Bonded-bolted joints load distribution

Bonded-bolted joints have good load distribution and are generally designed so that the bolts take all the load. Then, the bolts would take all the load after the bond breaks (because the bolts do not receive load until the bond slips). The bond provides a change in failure mode and a sizable margin against fatigue failure. 

Figure 5.44 Load distribution in a bonded-bolted joint with a joint end debond.

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. 

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