Method and system of non-destructive testing for composites

Patent metadata

Field	Value
Publication number	US-10697941-B2
Application number	US-201314386449-A
Country	US
Kind code	B2
Filing date	Mar 20, 2013
Priority date	Mar 20, 2012
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Method and system are disclosed for characterizing and quantifying composite laminate structures. The method and system take a composite laminate of unknown ply stack composition and sequence and determine various information about the individual plies, such as ply stack, orientation, microstructure, and type. The method and system can distinguish between weave types that may exhibit similar planar stiffness behaviors, but would produce different failure mechanisms. Individual ply information may then be used to derive the laminate bulk properties from externally provided constitutive properties of the fiber and matrix, including extensional stiffness, bending-extension coupling stiffness, bending stiffness, and the like. The laminate bulk properties may then be used to generate a probabilistic failure envelope for the composite laminate. This provides the ability to perform non-destructive QA to ensure that individual lamina layup was accomplished according to specifications, and results may be used to identify a numerous laminate properties beyond purely structural.

First claim

What is claimed is:

1. A computer-aided non-destructive method of quantifying individual laminas in a composite laminate, the method comprising:
controlling a z-start time and a z-gate time of at least one pulse-wave detector to generate ultrasonic composite scan data:
processing the ultrasonic composite scan data using a processor to generate an array of data for a plurality of spatial locations across a surface of the composite laminate, the array including signal intensity data and signal time-of-flight data for a signal reflected off material transitions within the composite laminate as a function of the z-start time and the z-gate time;
calculating lamina properties by the processor based on the processed composite scan data, the lamina properties including ply type, including unidirectional or weave, weave type and at least one or more other lamina properties including number of individual laminas, and thickness of each individual lamina;
determining fiber and matrix moduli and failure parameters and in response calculating a failure load for the individual laminas by the processor based on the one or more lamina properties; and
generating a probabilistic failure envelope by statistically determining the probabilistic failure envelope for the composite laminate by the processor using one or more of the lamina failure parameters.

2. The method according to claim 1 , wherein the fiber orientation of each individual lamina is determined by numerically integrating the array in an X direction and a Y direction for a plurality of layers for each individual lamina to identify a primary fiber orientation and at least a secondary fiber orientation indicative of a weave for at least one layer of each individual lamina.

3. The method according to claim 2 , wherein the mathematical transform comprises performing one of the following for the at least one layer of each individual lamina: a Radon transform, a Hough transform, an Eigensystem analysis, and a Fast Fourier transform.

4. The method according to claim 2 , further comprising numerically determining by the processor using the array of processed composite scan data whether the at least one layer of each individual lamina is unidirectional or weave based on the primary fiber orientation and secondary fiber orientation of the at least one layer of each individual lamina.

5. The method according to claim 1 , wherein the array of composite scan data is ultrasonic C-scan data.

6. The method according torr 1 , wherein the array of composite scan data is one of the following: data simulated by a simulated ultrasonic C-scan, and data acquired by a real ultrasonic detector.

7. The method according to claim 1 , wherein determining one or more lamina properties by the processor comprises processing the composite scan data using filters, thresholding, and morphological features.

8. A computer system for non-destructive quantifying of individual laminas in a composite laminate, the computer system comprising:
a processor;
a storage device connected to the processor, the storage device storing an application thereon for causing the processor to:
process ultrasonic composite scan data received into the computer system from an ultrasonic scanner, the processed ultrasonic composite scan data representative of a composite scan of the composite laminate, the ultrasonic composite scan data indicating, for each one of an array of spatial locations across a surface of the composite laminate, signal intensity and signal time-of-flight for a signal reflected off material transitions within the composite laminate;
calculate lamina properties based on the composite scan data, the lamina properties including ply type, including unidirectional or weave, weave type and at least one or more other lamina properties including number of individual laminas, and thickness of each individual lamina;
determine a fiber and matrix moduli and failure parameters and in response calculate a failure load for the individual laminas based on the one or more lamina properties; and
generate a probabilistic failure envelope by statistically determining the probabilistic failure envelope for the composite laminate using one or more of the lamina properties and the failure load for the individual laminas;
wherein the processor determines ply type by determining whether each individual lamina is unidirectional or weave based on fiber orientation of each individual lamina by processing the array of signal intensity data and signal time-of-flight data at a given depth within the laminate.

9. The computer system according to claim 8 , wherein the fiber orientation of each individual lamina is determined by the processor using a mathematical transform to identify a primary fiber orientation and a secondary fiber orientation indicative of a weave for each individual lamina, and the processor controls a z-start time and a z-gate time of a plurality of pulse-wave detectors to generate ultrasonic composite scan data for a plurality of layers for each individual lamina.

10. The computer system according to claim 9 , wherein the mathematical transform may be one of the following: a Radon transform, a Hough transform, an Eigensystem analysis, and a Fast Fourier transform, and is performed one or more layers of a plurality of layers for each individual lamina.

11. The computer system according to claim 9 , the processor determines whether each individual lamina is unidirectional or weave based on the primary fiber orientation and secondary fiber orientation of at least one layer of a plurality of layers for each individual lamina and the array is generated using sub-microsecond z-gating times and ultrasonic frequencies equal or greater than about 10 MHz.

12. The computer system according to claim 8 , wherein the composite scan data is ultrasonic C-scan data that is obtained for a plurality of layers of each of one or more lamina.

13. The computer system according to claim 8 , wherein the composite scan data is one of the following: data simulated by a simulated ultrasonic C-scan, and data acquired by a real ultrasonic detector for a plurality of layers of each of one or more lamina.

14. The computer system according to claim 8 , wherein the processor determines the one or more lamina properties by processing the composite scan data using filters, thresholding, and morphological features.

15. A non-transitory computer-readable medium containing computer-readable instructions for instructing a computer to perform non-destructive quantifying of individual laminas in a composite laminate, the computer-readable instructions comprising instructions for causing the computer to:
process ultrasonic composite scan data from an ultrasonic scanner, the ultrasonic composite scan data representative of a composite scan of the composite laminate, the ultrasonic composite scan data indicating, for each one of an array of spatial locations across a surface of the composite laminate, signal intensity and signal time-of-flight for a signal reflected and refracted off material transitions within the composite laminate;
calculate lamina properties based on the processed composite scan data, the lamina properties including ply type, including unidirectional or weave, weave type and at least one or more other lamina properties including number of individual laminas, and thickness of each individual lamina;
determine fiber and matrix moduli and failure parameters and in response calculate a failure load for the individual laminas based on the one or more lamina properties; and
generate a probabilistic failure envelope by statistically determining the p

Assignees

• Univ Baylor

Inventors

• Jack David A
• Fitch John E
• Vo Theresa

Classifications

• G06F2113/26

  Composites · CPC title

• G06F2111/08

  Probabilistic or stochastic CAD · CPC title

• G06F30/20 Primary

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G01N29/06

  Visualisation of the interior, e.g. acoustic microscopy {(medical or veterinary diagnosis using sonic waves A61B8/00; representation of acoustic wave distribution G01H3/125, G01H9/002; short-range imaging systems using reflection of acoustic waves G01S15/8906)} · CPC title

• G01N29/449 Primary

  Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation · CPC title