In the Steel Joints add-on, you have this option to consider the preloaded bolts in the calculation of all components.
You can easily activate the prestress using the check box in the bolt parameters, and it has an impact on the stress-strain analysis as well as the stiffness analysis.
Did you know? In the Design Supports, you can now define fully threaded screws as transversal compression stiffening elements for the "Compression Perpendicular to Grain" design. In this case, the pressing-in and buckling of the bolts is analyzed.
Moreover, the design shear resistance is checked in the plane of the screw tip. The angle of dispersal can be considered as linear under 45° or nonlinear (according to Bejtka, I. (2005). Verstärkung von Bauteilen aus holz mit vollgewindeschrauben. KIT Scientific Publishing.).
You know for sure that when connecting tension-loaded components with bolted connections, you need to consider the cross-section reduction due to the bolt holes in the ultimate limit state design. The structural analysis programs also have a solution for this. In the Aluminum Design add-on, you can enter a member local section reduction for this. Enter the reduction of the cross-section as an absolute value or as a percentage of the total area at all relevant locations.
Please note that when connecting tension-loaded components with bolted connections, you need to consider the cross-section reduction due to the bolt holes in the ultimate limit state design. But don't worry, this can be easily done in the program. In the Steel Design add-on, you can enter a member local section reduction – and that's it. You can enter the reduction of the cross-section as an absolute value or as a percentage of the total area at all relevant locations.
Graphical display of the connection geometry that is updated in parallel with the input
The Steel Joints Template included in the Add-on allows you to select from several connection types and, when selected, is applied to your model
In the Template, there are connections from 3 general categories: Rigid, Pinned, Truss
Automatic adaptation of the connection geometry, even if the members are subsequently edited, due to the relative relation of the components to each other
The program can also help you here. It determines the bolt forces on the basis of the calculation on the FE model and evaluates them automatically. You can perform the design checks of the bolt resistance for the failure cases tension, shear, hole bearing, and punching shear according to the standard. The program takes care of everything else in this step. It determines all the necessary coefficients and displays them clearly.
Do you want to perform weld design? The required stresses are also determined on the FE model in that case. Then, the Weld element is modeled as elastic-plastic shell element, where every FE element is checked for its internal forces. (Plasticity criteria is set to reflect failure acc. to AISC J2-4 and J2-5 (weld resistance check) and also J2-2 (base metal capacity check). The design can also be carried out with the partial safety factors according to the selected National Annex.
You can perform the plate design plasticall by comparing the existing plastic strain to the allowable plastic strain. By default this is set to 5% for the AISC 360 but can be specified through user-definition 5% according to EN 1993-1-5, Annex C, or again, user-defined specification.
Beam to Column joint category: connection possible as joint of the beam to the column flange as well as joint of the column to the girder flange
Beam to Beam joint category: design of beam joints as both moment-resisting end plate connections and rigid splice connections possible
Automatic export of model and load data possible from RFEM or RSTAB
Bolt sizes from M12 to M36 with strength grades 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, and 10.9 as long as the strength grades are available in the selected National Annex
Almost any bolt spacing and edge distances (a check of the allowable distances is performed)
Beam strengthening with tapers or stiffeners on the top and bottom surfaces
End plate connection with and without overlap
Connection with pure bending stress, pure normal force load (tension joint), or combination of normal force and bending possible
Calculation of connection stiffnesses and check if a hinged, semi-rigid, or rigid connection exists
End plate connection in a beam-column setup
Joint beams or columns can be stiffened with tapers on one side or with stiffeners to one or both sides
Wide range of possible stiffeners of the connection (for example, complete or incomplete web stiffeners)
Up to ten horizontal and four vertical bolts possible
Connected object possible as constant or tapered I-section
Designs:
Ultimate limit state of the connected beam (such as shear or tension resistance of the web plate)
Ultimate limit state of the end plate at the beam (for example, T-stub under tensile stress)
Ultimate limit state of the welds at the end plate
Ultimate limit state of the column in the area of the connection (for example, column flange under bending – T-stub)
All designs are performed according to EN 1993-1-8 and EN 1993-1-1
Moment-resisting end plate joint
Two or four vertical and up to 10 horizontal bolt rows
Joint beams can be stiffened with tapers on one side or with stiffeners to one or both sides
Connected objects are possible as constant or tapered I-sections
Designs:
Ultimate limit state of the connected beams (such as shear or tension resistance of the web plates)
Ultimate limit state of the end plates at the beam (for example, T-stub under tensile stress)
Ultimate limit state of the welds at the end plates
Ultimate limit state of the bolts in the end plate (combination of tension and shear)
Rigid splice plate connection
For the flange plate connection, up to ten bolt rows one behind the other possible
For the web plate connection, up to ten bolt rows possible each in vertical and horizontal directions
Material of the cleat can be different from the one of the beams
Designs:
Ultimate limit state of the joint beams (for example, net cross-section in the tension area)
Ultimate limit state of the cleat plates (for example, net cross-section under tensile stress)
Ultimate limit state of the single bolts and the bolt groups (for example, shear resistance design of the single bolt)
Design of moment resistant and simple joints of I-shaped rolled cross-sections according to Eurocode 3:
Moment-resisting end plate connections (type IH/IM)
Moment resistant purlin splices (PM type)
Simple joints with angle cleat and long angles (IW and IG types)
Simple joints with header end plates mounted either on web only or on web and flange (IS type)
Check of coped connections (IK) in combination with pinned end plates (IS) and angle connections (IW)
Automatic design of required joint with bolt sizes (all types)
Check of required thickness of load-bearing members for shear connections
Results of all required structural details such as appliances, hole arrangements, necessary extensions, a number of bolts, end plate dimensions, and welds
Results including stiffnesses Sj,ini of bending-resistant connections
Documentation of available loading and comparison with resistances
Results of design ratio for each individual joint
Automatic determination of governing internal forces for several load cases and connection nodes
The RF-/FRAME-JOINT Pro add-on module designs connections of structures calculated in RFEM/RSTAB. If there is no RFEM/RSTAB structure available, you can define the geometry and loading manually; for example, when checking external calculations, for example.
