Development of a Membrane Coupled Conformable Phased Array

The non-destructive inspection of components with irregular surface geometry can be very challenging. The performance of inspections using conventional rigid wedge ultrasonic transducers is limited because of inconsistent coupling and beam distortion. A novel approach using a membrane coupled conformable phased array device is under development to reduce these problems. This lowcost, robust device uses a standard phased array coupled to the component surface via a fluid-filled, low-loss polyurethane membrane. The performance of the membrane-coupled device has been improved to reduce the required coupling force, increase inspection speed and reduce probe noise. The evolution of the membrane-coupled device is presented and the performance improvements over previous designs are discussed. A comparison between the membrane coupled conformable phased array and conventional rigid wedge technology is then completed. This comparison demonstrates that the membrane device can theoretically be used to reduce inspection time by approximately a factor of three when compared to the single crystal approach. This significant time reduction is achieved whilst improving inspection coverage, flexibility and performance, as well as reducing the amount of user intervention.