• Present invention describes a mechanical metamaterial (MM) add-on filter for the transducer for the enhancement of linear & non-linear ultrasonic damage detection on cylindrical rod structures.
• Said mechanical metamaterial add-on filter placed along the cylindrical rod with an array of axisymmetric metamaterial baffles arranged periodically on the surface of the rod for harmonic filtering of signals,
• The axisymmetric metamaterial baffles are either constant axisymmetric baffles or tapered axisymmetric baffles enclosed in a shell. (Refer Figs. 1a, 1b, 1c)
• Further claimed a system for generating & directing ultrasonic waves for inspections of specimens using the add-on filter, said system comprises:

1. a custom-made holder setup to attach transducer & add-on assembly to the workpiece for proper ultrasonic wave propagation;
2. a device to generate the electric pulses for the transducer;
3. an ultrasound pulser receiver device used for receiving the ultrasonic waves;
4. an oscilloscope used to display the signals, &
5. a computer to process the signal.

(Refer Fig 4: Prototype of the claim system)

• Facilitates a technique that aims to isolate certain guided wave modes in cylindrical waveguides that play a key role in the fluid flow & temperature measurement process.
• The waveguide metamaterial suppresses all the unwanted nonlinearity by creating an ultrasonic bandgap near the fundamental frequency range.
• Facilitates a long-range inspection as well as inspect micro & fatigue cracks.