SYNTHETIC PULSE METHODS FOR ULTRASONIC NONDESTRUCTIVE EVALUATION (NDE)

Award Information
Agency:
Department of Energy
Branch
n/a
Amount:
$379,000.00
Award Year:
1986
Program:
SBIR
Phase:
Phase II
Contract:
n/a
Agency Tracking Number:
2560
Solicitation Year:
n/a
Solicitation Topic Code:
n/a
Solicitation Number:
n/a
Small Business Information
Sigma Research Inc.
8411 154th Ave Ne, Redmond, WA, 98052
Hubzone Owned:
N
Socially and Economically Disadvantaged:
N
Woman Owned:
N
Duns:
n/a
Principal Investigator:
Mr. T.j. Davis
Principal Investigator
(206) 881-1807
Business Contact:
() -
Research Institution:
n/a
Abstract
LARGE-GRAIN MATERIALS ARE DIFFICULT TO INSPECT WITH CONVENTIONAL ULTRASONIC NONDESTRUCTIVE EVALUATION (NDE) METHODS. THIS IS PARTICULARLY TRUE OF THE CEN- TRIFUGALLY CAST STAINLESS STEEL USED FOR COOLANT PIPING IN PRESSURIZED WATER REACTORS (PWR). REDUCED TEST FREQUENCIES MUST BE USED TO PENETRATE THE MATERIAL. HOWEVER, A CORRESPONDING DECREASE IN NEAR-SURFACE RESOLUTION IS INCURRED RESULTING IN A MARGINAL TEST FOR WELD FLAWS. THE PLANNED WORK WILL EVALUATE A POTENTIAL TECHNIQUE FOR COMBINING DEEP PENETRATION WITH EXCELLENT NEAR-SURFACE RESOLUTION. THIS TECHNI- QUE SYNTHESIZES A BROADBAND IMPULSE BY TESTING THE PART WITH A SERIES OF DISCRETE TEST FREQUENCIES. THE FOURIER COEFFICIENTS OF EACH FREQUENCY ARE STACKED TOGETHER TO BUILD A CONTROLLED SPECTRUM. TAKING THE INVERSE FOURIER TRANSFORM RECONSTRUCTS A BROADBAND PULSE THAT SHOULD CONTAIN THE DESIRED FLAW INFORMA- TION. AN OUTSTANDING ADVANTAGE OF THE TECHNIQUE IS THAT THE INDIVIDUAL SPECTRAL COMPONENTS MAY BE AD- JUSTED TO OPTIMIZE THE OUTPUT PULSE.

* information listed above is at the time of submission.

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