March 25, 2020

Seismic Design of Steel Structures in RISA-3D

RISA-3D includes the ability to design steel structures for seismic provisions found in AISC 341 and AISC 358 including moment frames and braced frames. For more information, review the video below.

Tags: Seismic, RISA-3D, New, Steel

March 30, 2011 | Seismic, RISA-3D, New

How to Apply the Seismic Provisions in RISA-3D

The Seismic Provisions in RISA-3D will check various design and code check requirements according to the AISC design provisions (AISC 360-2005, AISC 341-2005, AISC 358-2009). Seismic Design Rules can be applied to any member in the model, just follow the steps listed below. Step 1: Define the Seismic Design Rules. The Seismic Design Rules spreadsheet can be found on your Data Entry Toolbar or in the Spreadsheet menu. To learn more about seismic design rules, read What Are the Seismic Design Rules in RISA-3D. Link: What are the Seismic Design Rules in RISA-3D? Step 2: Assign the Seismic Design Rules to your member by going to the Properties panel and expanding the Design Properties menu. Step 3: Set the Seismic Overstrength (W) factors in Settings on the Seismic tab. Step 4: Create the Overstrength Load Combinations Now you are ready to run your model and review your results…

March 28, 2019 | Seismic, RISA-3D, New

Assigning Seismic Loads in RISA-3D

RISA-3D has two ways of automatically generating seismic-related Basic Load Categories (BLCs) which can be later referenced in the Load Combinations (LCs): 1. Creating seismic BLCs (ELX, ELZ, etc) from the Seismic Load Generator 2. Creating seismic BLCs (SX, SZ, etc) from Response Spectra Analysis In addition to the automatic generated seismic loads, users can always draw any loads and add them to seismic load consideration. How to generate seismic loads from the seismic load generators are further discussed here: How to create seismic loads from response spectra analysis is further discussed here: Once the seismic-related Basic Load Categories (BLCs) are created, they can be used in analysis by referencing them in the Load Combinations (LCs). RISA-3D also has Load Combination (LC) Generators that will generator seismic-related combinations based on selected codes. How to use the LC generator is further discussed here: The seismic load categories (ELX, ELZ, etc.) generated from the Seismic Load Generator can also be viewed visually from the load display. The seismic load categories (SX, SZ, etc.) generated from Response Spectra Analysis cannot be viewed visually, but users can check the total base reactions from the joint reaction spreadsheet as a reflection for the applied lateral…

March 3, 2011 | Seismic, RISA-3D, Loads, New

How to Use Seismic Factors in Load Combinations in RISA-3D

RISA-3D now has the ability to define the seismic parameters Rho, Omega and SDS directly into load combinations. If you open the Basic Load Cases spreadsheet and click into the BLC column, the dialog offers the ability to add these values in to factor the load. Here we will see that Rho and Omega can only be used if the Load Category Code is set to a seismic option. Sds can only be used if Dead Load is selected. Once you apply this factor it is automatically taken into account without the use of the Factor column in the Load Combinations spreadsheet. The actual values for these factors are defined in the Seismic tab of Global Parameters. Rho is specified in section 12.3.4 of the ASCE 7-16. Omega is specified in Table 12.2-1. SDS is used for the vertical portion of seismic load and is typically multiplied by 0.2*DL in Section 12.4 combinations…