on the Basics of Bolted Joints
The Effect of Joint Deformation loss
due to Embedding
A joint diagram showing the effect of embedding is presented below.
When a bolt is tightened, very high local pressures can exist in the contact areas
on the threads and under the nut/bolt. Local plastic deformation
can occur at these interfaces by flattening of surface roughness.
This plastic deformation has the effect of reducing a bolt's
preload. Research has been completed to establish guide values
for the amount of embedding that typically occurs within joints.
The amount of embedding determined is a loss of joint deformation.
This can be converted into force by calculation or by the
aid of a joint diagram.
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