May 14, 2014
Trim and Extend in RISAFloor
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. The Dynamics Scenario Imagine we’re tasked with evaluating the stability of a cantilevered pedestrian bridge that spans over a city street. The bridge is connected to a building on one side and features decorative panels and a lightweight canopy. The concern? Wind gusts and foot traffic could cause the bridge to vibrate. Our goal is to understand its dynamic properties—natural frequencies and mode shapes—and assess whether it can handle these dynamic forces without compromising structural stability. We start by setting up dynamic mass for each load case: Canopy Load: Applied uniformly along the length of the bridge to account for wind effects. Pedestrian Load: Simulated at intervals along the span to reflect walking traffic. Decorative Panels: Modeled with specific weights on each side. Once mass and stiffness are set, RISA-3D enables us to simulate how the structure behaves dynamically, revealing which parts might be sensitive to specific frequencies or forces. Running the Eigensolution Analysis In RISA-3D, we use an eigensolution to identify: Natural Frequencies (intrinsic vibration rates…
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Print reports can contain spreadsheet information, graphic views, detail reports for specific members and load combinations, and external images such as hand calculations, title pages, etc. When in a model view, you will notice a button with an image of a camera on it in the toolbar:
Need to first know how to model a slab on grade? See our Slabs on Grade article to learn how to model slabs on grade:
RISAFoundation was originally created as mat slab design software, but with some tweaks in the latest version (v6.0) it is now useful for slab on grade design as well. To get a design for slab on grade simply draw a slab element which has the appropriate thickness:
Now you have the ability to add in your customized company logo to a report.
RISA-3D and RISA-2D come with a default list of existing moving load patterns. These are listed in the Moving Loads Library which can be viewed by clicking on the Moving Load Patterns button in the Advanced tab.
In modeling what would be a rather difficult geometric structure, by using the Templates database in RISA-3D, a geodesic dome can be constructed rather quickly and easily.
Use RISASection to find the properties of built-up steel sections, then model beams using the same section properties in RISA-3D and get full code-checks using AISC 360. This webinar will teach you how to use RISASection quickly and easily to determine complex section properties.
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