NSF Org:	DMS Division Of Mathematical Sciences
Recipient:	UNIVERSITY OF KENTUCKY RESEARCH FOUNDATION, THE
Initial Amendment Date:	August 22, 2001
Latest Amendment Date:	September 13, 2002
Award Number:	0103979
Award Instrument:	Continuing Grant
Program Manager:	Henry Warchall DMS  Division Of Mathematical Sciences MPS  Directorate for Mathematical and Physical Sciences
Start Date:	August 15, 2001
End Date:	December 31, 2004 (Estimated)
Total Intended Award Amount:	$151,177.00
Total Awarded Amount to Date:	$151,177.00
Funds Obligated to Date:	FY 2001 = $56,546.00 FY 2002 = $94,631.00
History of Investigator:	Chi-Sing Man (Principal Investigator) chi-sing.man@uky.edu
Recipient Sponsored Research Office:	University of Kentucky 500 S LIMESTONE LEXINGTON KY  US  40526-0001 (859)257-9420
Sponsor Congressional District:	06
Primary Place of Performance:	University of Kentucky 500 S LIMESTONE LEXINGTON KY  US  40526-0001
Primary Place of Performance Congressional District:	06
Unique Entity Identifier (UEI):	H1HYA8Z1NTM5
Parent UEI:
NSF Program(s):	INFRASTRUCTURE PROGRAM, APPLIED MATHEMATICS
Primary Program Source:	01000102DB NSF RESEARCH & RELATED ACTIVIT app-0102  app-0103
Program Reference Code(s):	0000, 9150, OTHR
Program Element Code(s):	126000, 126600
Award Agency Code:	4900
Fund Agency Code:	4900
Assistance Listing Number(s):	47.049

ABSTRACT

DMS Award Abstract
Award #: 0103979
PI: Man, Chi-Sing
Institution: University of Kentucky
Program: Applied Mathematics
Program Manager: Catherine Mavriplis

Title: Some Studies on Microtexture and Acoustoelasticity in Polycrystalline Media

To the naked eye, the polished surface of a metal sheet appears as a homogeneous continuum. Under the metallographer's microscope the same surface reveals, after etching, an underlying polycrystalline structure. Many materials, including metals, ice and rocks, are aggregates of tiny
crystals or grains, which assume different orientations in space and are separated by interfaces called grain boundaries. Comprehensive mapping of grain boundaries and individual grain orientations in polycrystals has recently become possible with the emergence of orientation imaging microscopy. Details about grain orientations, e.g., the misorientations of neighboring grains, are called microtexture. Microtexture could exert a strong influence on the mechanical behavior of polycrystalline materials (e.g., on the volume of backscattered ultrasonic noise, which
at sufficiently high levels renders ultrasound totally useless for material flaw detection in aircraft engines; an undetected metallurgical defect in the No. 2 engine was the culprit for the crash of a United Airlines DC-10 in 1989).

The main objectives of the present project are as follows: (i) to reexamine the mathematical foundations and properties of several theoretical constructs which have been proposed by material scientists for describing microtexture in various degrees of detail and sophistication; (ii) to delineate the effects of microtexture on the mechanical anisotropy of sheet metals in forming operations; (iii) to study the effects of microtexture on the acoustoelastic behavior of stressed polycrystals; (iv) to develop further an earlier study that concerns using the dispersion of Rayleigh waves for the nondestructive inspection of surface layer of residual stress, which is imparted on critical components of aircraft engines to enhance their high-cycle fatigue performance.


Date: May 18, 2001

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