There is a composite sleeve on the market that is being considered for not only repair of defective pipelines but also reinforcement of pipelines in selected areas. In this particular case, two 180 deg sleeves surround the pipe and are attached with a specific epoxy bonding material along the entire inside surface of the sleeves. For example, if there is a 12" diameter API 5L pipe, .375" wall, two half sleeves of 12.75 ID x .375" wall, 3' long would be bonded to the carrier pipe. The sleeve is also API 5L.

Tests have been performed to show that the bonded section is stronger than the base pipe for hoop stress, longitudinal pressure and bending. We have a shear stress allowable for the bonding agent.

This type of approach has been used for many years for temporary repair of damaged pipelines, to avoid shutdown and emptying costs without welding to the pipe. Clock Spring repairs may be a term you are familiar with.

In this case we are trying to analyze the stresses in the pipe at a reinforcement area for "permanent installation", perhaps at creek banks where the soil may erode. Since there is a "continuous bond" between the carrier pipe and sleeve it is unclear how to model this reinforced area. It is slightly analagous to a welded on saddle at a TEE, but saddles are really not analyzed except to include a SIF. This is not plastic pipe, so bonding is not the same.

Does anyone have any suggestions on how to analyze reinforcement sleeves of steel half sleeves bonded to steel pipe?