Good Morning,
I am looking in NDT test such as ultrasound in bituminous mixtures, which is a special materials with viscoelastic behavior, this viscosity provide a delay between force applied and deformation response. creating a complex behavior expressed in complex modulus
Most ultrasound test in elastic construction materials such as concrete which make the Wave Propagation (W.P) less complex and more simple. some research propose a different formula for P and S wave propagation in bituminous materials
So i am looking for physicist who can explain me the different between W.P in both materials (concrete VS bituminous mixture)
Dear Mohammed,
certainly the viscoelastic effect is a complex issue when testing with ultrasound. The viscoelastic material will produce attenuation of the ultrasonic waves, regardless if they are P or S-waves. You may need to do quasi-elastic testing over time in order to get an estimate of the behaviour. There are some studies and simulations here:
Conference Paper Ultrasound propagation in viscoelastic material guides
Also it has been shown that there is a correlation between mode coupling, by gradual variation of the imaginary parts of the viscoelastic moduli, and the material viscoelasticity. Most of these studies use air-coupled transducers, or laser-based ultrasound.
Hope this helps.
Hi Mohammed - It's quite difficult working with viscoelastic materials e.g, bitumen at ultrasonic frequency (small band). Frankly, you can not extract too much of the information. Look at this paper for shear wave reflection from bitumen (and references within)
Article Ultrasonic shear wave reflectometry applied to the determina...
I've another paper in press that in fact discusses the ultrasonic P-wave propagation through bitumen. It talks about the complex modulus of bitumen.
Hope this helps!
Thanks
I suggest you to look for other testing methods like shearography for viscoelastics.
- Badges
- Science topic