Composite overwrap repairs materials

In 2006, the first revision of two international codes, one by the International Organization for Standardization (ISO), ISO/TS-24817 (ISO, 2006) and the other the ASME PCC-2 (ASME, 2006), were published to assist engineers in designing a reliable composite overwrap repair. The former is recognised as a general code that covers pipes with different materials from steel to FRP while the latter is specifically focused on steel pipes. 

The behaviour of pipes repaired with composite overwraps has been studied by many researchers in order to understand the effects of different parameters such as material properties and loading conditions. 

Unlike the case of a composite clamp which is manufactured under shop-floor conditions that allow close control of the curing process, overwrap repairs are applied and cured in the field. Hence, it is not always practical to replicate laboratory cure conditions and the surface preparation of the substrate that have been used to determine the properties and performance of the overwrap repair system. To this end, a good understanding of the cure behaviour of the overwrap composite material and the composite—substrate interface properties is essential to ensure that repairs are properly applied and the acceptable performance is achieved in the field. 

Leong, A.Yi., Leong, K.H., Tan, Y.C., Liew, P.F.M., Wood, C.D., Tian, W., Kozielski, K.A., 2011. Overwrap composite repairs for offshore risers at topside and splash zone. In 18th International Conference on Composite Materials, Korea. 

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