A Novel Methodology to Obtain the Mechanical Properties of Membranes by Means of Dynamic Tests

Abstract

A new, non-destructive methodology is proposed in this work in order to determine the mechanical properties of membrane using vibro-acoustic tests. This procedure is based on the dynamic analysis of the behavior of the membrane. When the membrane is subjected to a sound excitation it responds by vibrating based on its modal characteristics and this modal parameter is directly related to its mechanical properties. The paper is structured in two parts. First, the theoretical bases of the test are presented. The interaction between the sound waves and the membrane (mechano-acoustic coupling) is complex and requires meticulous study. It was broadly studied by means of numerical simulations. A summary of this study is shown. Aspects, such as the position of the sound source, the measuring points, the dimensions of the membrane, the frequency range, and the magnitudes to be measured, among others, were evaluated. The validity of modal analysis curve-fitting techniques to extract the modal parameter from the data measures was also explored. In the second part, an experimental test was performed to evaluate the validity of the method. A membrane of the same material with three different diameters was measured with the aim of estimating the value of the Young’s modulus. The procedure was applied and satisfactory results were obtained. Additionally, the experiment shed light on aspects that must be taken account in future experiments.

State of the Art Membrane Science and Technology in the Iberian Peninsula 2021–2022

“…This last paper is certainly more related to membrane characterization, a field in which Spanish researchers have traditionally been very active, as can be seen in the Membrane Groups directory included in the Spanish-side review [ 1 ]. In this area, Lima-Rodríguez et al [ 13 ] proposed a novel method for the non-destructive study of the mechanical properties of membranes. This procedure was based on the use of vibro-acoustic tests and the dynamic analysis of the behaviour of the membrane to these vibrational sound waves.…”

“…Rita et al [16] explored the use of membrane filtration to treat spent caustic effluents from Sines Refinery, in Portugal. These effluents are very challenging due to their very hazardous nature in terms of toxicity (rich in mercaptans, sulfides and other aromatic compounds) as well as their extreme pH (approximately [12][13][14]. The potential of nanofiltration (NF) polymeric and ceramic membranes was assessed by membrane life expectancy.…”