Numerical analysis of stainless steel diaphragm for low pressure measurement

Abstract

Metal membranes are the thin circular plates. For transducers and pressure transmitters, it is assumed that the membrane is loaded with uniform load over the entire surface. In case that the membrane is rigid over the edge, then it is called a diaphragm. In general, the membranes are divided into flat and corrugated. Corrugated diaphragms can resist much higher pressure than flat diaphragms and they are used mainly in the low pressure area. In contact with various aggressive fluids, membranes are most commonly made of high alloy austenitic steel, which have high corrosion resistance, have good spring properties and they are stable at different temperatures. The deflection analyses of corrugated diaphragms are very important in sensitivity of transducers/transmitters. The application of corrugated diaphragms gives possibility to control sensitivity of thin diaphragms by geometrical parameters. In this paper numerical and experimental structural analysis of a thin corrugated diaphragm 19 mm diameter, with variable material thickness and corrugation number is presented. Experimental tests are conducted on a corrugated stainless steel (AISI 316) diaphragm. The measured deflections are compared with numerical results in ANSYS software package. The results showed small deviations between numerical and experimental data, which is very important for further diaphragm application of measurement instruments.