Title :
Effect of stress on energy flux deviation of ultrasonic waves in GR/EP composites
Author :
Prosser, William H. ; Kriz, R.D. ; Fitting, Dale W.
Author_Institution :
NASA Langley Res. Center, Hampton, VA, USA
Abstract :
Ultrasonic waves suffer energy flux deviation in graphite/epoxy because of the large anisotropy. The angle of deviation is a function of the elastic coefficients. For nonlinear solids, these coefficients and thus the angle of deviation is a function of stress. Acoustoelastic theory was used to model the effect of stress on flux deviation for unidirectional T300/5208 using previously measured elastic coefficients. Computations were made for uniaxial stress along the χ3 axis (fiber axis) and the χ1 axis for waves propagating in the χ1χ3 plane. These results predict a shift as large as three degrees for the quasi-transverse wave. It is noted that the shift in energy flux offers a new nondestructive technique for evaluating stress in composites
Keywords :
carbon fibre reinforced plastics; stress measurement; ultrasonic materials testing; C; acoustoelastic theory; angle of deviation; elastic coefficients; energy flux deviation; fiber axis; graphite fiber reinforced epoxy resin composites; nondestructive technique; nonlinear solids; quasi-transverse wave; ultrasonic waves; uniaxial stress; Anisotropic magnetoresistance; Elasticity; Laminates; NASA; NIST; Optical fiber theory; Stacking; Tensile stress; Ultrasonic variables measurement; Vectors;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171505
