Modelling and non-destructive measurement of dispersion behaviour of stainless steel and alumina ceramic porous plates

Abstract Porous materials contain a network structure composed of distributed pores. Due to the distribution of pores, the volume of the material will be less than the actual dense volume. The material coefficients such as density and elastic modulus can change due to the influence of porosity. Therefore, the characteristics of porosity can be used as a measurement standard in the properties detection. This study explores the dispersion relationship of the wave propagation behaviour of the Lamb wave of porous material plates such as 316 L stainless steel and permeable alumina ceramic with different porosities in water fluid environment. We used laser to excite the ultrasonic wave and used probe receiving as a method to measure the guided wave dispersion relationship. The results of the study show that the effect of porosity of the porous plate on the density and elastic modulus can be shown through the dispersion relationship. The theoretical model and the experimentally measured dispersion relationship results were in good agreement. In addition, by altering the density, Poisson's ratio, shear modulus and independent porosity of the porous plate, the dispersion curve can be shifted, which can be used for the development of ultrasonic measurement in the future.