The same structures are often needed in several projects, such as the purlin with columns and braces in this example. The dimensions can be changed directly in RFEM or RSTAB by shifting the nodes.
The function, which is also known as shifting, allows you to calculate critical load factors beyond a user‑defined initial value. Determination of the critical load factors is usually done from the smallest to the greatest critical load factor.
In order to consider inaccuracies regarding the position of masses in a response spectrum analysis, standards for seismic design specify rules that have to be applied in both the simplified and multi-modal response spectrum analyses. These rules describe the following general procedure: The story mass must be shifted by a certain eccentricity, which results in a torsional moment.
In the case of very small distances between isolines, the labels often overlap, which makes the result documentation difficult. As of RFEM version 5.06, you can select a shifted arrangement of the isoline labels in the Display Properties dialog box. By selecting the "Show values shifted" option, you can easily avoid overlapping the result values in many cases.
In order to represent the stiffness of the entire structure correctly, you can consider shear coupling between the ceiling and the downstand beam using the line release. This way, you can define a spring constant, thus avoiding the replacement system by using coupling members. The spring constant results from the shift modulus of the fastener, which can be determined according to EN 1995-1-1 or ANSI/AWC NDS, for example.
From time to time, gaps may occur in the numbering of load cases when working on a model. You can use the "Renumber" → "Shift" function under "Tools" to simply shift the load cases and close the gaps.
Not only do RF-/STEEL EC3 and RF-/TIMBER Pro perform cross-section designs and stability analyses, they allow you to perform serviceability limit state designs. For this, it is possible to relate the deformation to the undeformed initial system or to shifted members ends.