest building code requirements as adoption accelerates across the U.S.—including federally funded projects. This release builds on v23.0.0 ASCE 7-22 enhancements and adds key material design updates that move RISA further into full IBC 2024 compliance. New Material Design Updates Supporting IBC 2024 The upcoming release introduces several important design code updates referenced by IBC 2024, including: Steel Seismic design per AISC 341-22 Prequalified connections per AISC 358-22 Continued support for AISC 360-22 (16th Edition) steel design Ongoing updates to the hot-rolled shape database, including compatibility with both 15th and 16th Edition steel manuals These updates support modern seismic detailing requirements and ensure consistency with current steel industry standards. Masonry Masonry design per TMS 402-22, aligning with the latest strength and serviceability provisions adopted by IBC 2024. Key updates include: Revisions to shear design equations, including clarified definitions of shear area as outlined in Table 4.4.5, improving consistency and transparency in shear capacity calculations. Updated strength reduction factors for flexure and combined flexure + axial. Unlike previous editions that used a fixed ϕ-factor of 0.9, TMS 402-22 introduces tension-controlled,…

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How to Model a Column within a Wall in RISA-3D
August 9, 2012

How to Model a Column within a Wall in RISA-3D

While RISA-3D does not currently have pilaster design, there are still plenty of situations where you would want to have a column embedded within a wall. The idea behind this is that the column handles the gravity loads for any beams which frame into it, while the wall handles lateral loads. No...

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How to Apply Hydrostatic Loads to Circular Tanks in RISA-3D
June 7, 2012

How to Apply Hydrostatic Loads to Circular Tanks in RISA-3D

RISA-3D v10 now has the ability to quickly and easily apply hydrostatic loads to circular tanks using the Cylinder Generator. This generator can be found by clicking the Templates button and choosing the Cylinder - Plates/Members option.

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Why Don’t My Response Spectra Reactions Satisfy Statics?
April 3, 2012

Why Don’t My Response Spectra Reactions Satisfy Statics?

The applied loads in a response spectrum analysis (RSA) are the applied masses times the accelerations in the response spectra. Each mode of vibration produces its own set of joint reactions. The reactions for each mode obey statics as shown in the portal frame example shown below: Response...

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How Do I Resolve a P-Delta Instability?
February 23, 2012

How Do I Resolve a P-Delta Instability?

Investigating P-Delta instabilities in RISA-3D (or RISA-2D) can be difficult. The first step is usually to solve the model without the P-Delta effect included to see if there are any obvious deflection problems that could cause issues with a P-Delta analysis. But, what can be done when this doesn’t...

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How to Apply a Rigid Diaphragm in RISA-3D
February 13, 2012

How to Apply a Rigid Diaphragm in RISA-3D

In RISA-3D, rigid diaphragms can be added using the Diaphragm spreadsheet. Just enter the node label and then choose the horizontal plane. Internally, all rigid diaphragms are membrane diaphragms that tie all of the nodes within the diaphragm plane together for both translation and rotation, but...

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How do Plates and Walls interact with each other?
February 6, 2012

How do Plates and Walls interact with each other?

Below is a model of a concrete flat slab (represented by a plate) which is bearing on two columns and a skewed wall. As we know from plate meshing we will obviously have to submesh this slab in order to get accurate results. However if we do an ordinary submesh (as shown below) the plates will not...

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Why is Plate Meshing Important?
February 2, 2012

Why is Plate Meshing Important?

Aside from the topic of plate connectivity, the concept of plate meshing is equally important to the analysis of structures using finite elements (plates).

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