Designed nodes are usually imported from RFEM/RSTAB. The module recognizes all connected members automatically and assigns a connection type to them. Depending on the connection type, you can define further details of ribs, backing plates, web plates, bolts, welds, and hole spacing. As loads, you can select any load case, load combination or result combination in RFEM/RSTAB.
In the case of the "preliminary design" calculation mode, RF-/FRAME-JOINT Pro performs the first calculation step to suggest applicable layouts. After you select the relevant layout, the module displays all designs in detailed result tables and various graphics.
Design of knee joints, T-joints, cross joints, and continuous column connections with I-shaped sections
Import of geometry and load data from RFEM/RSTAB or manual specification of the connection (for example, for recalculation without an existing RFEM/RSTAB model)
Flush top connections or connections with bolt row in extension
Design of positive and negative frame joint moments
Various inclinations of right and left horizontal beams as well as application to frames of duopitch and monopitch roofs
Consideration of additional flanges in a horizontal beam, for example for tapered sections
Symmetrical and asymmetrical T-joints or cross joints
Two-sided connection with different cross-section depth on the right and left
Automatic preliminary design of bolt layout and required stiffening
Optional design mode with possibility to specify all bolt spacing, welds, and sheet thicknesses
Screwability check with adjustable dimensions of used wrenches
Connection classification by stiffness and calculation of the spring stiffness of connections considered in the internal forces determination
Check up to 45 individual designs (components) of the connection
Automatic determination of governing internal forces for each individual design
Controllable connection graphics in rendering mode with specifications of material, sheet thickness, welds, bolt spacing, and all dimensions for construction
Integrated and flexibly extensible settings of National Annexes according to EN 1993-1-8 standard
Automatic conversion of internal forces from structural analysis into respective sections, also for eccentric member connections
Automatic determination of initial stiffness Sj,ini of the connection
Detailed plausibility check of all dimensions, including specifications of input limits (for example, for edge distances and hole spacing)
Optional application of compression forces to a column through contact
Possibility to update the cross-section depth of horizontal beams in case of tapered connections after connection geometry optimization in RF-/FRAME-JOINT Pro
All joint types are considered with the moment release at the column flange, or at the column web in the case of a rotated column. Therefore, the module determines the eccentric moment of a web cleat and fin plate connection, which additionally affects the bolt group at the girder flange.
Further eccentric moments may result from the locations of the angles and sheets. In the case of cleat connection, the forces are transferred separately. Shear forces act on the cleat; tension forces and stabilizing moment are assigned to the bolts. Before the calculation, the connection is checked for geometrical plausibility; for example, the bolt hole spacing and edge distance of the bolts.
There are various options available for beam modeling. A roof type determines the exact purlin location for wind and snow generation.
Two beam types are available: continuous beam and purlin. If you select the continuous beam, it is possible to define several hinge conditions of the beam. If you select the purlin, it is not possible to modify hinge conditions. In this case, the calculation considers a double cross-section in the coupling zone. In addition, several coupling elements are available in the purlin settings:
Nails (prebored/not prebored)
Ring and plate connectors and bolts
Screw connection with fastening system WT from SFS intec
User-defined specification using characteristic strength
The relevant timber grade of the material can be selected from the material library. All material grades for glulam, hardwood and softwood timber specified in EC 5 are available. Furthermore, you have the option to generate a strength class with user-defined material properties and thus extend the library.A comprehensive and extensible material library can also be used for entering permanent loads (for example, roof structure).
Generators integrated in RX-TIMBER Purlin allow for convenient generation of various wind and snow load cases. By clicking the information buttons, the map of wind and snow zones for the relevant country is displayed. The corresponding zone can be selected with a double-click. Load cases can be checked graphically.
However, you can enter load specifications manually as well. According to the generated loads, the program automatically creates combinations for the ultimate and serviceability limit states as well as for fire resistance design in the background.