August 27, 2020
VIDEO: Creating Custom Shapes in RISA-3D
Learn how to build custom steel and concrete shapes using RISASection and then import them into RISA-3D to incorporate them in analysis and design.
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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Learn how to build custom steel and concrete shapes using RISASection and then import them into RISA-3D to incorporate them in analysis and design.
When determining the Depth of Compression Block value of ‘a’ in a Masonry Wall design based on the equation a = (As * fy)/(0.8 * fm * b) in a RISA-3D model, it is possible to see a small variance in the program results versus a traditional hand calculation using this typical equation. The reason...
Modeling and analyzing structures for dynamic conditions is essential to understanding how a structure will react to loading such as wind and seismic. These analysis types can include simple free vibration analysis as well as more advanced response spectra and time history analysis. RISA-3D is...
In structural engineering, a modal analysis uses the overall mass and stiffness of a structure to find the various periods at which the structure will naturally resonate, along with the frequencies of vibration of the structure. In RISA-3D, the modal analysis is a prerequisite to the response...
Color contours and gradients can be very helpful to visualize the forces/stresses of plates and wall panels. But did you know there are other design tools that can be helpful in analyzing and understanding these contours? The family of Internal Force Summation Tools (IFST, IFST Wall and IFST Slab)...
RISA-3D can be used to model the effects of rotating machinery on their support structures. In the model below, we have a structure which is to support a piece of rotating machinery.
A question that we are asked from time to time in technical support is “why is my required force higher than what is reported in my force diagrams”. For instance, in the detail report below we can see that the maximum moment about the member’s weak axis is 28.9 k-ft. However, the required weak axis...
The release of the RISA-Tekla Link v10 introduces compatibility with Tekla Structures V2020. This update of the link includes the following features as well as other enhancements:
Industrial Structures are generally designed to fulfill a specific function within an industry or to support equipment, raw materials, or communication lines. These structures present complex challenges to structural engineers due to their narrow scope, size and requirement for efficiency in...
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