Tapered Member Design Using AISC Design Guide 25
February 7, 2013

Tapered Member Design Using AISC Design Guide 25

RISA has now incorporated the tapered member design provisions from Steel Design Guide 25: Frame Design Using Web-Tapered Members written by Richard Kaehler, Don White and Yoon Kuk Kim. These code checking procedures are used whenever the AISC 13th or 14th edition steel codes are selected.

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Using Virtual Joist Girders in RISA-3D
October 4, 2012

Using Virtual Joist Girders in RISA-3D

The Steel Joist Institute (SJI) has developed a Virtual Joist Girder table which converts common joist sizes into equivalent wide flange beams for use in RISA-3D.

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How Can I Use a Wall for Shear Only (no Bearing) in RISA-3D?
September 13, 2012

How Can I Use a Wall for Shear Only (no Bearing) in RISA-3D?

Let’s consider the example of the frame shown below. Suppose there is a diaphragm present at the framing level, and that the wall shown is intended only to handle the lateral loads. In reality the columns will be in-line with the wall, and the cantilever beams will pass over the wall without...

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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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