Design guidelines for beam joints

According to VDI 2230 guidelines.
Beam joints
Item Guidelines for design Disadvantages Advantages
1 Preloads: Preloads as high as possible *higher strength grade *exact tightening method *low coefficients of friction Low preloads High preloads (choose tightening method with small tightening factor)
Width of beam: Utilise the recommended beam width b=dw =h if possible 
Very narrow joints
Beam Joint Diagram 1
Width of b=dw =h min beam
Beam Joint Diagram 2
Height of the beam: Greater beam heights result in lower additional bolt forces 
Small height of beams
Beam Joint Diagram 3
Large height of beams
Beam Joint Diagram 4
Overhang: If possible, design an overhang so that the supporting effect can completely develop. Point U (limit of the bearing surface) is defined by a step. 
Minimal overhang
Beam Joint Diagram 5
Overhang ü =h
Beam Joint Diagram 6
Connecting parts: The additional bolt force (difference force) decreases when when the connecting parts force a parallel movement on the beam 
Loose coupling
Beam Joint Diagram 7
Tight coupling
Beam Joint Diagram 8