Stresses Within Compound Tubes Comprising a Steel Liner and an External Carbon-Fiber Wrapped Laminate

There is increasing interest in techniques that permit weight reduction of thick cylinders, particularly gun barrels. The method examined within this paper involves the external wrapping of a carbon fiber-based laminate jacket around a steel liner. Various design options are examined, e.g., prior autofrettage of a steel liner followed by external tension wrapping and benign wrapping of a stress-free steel liner followed by autofrettage of the assembly. Outcomes include optimum overstrain and machining of the steel liner, identification of a potential “crushing” failure mode due to radial compressive stresses and techniques for application of tension wrapping which optimize hoop stress within the composite jacket. Finally, possible combinations of fiber orientations are discussed.