Bolted connections, shear loads

Procedure 6-3 Design of Square and Rectangular Platforms, 304 Procedure 6-4 Design of Pipe Supports, 309 Procedure 6-5 Shear Loads in Bolted Connections, 317 Procedure 6-6 Design of Bins and Elevated Tanks, 318 Procedure 6-7 Agitators/Mixers for Vessels and Tanks, 328 Procedure 6-8 Design of Pipe Coils for Heat Transfer, 335 Procedure 6-9 Field-Fabricated Spheres, 355 References, 364... 

The tensile-shear loading was realised in a set-up involving the three specimens of the same batch as follows. The bottom leg of the top specimen was connected to the top leg of the middle specimen with a bolt with a washer of the same thickness as that of the given adhesive layer in order to assure symmetrical loading. The middle specimen was connected in a similar way to the lowest specimen (Fig. 25). 

A typical shear stress or strain distribution in an adhesively bonded lap joint is shown in Figure 5.38. If fasteners are placed in conventional positions (i.e. metal bolted connections), they are located in the area of minor shear stresses. Therefore, when the joint is undamaged the fasteners will be only moderately loaded. 

Shear loads in bolted connections are classified as either Friction Type or Bearing Type . A brief definition is as follows ... 

A failure of the bolted joints will most likely occur because of excessive loads under the bolt and washer. The high loads on the cover will eventually cause the molded Minion to creep under the bolt and make it lose its initial bolt preload. At this point vibration and external loading will cause further loosening of the bolt and a loss of compression between parts. The proper preload on the fastener is required to prevent loosening of the bolt, provide a frictional force between parts to resist bolt shear, and improve the fatigue resistance of the bolt connection. 

This type of construction uses precast concrete walls with steel or concrete frames (Figure 4.2). The frame resists all vertical loads and precast shear walls resist lateral loads. Ductile connections for precast panels are an important consideration. Precast panels are made with embedded steel connection devices attached to the building frame by bolting or welding. The roof is usually a concrete slab on metal deck. The metal deck is attached to steel framing by studs or puddle welds. Tins type of construction can be economically designed to withstand blast loading on the order of 7 to 10 psi (48 to 69 kPa) side-on overpressure. 

A typical shear connection for a wall girt might consist of a relatively thin two bolt shear tab. As a blast load is applied to the girt, tearout of the tab may occur due to an inadequate number of bolts or insufficient weld capacity. This will prevent development of plastic moment capacity of the member and thus reduce its blast resistance. A typical upgrade for this type of connection is addition of a new shear tab wetded or bolted to the existing column and girt. 

P(5) Holes for structural connections using bolts loaded in shear shall be formed so that each bolt is a close fit in the mating holes of the parts to be joined and so that no loads due to misaligned holes are imparted to either of the FRP laminates being joined. 

Column and beam end rotations were measured by LVDTs installed at the member ends of the first and second stories. Load cells were located between actuators and test frame to measure story forces. Shear deformation of infill walls were monitored by diagonally positioned LVDTs on infill walls of the first and second stories. Reactions (bending moment, axial force and shear force) at the base of external columns were measured using two special force transducers (Canbay et al. 2004). These transducers were manufactured, calibrated, and placed between the base of external columns and the foundation. Longitudinal reinforcements of external columns were welded to base plates that were connected to transducers. Transducers were fixed to the fomidation block by using bolts. 

The most critical area of the tower design is the tower-to-foundation connection. Both shear forces and moments are at a maximum at this point. Anchor bolts are generally used at the base of steel towers. Such bolts must be proportioned to transfer overturning loads from the tower to the bolts. The bolts must be deeply embedded in the concrete footing block in order to transfer their loads to the footing reinforcement. 

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