Lateral-Torsional Buckling (LTB) is a phenomenon that occurs when a beam or structural member is subjected to bending and the compression flange is not sufficiently supported laterally. This leads to a combination of lateral displacement and twisting. It is a critical consideration in the design of structural elements, especially in slender beams and girders.
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.
The Steel Joist Institute (SJI) previously developed Virtual Joist tables to estimate the section properties for Open Web Steel Joists. These Virtual Joist sections are characterized as equivalent wide-flange beams which closely approximate the joist chord area, effective moment of inertia, and weight. Virtual Joists are also available in the RFEM and RSTAB cross-section database.
RFEM 6 includes the Form-Finding add-on to determine the equilibrium shapes of surface models subjected to tension and members subjected to axial forces. Activate this add-on in the model's Base Data and use it to find the geometric position in which the prestress of lightweight structures is in equilibrium with the existing boundary conditions.
This article explains the use of surfaces with the Load Transfer stiffness type in RFEM 6. A practical example is also provided to demonstrate the application of self-weight, snow load, and wind load to a steel hall.
The additional loads from self‑weight are usually composed of several layers; for example, classic floor and ceiling layers in buildings, or road coatings for bridge constructions. When defining load definitions in RFEM and RSTAB, you can use the multi-layer load to define the individual layers with thickness and specific weight.
To carry out a structural analysis for a structural system according to the current standards, it is necessary not only to deal with the actions and resistances of structural components, but also with the combinations of these actions. Some of the most common actions in structural analysis are, for example, the permanently acting load case of self‑weight and the suddenly acting load cases of wind and snow.
To carry out a structural analysis for a structural system according to the current standards, it is necessary not only to deal with the actions and resistances of structural components, but also with the combinations of these actions. Some of the most common actions in structural analysis are, for example, the permanently acting load case of self‑weight and the suddenly acting load cases of wind and snow.
To carry out a structural analysis for a structural system according to the current standards, it is necessary not only to deal with the actions and resistances of structural components, but also with the combinations of these actions. The best-known actions in structural analysis are, for example, the permanently acting load case of self-weight and the suddenly acting load cases of wind and snow.
The Steel Joist Institute (SJI) previously developed Virtual Joist tables to estimate the section properties for Open Web Steel Joists. These Virtual Joist sections are characterized as equivalent wide-flange beams which closely approximate the joist chord area, effective moment of inertia, and weight. Virtual Joists are also available in the RFEM and RSTAB cross-section database.
Cable and tensile membrane structures are regarded as very slender and aesthetic building structures. The partly very complex double-curved shapes can be found using suitable form-finding algorithms. One possible solution is to search for the form via the equilibrium between the surface stress (provided prestress and an additional load such as self-weight, pressure, and so on) and the given boundary conditions.
If an aluminum member section is comprised of slender elements, failure can occur due to the local buckling of the flanges or webs before the member can reach full strength. In the add-on module RF-/ALUMINUM ADM, there are now three options for determining the nominal flexural strength for the limit state of local buckling, Mnlb, from Section F.3 in the 2015 Aluminum Design Manual. The three options include sections F.3.1 Weighted Average Method, F.3.2 Direct Strength Method, and F.3.3 Limiting Element Method.
The network-capable Project Manager controls the projects of all Dlubal Software applications in one central location. A table displays the important information for each model and corresponding file. Now, you can set dimension and weight units in the program options.
With RFEM 5.04, there are new options for the system analysis (critical load factors) of load cases and load combinations in the calculation parameters of the RF‑STABILITY add‑on module: ~ The load increment is not closed due to stability problems, but optionally also due to predetermined deformation limits. ~ The calculation method is applicable to all nonlinear calculations. ~ You can define an initial load (LC/CO) that is not increased (for example, self-weight). ~ The "Refinement of the last load increment" option provides an efficient option to determine the critical load factor as precisely as possible.
Diagonals of double angles are used for pipe bridge construction and for truss girders, among other things. They are usually subjected to tension, but it is necessary to transfer them in smaller compression forces with regard to the load application. In the case of slender diagonals in particular, you should also consider the bending due to self‑weight.