April 29, 2025

RISA Customer Portal for Educational Users

RISA Educational Program

RISA is proud to continue supporting the next generation of structural engineers by offering free access to our software through the RISA Educational Grant Program. For 2025, participating universities can access RISA software for $0 with a streamlined renewal and purchase process.

How to Enroll Users

There are two roles: Admin and Engineer. See the roles and permissions explain below.

Instructors or University Admins should be assigned to the Adming role in the RISA Customer Portal
Students should be assigned to the Engineer role in the RISA Customer Portal.

To learn more about the RISA Educational Program, visit the page below.

RISA Educational Program

Already a practicing engineer? Try RISA and see the difference for yourself.

Tags: New, Educational

December 21, 2010 | RISA-3D, Loads, New, Wood, Wind

How Can I Account For Continuous Tie Rods in RISA-3D Wood Walls?

Continuous tiedown systems are used to help resist overturning forces generated by lateral loads, and can be estimated in RISA-3D using the hold-down database and the strap forces. The Holddown Excel database is located in the RISA>Wood Schedules>HoldDowns folder and contains the parameters for the deflection calculations from the NDS 2015 Special Design Provisions for Wind and Seismic, Equation 4.3-1: In order to account for the uplift effects of the tiedown (rod elongation, bearing deformation, fastener slip, etc.) you need to change the change Δa. A good estimate of this value is listed below: P= Allowable Tension L= Length of the rod A= Area of the rod E= Stiffness of the rod It is important to note that this assumes a tied-off system which distributes loads at each level rather than a skipped story system. The manufacturers of the tiedowns require the tension forces at each floor level, and you can find the Strap Forces from Wall Detail Report. This can also be used to select the appropriate tiedown for the wall from the manufacturer’s charts listed under Allowable Tension Capacity based on the wood material…

February 15, 2022 | RISA-3D, New, Analysis, P-Delta

P-Delta Analysis using Geometric Nonlinear Stiffness in RISA-3D

RISA-3D continues to be at the cutting-edge of finite elements analysis software with the release of the Geometric Nonlinear Stiffness method for use during P-Delta analysis. Traditionally, RISA-3D considered P-Delta effects using a Standard Nodal Shear methodology which applies pseudo shear loads at the individual member nodes based on the axial load, lateral deflection and member geometry. To select this method, navigate to Model Settings > Advanced. When comparing the two methods, the standard Nodal Shear Method has been used for many years when considering P-Delta effects in RISA-3D. It is a widely utilized methodology in evaluating the secondary effect of the structure and proved to have great performance in most cases. However, due to the limitations of the method itself, it diverges quickly when axial loads approach the buckling loads. As a result, the P-Delta divergence could potentially occur prematurely for some structures. Another limitation of this method is that the loading is node based, and due to this, users would have to manually add internal nodes along the member to properly consider the P-small delta effect. For additional information on the Nodal Shear Method in RISA-3D and how it handles small P-Delta effects, visit our Online Help. Search…

December 16, 2010 | RISA-3D, New, Instability

How Should I Model Boundary Conditions for a Truss in RISA-3D?

When it comes to trusses in RISA-3D, boundary condition definitions (pin vs. roller) can make a huge difference. Let’s take an example of a typical roof truss. Note that a pin-pin boundary condition has been applied to the ends. First we must make sure to give the truss out of plane stability by setting this up as a 2D Model within RISA-3D. Then, after solving, you will find that this is not at all behaving like a truss. There are huge axial compression forces in the top chords, and there is no tension in the bottom chord. The reason is that the pin-pin boundary condition prevents the bottom chord from elongating. If it cannot elongate then there cannot be axial strain in the member. You will recall from your Mechanics of Materials class that if there is no strain there cannot be stress, and therefore there can be no axial tension in the bottom chord. The program works out statics the only way it knows how by using arching action with the top chords instead of looking at truss behavior. Now instead try a roller boundary condition on one end of the truss: Now the bottom chord is experiencing a…