Acoustic emission and failure prediction for pressurisation experiments on helicopter air bottles.

Two spherical high pressure bottles of high-tensile steel were pressurised to destruction to evaluate acoustic emission monitoring as a non-destructive test on similar bottles. One bottle was tested with an artificially introduced defect of sufficient size to reduce the failure pressure to the proof-test pressure; the other contained no flaws. In neither bottle was sufficient acoustic emission detected to enable monitoring to be of value for non-destructive testing