KB 000751 | Determining Shear Areas

Using an example of a steel fiber-reinforced concrete slab, this article describes how the use of different integration methods and of a different number of integration points affects the calculation result.

When it comes to wind loads on building type structures as per ASCE 7, numerous resources can be found to supplement design standards and aid engineers with this lateral load application. However, engineers may find it more difficult to find similar resources for wind loading on non-building type structures. This article will examine the steps to calculate and apply wind loads as per ASCE 7-22 on a circular reinforced concrete tank with a dome roof.

In order to correctly design a downstand beam or a T-beam in RFEM 6 using the Concrete Design add-on, it is essential to determine the flange widths for the rib members. This article describes the input options for a two-span beam and the calculation of the flange dimensions according to EN 1992-1-1.

For a response spectrum analysis of building models, you can display the sensitivity coefficients for the horizontal directions by story.

These key figures allow you to interpret the sensitivity to stability effects.

The modal relevance factor (MRF) can help you to assess to which extent specific elements participate in a specific mode shape. The calculation is based on the relative elastic deformation energy of each individual member.

The MRF can be used to distinguish between local and global mode shapes. If multiple individual members show significant MRF (for example, > 20%), the instability of the entire structure or a substructure is very likely. On the other hand, if the sum of all MRFs for an eigenmode is around 100%, a local stability phenomenon (for example, buckling of a single bar) can be expected.

Furthermore, the MRF can be used to determine critical loads and equivalent buckling lengths of certain members (for example, for stability design). Mode shapes for which a specific member has small MRF values (for example, < 20%) can be neglected in this context.

The MRF is displayed by mode shape in the result table under Stability Analysis → Results by Members → Effective Lengths and Critical Loads.

You can use the "Plate Cut" component to cut plates (for example, gusset plates, fin plates, and so on). There are various cutting methods available:

• Plane: The cut is performed on the closest surface to the reference plate.
• Surface: Only the intersecting parts of plates are cut.
• Bounding Box: The outermost dimension consisting of width and height is cut out of the plate as a rectangle.
• Convex Envelope: The outer hull of the cross-section is used for the plate cut. If there are fillets at the corner nodes of the cross-section, the cut is adapted to them.