Sensitivity of Stiffness and Damping to Various Aspects of Material and Structural Behavior

Abstract

This paper reviews research which has demonstrated the use of nondestructive measurements of stiffness and damping to characterize some interesting aspects of both micromechanical and macromechanical behavior in materials and structures. The sensitivity of stiffness and damping to material microstructural detail, macroscopic defects and damage, degradation due to environmental conditions such as temperature and moisture, and other mechanical properties is examined. Observed changes in stiffness and damping can be particularly useful when measured by using nondestructive vibration tests, and there are potential applications of such measurements in both manufacturing quality control and in-service evaluation of materials and structures. A particularly attractive method for fast, low cost nondestructive measurement of stiffness and damping is based on the use of impulsive excitation, non-contacting response measurement, and data analysis with PC-based virtual instruments.