Non-destructive inspections and the display of inspection results

• US 6,327,921 B1
• Filed: 03/03/2000
• Issued: 12/11/2001
• Est. Priority Date: 03/03/2000
• Status: Expired due to Term

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University
• Inventors: Peters, John J., Hudelson, Nordica A., Hsu, David K., Barnard, Daniel J.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US09/517,957
• Time in Patent Office: 648 Days
• Field of Search: 73/120.1, 73/120.4, 73/120.9, 73/121-- 1, 738/658, 738/665, 735/98, 736/06, 736/07, 736/33, 324/228, 324/237, 324/238, 324/240
• US Class Current: 73/866.5
• CPC Class Codes: G01M 5/0016 of aircraft wings or blades
• CPC Class Codes: G01M 5/005 by means of external apparatus, e.g. test benches or portable test systems
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00
• CPC Class Codes: G01N 2291/2694 Wings or other aircraft parts
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/0645 Display representation or displayed parameters, e.g. A-, B- or C-Scan

Abstract

A non-destructive inspection system makes use of a template that is put on a structure to be inspected to provide an image-based display of inspection results. The template, an example of which is a grid, defines locations on the structure from which inspection data are obtained. A portable display device, an example of which is a laptop computer, with information about the template receives information pertaining to inspection data obtained from locations defined by the template and displays inspection results in an image-based format that corresponds to the template. An example of such a system uses “tap test” non-destructive inspection techniques and provides an image-based display of a plurality of structural stiffness measures, each stiffness measure calculated from a measure of impact duration for a “tap”.

Claims

1. A system for performing a non-destructive inspection of a structure and displaying the results, comprising:

a probe for obtaining non-destructive inspection data at a plurality of locations on the structure, the locations indicated by a template on the structure;

a processor for processing each of the inspection data obtained by the probe to create for each datum an inspection result measure; and

a display device for displaying the plurality of inspection result measures in an image-based format that corresponds to the template.

2. The system of claim 1 wherein the probe is a tap test probe.

3. The system of claim 2 wherein the inspection result measures are measures of impact duration determined from the inspection data.

4. The system of claim 2 wherein the inspection result measures are measures of stiffness calculated using a grounded-spring mechanical model from measures of impact duration determined from the inspection data and the mass of the probe.

5. The system of claim 4 wherein the only feature of a tap test inspection datum that is used in the calculation of a measure of stiffness is a measure of impact duration determined from the inspection data.

6. The system of claim 1 wherein the template is a grid.

7. The system of claim 1 wherein the template is a plurality of lines parallel to one another.

8. A system for performing a tap test inspection of a structure and displaying the results of the structure, comprising:

a tap test probe produces an electrical pulse indicative of the force-time history of impact between the probe and the structure;

a circuit for receiving the electrical pulse from the probe, determining a measure of impact duration, and producing a digital signal indicative of the impact duration measure;

a portable computer for receiving from the circuit a plurality of digital signals indicative of impact duration measures, the plurality of impact duration measure digital signals corresponding to tap test inspection data obtained from the structure at a plurality of locations defined by a template put on the structure, the portable computer including a display for displaying results of the tap test inspection in an image-based format that corresponds to the template.

9. The system of claim 8 wherein the results of the tap test inspection are the plurality of impact duration measures.

10. The system of claim 8 wherein the results of the tap test inspection are a plurality of measures of stiffness calculated by the portable computer from the plurality of impact duration measures.

11. The system of claim 8 wherein the template is a grid defining a plurality of grid squares, and wherein the plurality of grid squares define the locations from which the inspection data are obtained.

12. The system of claim 8 wherein the template is a plurality of parallel lines, and wherein periodic points along the lines comprise the plurality of locations from which the inspection data are obtained.