Non Destructive Evaluation International (NDEI) was contacted by Composite Resources, an Engineering and Manufacturing facility located in Rock Hill, SC to analyze and proof their design concepts for a specialty, high pressure composite vessel. NDEI developed a custom-tailored inspection procedure for the testing of the Ultra-lite pressure vessels using state of the art Acoustic Emission Testing. The testing procedure begins by setting up the individual vessel to be tested on a hydrolic press, this helps to simulate the actual in-service application of the vessel. Next, four (4) Piezoelectric transducers are then mounted to the outside of the composite shell; these sensors convert the mechanical stress waves of an active defect into an electrical impulse that is then transmitted to the AE instrumentation. The vessel is then filled with water and purged of all air prior to the pressurization process. The AE test begins with the vessel at atmospheric pressure (referred to as background) , then the vessel is pressurized using the following step-up/step-down procedure: 50 psi; 100 psi; 50 psi; 150 psi; 100 psi; 200 psi; 150 psi; 200 psi.
Each pressure level is held for 1 minute (referred to as a static hold), so that the presence of any transient elastic stress waves can be recorded. NDEI and Composite Resources continued collaboration has produced a synergy that not only aides in improving quality manufacturing techniques, but allows for a defect-free product to be shipped to the customer.

NDEI uses acoustic emission testing to analyze and proof

Design concepts at composite resources.

January 2006

Company UPDATE:

NDEI Teams up with Composite Resources