Bolted Connections in Solar Installations: Relaxation

When considering bolted joints in solar installations, there are a few factors that may influence the connection’s integrity, one of which is relaxation.

All joints experience some relaxation after assembly with an accompanying loss of preload. Additional relaxation may occur during the service life of the joint depending on time, loading type and level, and environment. If a joint relaxes too much, loss of preload may result in joint separation and failure.

In order to combat relaxation of a bolted assembly in a solar installation, take the following precautions:

• Limit joint interfaces.

• Ensure smooth surfaces.

• Control parallelism of joint surfaces.

• Use flange head bolts and flange nuts to reduce bearing stresses against joint material.

• Use hardened washers under bolt head and nut to distribute bearing stresses.

• Use smaller diameter higher strength bolt to increase elasticity.

If you have questions about how to minimize the threat of relaxation in bolted joints, please contact us.