7. Conclusion

The use of composite enclosures in subsea applications is well established. These materials are already being used in oceanography to protect equipment at great depths, and there is growing interest in them in the offshore field; the exploitation of increasingly deep deposits (> 3,000 m) should accelerate this trend, as the specific properties of composite materials are very attractive in this environment. These applications require in-depth knowledge of the properties of composite materials in biaxial compression, a subject that is difficult to grasp. They also require the development of control methods for thick composites. Last but not least, the critical nature of these structures in oil operations will encourage the development of instrumented composites, to provide information to surface personnel (i.e. on land, on ships or on platforms) on the state of the material at great depths...