October 30, 2020

Cold Formed Steel Wall Design Now Available

Cold-formed steel framing is a durable, reliable and cost-effective option for low-rise and mid-rise building projects. With the release of RISA-3D Version 19 and RISAFloor Version 15, cold formed steel (CFS) walls are now available for analysis and design. Walls that have been designated as lateral in RISAFloor will be transferred into RISA-3D when utilizing the Director feature.

Currently, CFS walls are only available when the AISI S100-16: ASD or LRFD code is selected from the Model Settings.

To draw CFS walls in RISA-3D, simply choose CFS from the Wall Material dropdown menu in the Properties Panel.

The design for the CFS walls will follow the criteria assigned in the Design Rules. The Wall Design Rules may be modified through the Wall Design Rules spreadsheet, or through the Wall Definition Editor by selecting the ellipsis to the right of the Design Rule in the Properties Panel.

CFS wall sheathing material options include Wood Structural sheathing, Steel Sheet sheathing, Gypsum board panels and Fiberboard. The sheathing material may be selected in the Wall Design Rules spreadsheet or within the Wall Panel Definition Editor. The program will design the optimal sheathing size based on the thickness requirements and shear demands.

The Segmented method is used for the analysis and design of the CFS walls. This means that portions of the wall above and below openings will be disregarded and only full height regions of the CFS wall will be considered to resist lateral shear forces and their corresponding overturning moments. Additionally, hold down and strap forces will be provided for full height regions.

Comprehensive design results for CFS walls are available in the expandable detail reports. View force diagrams and governing equations for each wall panel region. Each limit state can be expanded for design verification.

Chord forces for each region are reported in the Cross Section Detailing. These forces shall be used for the design of hold-downs for the wall panel.

For more information on CFS wall design and integration with RISAFloor, check out the video below.

Tags: RISA-3D, Walls, RISAFloor, New, v15, v19, Cold Formed Steel

October 30, 2020 | RISA-3D, RISAFloor, RISA-2D, Concrete, RISAFoundation, New, Updated Shear Contribution for Concrete (Vc) per A, Interaction of Shear Forces Acting Along Orthogona, RISAFloorES

Concrete Design according to ACI 318-19 Now Available

The new ACI 318-19 concrete code has been implemented into RISA-3D v19, RISAFloor v15, RISAFoundation v13 and RISA-2D v19. To select this code for your design, simply choose them from the Codes tab of the Model Settings: A summary of the major changes that have been incorporated include: The expansion of permissible applications for high-strength reinforcement. As a result, many requirements for strength and ductility have been adjusted. Some of these requirements include but are not limited to the the strength reduction factor, the maximum/minimum flexural reinforcement limit, and the axial compressive strength of columns. The calculation for the shear contribution of concrete (Vc) in accordance with Table 22.5.5.1.The calculation of Vc must consider axial load (Nu) and/or the flexural reinforcement ratio (ρw) when Av > Av,min. A new size effect modification factor (λs) must be considered when Av < Av,min. The consideration for the interaction of biaxial shear forces in members when Vu/ΦVn > 0.5 in both orthogonal directions. New equations for the allowable compressive strength of concrete piles based on the type of pile. Additional slab reinforcement requirements at critical sections for punching shear. Refer to the articles linked below for more information on effects that ACI 318-19…

December 8, 2017 | RISAFoundation, New, Soil

Soil Properties in RISAFoundation

With Pile Design in RISAFoundation, you have the ability to define the default soil properties for the entire model. But also the Soil Definitions spreadsheet gives you control over all the soil property layers in one location. The default soil definition will be used the whole model except where another soil region is drawn in the model (shown below with the Default? checkbox). Note: If you only have one soil profile for your entire model, you don’t need to draw a soil region. The program will use the default for the soil region. The Soil Definitions spreadsheet has the option to input the depth properties used for axial pile design of concrete, hot rolled, and wood piles. To access the Soil Depth Properties spreadsheet, just click on the Depth Properties cell and click on the red arrow. The Soil Depth Properties spreadsheet will allow the user to enter the soil layer properties. You can refer to the project site geotechnical report to find the soil layer properties. In special cases where the building site has different soil properties across the site, the user can draw a soil region through the Draw Soil Regions tool: The Soil Definition Editor allows the…

September 11, 2017 | Seismic, RISA-3D, New, Analysis, Wind

Improved Drift Reporting

RISA-3D v15 now includes automatic drift definitions for diaphragms as well as simplified story drift application. The reported drift results have been updated as well, and are now much more relevant for today’s codes. Drift results will report results in red text when seismic drift exceeds the limits specified in ASCE-7 2010. In addition, deflection amplification due to 2nd order effects is now reported, and will appear in red text whenever it exceeds the AISC 14th edition requirements. Drift Definitions Spreadsheet The new Drift Definitions spreadsheet defines where the drift calculations will be performed. If the model contains diaphragms, the joints connected to that diaphragm will automatically be considered in drift calculations. In addition, Drift calculations may be performed at specific elevations (where diaphragms don’t exist) merely by specifying these elevations in the spreadsheet. The user may also specify individual joints to be used in drift calculation. This can be helpful for points that don’t line up well from floor to floor or don’t behave the same as other joints at that elevation. For example: Inclined columns Columns that span multiple stories Center of Mass locations What is Story Drift and Drift Ratio? The Drift at a given level is…