FREQUENCY DEPENDENCES OF COMPLEX MODULI AND COMPLEX POISSON'S RATIO OF REAL SOLID MATERIALS

✍ Scribed by T. Pritz

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 270 KB
• Volume: 214
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1534

✦ Synopsis

The concept of a complex modulus of elasticity is a powerful and widely used tool for characterizing the linear dynamic elastic and damping properties of solid materials in the frequency domain. It is shown in this paper that typical characters of frequency dependences of all complex moduli (shear, Young's etc.), and complex Poisson's ratios of real solid materials can be determined by transforming the causal and real relaxation and creep responses, respectively, from the time-domain into the frequency domain, even without having to specify the processes of relaxation and creep. It is proved that all dynamic moduli monotonically increase, and the dynamic Poisson's ratio monotonically decreases with increasing frequency, and all respective loss factors pass through at least one maximum. These frequency dependences are generally valid for any real solid material regardless of the actual damping mechanism. Some experimental results are presented and interepreted in the light of the theory. The usefulness of theoretical predictions in materials engineering, measurements of dynamic properties and in modelling dynamic behaviour is discussed.