How to Add a Deck to a RISAFloor Model
July 12, 2012

How to Add a Deck to a RISAFloor Model

RISAFloor has some default decks provided for you when you open the program in the Deck Definitions spreadsheet. You can use one of these decks or you can create your own by going to the bottom of the spreadsheet and press ENTER.

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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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