The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-22 is categorized into two sections: member requirements and connection requirements.
Moment frame design according to AISC 341-16 is now possible in the Steel Design add-on of RFEM 6. The seismic design result is categorized into two sections: member requirements and connection requirements. This article covers the required strength of the connection. An example comparison of the results between RFEM and the AISC Seismic Design Manual [2] is presented.
For situations where no design is available, RF-/STEEL EC3 provides the option to neglect the respective internal forces. Examples of such situations are: bending and compression on angle sections, multi-axial bending for the design according to the General Method, torsion.
The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-16 is categorized into two sections: member requirements and connection requirements.
To evaluate whether it is also necessary to consider the second-order analysis in a dynamic calculation, the sensitivity coefficient of interstory drift θ is provided in EN 1998‑1, Sections 2.2.2 and 4.4.2.2. It can be calculated and analyzed using RFEM 6 and RSTAB 9. The coefficient θ is calculated as follows:$$\mathrm\theta\;=\;\frac{\displaystyle{\mathrm P}_\mathrm{tot}\;\cdot\;{\mathrm d}_\mathrm r}{{\mathrm V}_\mathrm{tot}\;\cdot\;\mathrm h}\;$$
The result window of the cross-section properties can be adjusted individually using the [Filter] button in the table menu bar. You can then activate or deactivate the individual cross-section parameters in the dialog box.
If intersections created in RFEM 4 are opened in an RFEM 5 file, the file management of intersections remains in the old format for compatibility reasons. Thus, the individual partial surfaces of the intersection can be activated or deactivated using only the "Integrated/Components" tab, all partial surfaces can only have the same thickness, and it is impossible to use the separate FE mesh refinement for the individual surface components.
For the ultimate limit state design, EN 1998‑1, Sections 2.2.2 and 4.4.2.2 require a calculation considering the second‑order theory (P‑Δ effect). This effect may be neglected only if the interstory drift sensitivity coefficient θ is less than 0.1.
If a section is not on a straight line but on a curved or angled line, this line has to be defined accordingly as a polyline or a curved line. You can define the section along a line using the "Create Section Numerically" function.
When modeling arc-shaped members, the problem shown in the figure may occur. It seems as if the member cross‑section is twisted or the load applied on the local z‑axis changes direction. How does this come about?
RFEM and RSTAB provide numerous interfaces with other programs for data exchange. In the respective programs, different names are often used for the same materials and cross-sections. Therefore, it is necessary to convert the material and cross‑section names in order for them to be recognized by the program after the data exchange.
Plate girder is an economical choice for long spans construction. I-section steel plate girder typically has a deep web to maximize its shear capacity and flange separation, yet thin web to minimize the self-weight. Due to its large height-to-thickness (h/tw) ratio, transverse stiffeners may be required to stiffen the slender web.
In order to design longitudinal reinforcement for the serviceability limit state, it is necessary to enable this function. This is possible in Window 1.1 General Data under the "Serviceability Limit State" tab. After you select the "Analytical..." method of checking, you can select the corresponding additional options in the section for determining the longitudinal reinforcement of the "Settings of Analytical Method of Serviceability Limit State Design" window.
RFEM 6 offers the Aluminum Design add-on for the design of aluminum members. This article shows how class 4 sections are designed according to Eurocode 9 in the program.
In the global selection of the printout report, you can select in the lower "Display" section whether you want to create a table of contents. The table of contents of the printout report usually requires too much space when displayed in one column.
By clicking "Options" → "Display Properties" → "Edit", you can change and save display settings for printout reports and your screen. For example, you can set individual colors for cross‑sections.
In addition to arcs and circles, SHAPE-THIN 8.xx allows you to model the following curved cross-section parts: ellipses, elliptical arcs, parabolas, hyperbolas, splines, NURBS (non-uniform rational B-Spline).
RF-/STEEL EC3 performs the classification, cross‑section designs, serviceability limit state designs, and fire resistance designs of members. For each design, the program shows a result table with the relevant values and classification numbers, including information regarding the respective standard clause. In order to identify the conjunction of various standards easily, there is a final design equation, including all terms, at the end of the table.