Tips & Tricks
October 28, 2025
Why Maximum Moment Graphs Differ from Flexural Demand in RISA-3D
When the Graphs Don’t Match: Understanding the Controlling Case A common question from users is why the maximum moment shown in the Detail Report graphs doesn’t match the required flexural moment reported in the design results. At first glance, this difference can be confusing — but it comes down to how RISA determines the controlling condition for design. Each member design is based on the governing load combination and the controlling location along the member where the combined effects of bending and axial forces produce the highest demand-to-capacity ratio (DCR). The graphs, on the other hand, show the pure bending moment diagram, which does not include these combined effects. To fully understand the calculation behind the flexural demand (and shear), expand the Applied Loading section of the Detail Report. There you’ll see how RISA combines: Bending + Axial forces for flexural checks Shear + Torsion forces for shear checks By reviewing both the governing load combination (Gov LC) and the location of the controlling results within the expanded sections, you can pinpoint exactly where and why your member design is governed by interaction effects rather than just the maximum moment value from the diagram. When Torsion is Involved: Considering Warping…
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June 17, 2025
Understanding Plate and Member Interaction in RISA
When modeling plate elements alongside member elements in RISA, users may notice that member forces—such as bending moments or axial loads—are lower than expected. This behavior is often the result of how loads are shared between plates and members based on their relative stiffness. If the...
May 22, 2025
How RISA Powers Manufacturing Facility Design from Top to Bottom
Case Study: Designing for Strength at Every Level When a Midwest engineering firm was tasked with designing a 120,000-square-foot manufacturing facility, they knew the challenge wasn’t just about steel and concrete—it was about integration. The structure needed to support overhead cranes, custom...
November 19, 2024
How to Run a Basic Dynamic Eigensolution in RISA-3D?
Welcome to a high-level walkthrough of dynamic analysis in RISA-3D! This guide introduces essential aspects of modeling dynamics, focusing on natural frequencies, mode shapes, and the impact of dynamic behavior on structural integrity.
October 25, 2024
Tips for Solving a Slow Solution in RISA-3D
Is your RISA-3D software solution running slower than you expected? There are a few things you can do during your model set up in order to make your model more efficient and reduce the solution time. RISA has compiled a list of our most common tips for solving a slow solution in RISA-3D.
October 22, 2024
How to View Step Results for Moving Loads in RISA-3D?
In RISA-3D, moving load results are generated by simulating a load that moves across a structure in defined increments. These loads are often used for designing bridges, cranes, or other structures where dynamic loads shift across the structure over time. Moving loads are complex because they...
October 8, 2024
How to Troubleshoot Large Deflections in RISA-3D?
Deflection is a key tool for verifying whether your model was built correctly in RISA-3D. After solving, you can view the deflected shape to confirm if the deflections are within the expected range. If you notice abnormal deflections, use the following steps to troubleshoot the issue.
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