Multivariable Regression Approach for Porosity Determination in Composite Materials

The porosity content in composite material is known to innuence the strength of the material. It is therefore of interest to monitor the porosity contents during manufacturing. Since attenuation and porosity are related, traditional porosity determination in composites is performed as attenuation measurements using ul-trasonic tone burst through-transmission. In this paper we propose a multivariable regression approach for estimating ultrasound attenuation in composite materials by means of pulse-echo measurements, thus overcoming the problems with limited access that is the main drawback of through-transmission testing. The result from the work shows that we can obtain good approximations of the attenuation values using pulse echo ultrasound. This indicates that it will be possible to replace the through-transmission technique by a pulse echo technique.