NDE performance in predicting failure strength of spherical composite specimens with implanted flaws
The results of a program to evaluate nondestructive inspection techniques on spherical composite specimens are presented. Seventy Kevlar-epoxy filament wound specimens were made such that ten of the specimens contained one of seven defect conditions which simulated manufacturing or handling defects. These defect conditions were a standard no-defect condition, Teflon-shim simulated delamination, ceramic bead simulated voids, 10% low-fiber alternate winding pattern, low-modulus alternate fiber type, variable tension, and dry (low-matrix) fiber. Some specimens were impact damaged by dropping them from various heights to a hard surface. Each specimen was inspected using a variety of nondestructive techniques to determine which methods were useful for detecting the defect conditions in the specimens. These techniques included combinations of A, B, and C-scan ultrasonics, acousto-ultrasonics, x-ray CAT scans, radiography, thermography, optical stress coating, and acoustic emission. The specimens were subsequently pressurized to failure to determine any detrimental effect the implanted flaw types might have on enclosed geometry structures. One important finding in the study was that nominal defects introduced during the manufacturing or handling process do not significantly reduce the ultimate burst strength of the composite material in this geometry when creep and fatigue mechanisms are insignificant. 11 refs., 12 figs.
- Research Organization:
- Oak Ridge Y-12 Plant, TN (USA); Virginia Polytechnic Inst. and State Univ., Blacksburg (USA); Delaware Univ., Newark (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5022236
- Report Number(s):
- Y/DW-741; CONF-880487-1; ON: DE88008223
- Resource Relation:
- Conference: American Society of Nondestructive Testing (ASNT) spring conference, Orlando, FL, USA, 11 Apr 1988
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DEFECTS
NONDESTRUCTIVE TESTING
COMPARATIVE EVALUATIONS
ACOUSTIC EMISSION TESTING
CAT SCANNING
FAILURES
PERFORMANCE
SIMULATION
THERMOGRAPHY
VOIDS
X-RAY RADIOGRAPHY
ACOUSTIC TESTING
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
INDUSTRIAL RADIOGRAPHY
MATERIALS TESTING
MEASURING METHODS
TESTING
TOMOGRAPHY
420500* - Engineering- Materials Testing