For the European code EC 3, the following types of connections with the front plate are available: beam-beam and column-beam. These connections can be designed as welded or bolted. When bolted, the connections can use both ordinary and prestressing bolts.
The software verifies the strength of all components of a connection [6.2], evaluates its stiffness [6.3], and checks conditions of the connection's ability of rotation (which guarantee that a plastic hinge will be created [6.4]).
In general, the following connection components are verified:
Forces in individual bolt rows and connection resistances for bending are calculated according to the algorithm given in point 6.2.7.2.
For tensile forces exceeding 5 percent of the beam tensile strength, the software calculates forces in successive rows of bolts, applying the same algorithm as for bending, and excluding the components subjected to compression. Tensile resistance of a connection is a sum of forces in individual bolt rows.
Stiffness of a connection is calculated as a resultant of stiffnesses of all components of the connection. The computational algorithm for calculation of stiffness is provided in point 6.3 of the code.
A connection may be classified due to stiffness, according to point 5.2.2 of the code, or due to resistance, according to point 5.2.3. The evaluated stiffness of a connection can be ascribed to a structure by defining additional elastic releases in the analyzed connection. Recalculation of the structure enables more accurate estimation of loads acting on a connection.
Stiffness of a connection will not be calculated if either of the following occurs:
Using options on the Bolts tab, you can define a diameter and class of bolts used in a connection and arrange bolts with precision in relation to the front plate edge. A number of rows and columns should be defined in the Rows and Columns fields (NOTE: in the current version, it is possible to define only 2 bolt columns).
Use Distance h1, Vertical spacing, and Horizontal spacing to determine the location of rows and columns with respect to one another, and the location of the top row with respect to the upper edge of the front plate. If you select Equal spacing, then the same values will be chosen for all elements from the list (the first element from the list is always assumed as the basis of a sequence).
The Friction coefficient {mi} and the Conditional coefficient {ks} are active for B and C class connections. They are used to calculate the resistance for slipping of a contact area of a prestressed connection according to point [3.9] of the code.
Using options on the Bolts tab, you can define a diameter and class of bolts used in a connection and arrange bolts with precision in relation to the front plate edge. A number of rows and columns should be defined in the Rows and Columns fields (NOTE: in the current version, it is possible to define only 2 bolt columns).
Point 3.4 of the EN 1993-1-8 code defines 5 basic connection categories. Due to shear, a connection can be ascribed to 1 of 3 categories: A, B, or C. Considering tension, a connection can be classified as a D or E category connection. Thus, if a complete set of internal forces is acting on a connection, the connection with the front plate may be classified according to 2 different categories.
In accordance with Table 3.2, connections in category A should be checked for bolt rupture in the ultimate limit state (ULS). Connections in category B should be verified against bolt rupture in the ULS and against slipping of a contact area in the serviceability limit state (SLS). Connections in category C should be checked in the ULS, both for bolt rupture and loss of a contact area.
In the case of tension, verification of connections in categories D and E proceeds analogously. Therefore, it is not required to determine a connection category for tension.
The following loads are considered when performing calculations of connections in the ULS:
The following loads are considered when performing calculations of connections in the SLS:
Depending on a connection category defined on the Code parameters tab, the software automatically recognizes load cases defined in the Connection Calculations dialog and performs appropriate calculations. A connection check can be carried out simultaneously due to all types of load cases; if both ULS and SLS cases are defined for a B category connection, then the software automatically considers all ULS cases to check the connection for bolt rupture. To check the connection for slipping of a contact area, it will adopt all SLS cases.
To increase the column stiffness, you can define horizontal stiffeners of the column web, diagonal stiffeners, and an additional plate to stiffen the web. If a connection includes a diagonal stiffener, it is possible to define an additional stiffener of the beam web in the place where the beam touches the stiffener flange.
Define code parameters:
It is possible to select a frame type. The beam length assumed in calculations is equal, by default, to the real beam length.