Full Strength Bolted End Plate Connections
It consists of 3 different types.
The factors determining the behavior of the combination; beam cross-section reaching to yield under bending effect, end plate reaching to yield under bending effect, yielding of column panel area, rupture of bolts under tensile effect, rupture bolts under shear effect.
The controls listed above are applied automatically and detailed explanations and references and parameters used in the account are given in the report.
There are conditions that must be met in order to be used in 3 types of frames with special moment frames or intermediate moment frames. These conditions are given in AISC 358-16 6.3. ideCAD Static automatically checks and reports these conditions.
Plastic hinges cause inelastic bending deformations in the joining beam and column panel area in the joints with end plate. Therefore, strong column, strong joint and weak beam design are considered as philosophy. For this reason, the length of the plastic hinge and its distance from the column face are especially checked in the table below.
Also, ıt should be checked that:
The clear span-to-depth ratio of the beam shall be limited as follows:
(a) For SMF systems, 7 or greater.
(b) For IMF systems, 5 or greater.The protected zone is determined:
(a) For unstiffened extended end-plate connections: the portion of beam between the face of the column and a distance equal to the depth of the beam or three times the width of the beam flange from the face of the column, whichever is less.
(b) For stiffened extended end-plate connections: the portion of beam between the face of the column and a distance equal to the location of the end of the stiffener plus one-half the depth of the beam or three times the width of the beam flange, whichever is less.The end-plate should be connected to the flange of the column.
Rolled shape column depth is limited to W36 (W920) maximum. The depth of built-up wide-flange columns is not exceed that for rolled shapes.
End Plate Connections Design Steps
The strength of end plate connection is determined by the assumption that tensile force of the bolts in one flange is controlled by rupture limit state under compressive force in the other.
If there is no axial load on the joint, the total tensile and compressive forces are equal and opposite in both flanges, so that the total force creates a force pair.
The row of bolts farthest from compression flange is considered as the region subject to the greatest tensile force, and while the inverse triangular force distribution is considered for ease of calculation, and a ductile joint is calculated on a parabolic distribution according to the plastic force distribution assumption.
Flexural strength of end plate and column flange is determined by yield line analysis. The yield line method can be calculated by the energy or virtual work method.
Strong column, strong joint and weak beam are used to calculate the forces on the bolt and to find the required bolt strength. According to this assumption, while the column, panel region and beam inelastic behavior, the joint and column show elastic behavior. For this reason, it is necessary to design suitable for the thick plate for end plate. In thick plate behavior, the force in the bolts is the static moment at the center of comprensive flange.
The equations used are as follows:
Boundary Situations to Check
Effective Force | Connection Element | Reference |
---|---|---|
Tension | Bolt (Tension) | a |
Tension | Plate (Flexural) | b |
Tension | Column flange (Flexural) | c |
Tension | Beam web (Tensile) | d |
Tension | Column web (Tensile) | is |
Tension | Flange - Plate welding | f |
Tension | Web-Plate welding | g |
Horizontal Shear | Column web (Shear) | h |
Compression | Beam flange (Compression) | j |
Compression | Beam flange welding | to |
Compression | Column web | l |
Vertical Shear | Web - Plate welding | m |
Vertical Shear | Bolt (Shear) | n |
Vertical Shear | Bolt (Bearing) | p |