Method and apparatus for visualization of internal stresses in solid non-transparent materials by elastoacoustic technique
AssigneeThe United States of America as represented by the Secretary of Commerce
InventorEwa Drescher-Krasicka
Life of this patent
Estimating the term…
Abstract
A process and apparatus for visualization of internal stresses in solid materials by an acoustic microscope (10) connected to an acoustic lens (5) having a circular or spherical transmitting and receiving surface (8) for transmitting ultrasonic waves to and receiving reflected waves from a sample (3) to be examined in a body of liquid (2), such as water, a motor drive unit (7) having a movable arm thereon (6) connected to the acoustic lens (5) for supporting and moving the lens for scanning the sample, the motor drive (7) being connected to the acoustic microscope (10) for being operated thereby to perform the scanning, a computer (16) having a visual display unit (18), and an oscilloscope (20) for indicating the reflected waves.
Claims20
A process for visualization of internal stress in solid materials by acoustic microscope imaging comprising:
- providing an coustic microscope having an acoustic lens comprising an ultrasonic transmitter and an ultrasonic receiver;
- supporting a sample comprising a body of solid material to be examined;
- supporting said acoustic lens in spaced relationship to said sample;
- defocusing said lens by adjusting the focal point of said lens beneath the surface of said sample;
- exciting said ultrasonic transmitter to produce transmitted ultrasonic waves;
- directing said transmitted waves toward said body;
- positioning said acoustic lens relatively to said sample for receiving acoustic waves reflected from said sample and produced by said transmitted waves;
- and
- measuring the amplitude of said received waves to analyze distribution of internal stress in said sample.
An apparatus for visualization of internal stresses in solid materials by acoustic microscope imaging comprising:
- means for supporting a sample to be examined;
- ultrasonic transmitter means supported in spaced relationship to said sample support means for transmitting ultrasonic waves toward the sample;
- ultrasonic receiver means f or receiving ultrasonic waves reflected from said sample;
- motor drive means operatively connected to said transmitter and receiver means for moving said transmitter and receiver means with respect to said sample for scanning said sample;
- acoustic microscope means operatively connected to said ultrasonic transmitter means, ultrasonic receiver means and motor drive means for operating said motor drive means, exciting said ultrasonic transmitter means to produce said ultrasonic transmitted waves, and for receiving signals from said ultrasonic receiver means produced by said reflected waves so that said acoustic microscope detects differences in intensity of said reflected waves as an indication of internal stress in said sample;
- and
- computer means operatively connected to said acoustic microscope for controlling said acoustic microscope and receiving signals therefrom indicating said differences in intensity of said signals transmitted by said ultrasonic receiver and for visually displaying said signals from said acoustic microscope to show said differences in intensity.
Dependencies are inferred from the claim text.