#### Location

Snowmass Village, CO

#### Start Date

1-1-1995 12:00 AM

#### Description

Assessment of structural safety requires knowledge of the shape of any defect and the stresses acting on it. Ultrasonics can be used to measure applied stress since there is a (small) change in velocity with stress. However the problem becomes more difficult when measuring residual stress. Here the influence of other factors such as variation in microstructure must be accounted for. For example, one method is to measure the percent difference in velocity of orthogonally polarized shear waves (the acoustic birefringence B). When the material symmetry and stress axes coincide [1], B=Bo+CaD where Be is the birefringence in the unstressed state, Ca is the acoustoelastic constant and D is the difference of principal stresses. The usual procedure is to measure B at a “reference” location where stresses are known, and assume homogeneity of microstructure.

#### Volume

14B

#### Chapter

Chapter 6: Material Properties

#### Section

Stress and Texture

#### Pages

1877-1882

#### DOI

10.1007/978-1-4615-1987-4_240

#### Copyright Owner

Springer-Verlag US

#### Copyright Date

January 1995

#### Language

en

#### File Format

application/pdf

Measurement of Plane Stress States using Electromagnetic-Acoustic Transducers

Snowmass Village, CO

Assessment of structural safety requires knowledge of the shape of any defect and the stresses acting on it. Ultrasonics can be used to measure applied stress since there is a (small) change in velocity with stress. However the problem becomes more difficult when measuring residual stress. Here the influence of other factors such as variation in microstructure must be accounted for. For example, one method is to measure the percent difference in velocity of orthogonally polarized shear waves (the acoustic birefringence B). When the material symmetry and stress axes coincide [1], B=Bo+CaD where Be is the birefringence in the unstressed state, Ca is the acoustoelastic constant and D is the difference of principal stresses. The usual procedure is to measure B at a “reference” location where stresses are known, and assume homogeneity of microstructure.