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...
In this video, you’ll learn how to investigate your RISA-3D model for P-Delta divergence errors. This type of error is common in general structural analysis software and has two major causes: a model that is unstable or a model that is too flexible. For this investigation, two separate steel frame...
“Why am I receiving a P-Delta instability error when I run my DL + LL load combination? I don’t see this error when I run my lateral load only combination.”
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...
When a model is loaded, it deflects. The deflections in the members of the model may induce secondary moments due to the fact that the ends of the member may no longer be vertical in the deflected position. These secondary effects for members can be accurately approximated through the use of...
