Understanding the mechanical properties of diaphragms is crucial for the reliability and performance of Nano Electro Mechanical Sensors (NEMS). There are various methods documented for characterizing micro materials. One well-established nondestructive approach is the bulge test, which is effective for examining the mechanical traits of diaphragms. This study aims to enhance NEMS performance by exploring how a Nano rectangular diaphragm (NRD), created from a new material within NEMS, behaves mechanically through an improved bulge test technique. The NRD is made from layers of basalt fiber reinforced polymer (BFRP) laminate composites, sized at the nanoscale, and was tested at room temperature for plane-strain bulging. Before applying any loads, the NRD is pre-stressed to eliminate any initial deflection and then securely clamped between two plates. A differential pressure is applied, causing deformation in the laminated composite NRD. This setup makes the plane-strain bulge test well-suited for analyzing the mechanical properties of the laminated composite NRD in both elastic and plastic states. We derived an exact solution to the governing equations for the symmetric cross-ply BFRP laminated composite NRD, taking into account the impact of residual strength from the pre-stressed condition. The relationship between stress and strain for the BFRP laminated composite NRD was determined through hydraulic bulging tests, and we analyzed the gradual thickness changes at different points of the hemisphere formed during the bulge test. We can also extend a finite element model (FEM) to analyze the BT outcomes and look into how pre-stress influences the pressure testing, comparing results from the FEM with those derived from analytical calculations. The relative error (E_r) for w_max between the analytical and numerical results is less than 0.336%. We ran simulations using ANSYS, MATLAB and its PDE toolbox to get our results.

Under thermo-mechanical stress via a bulge test (BT), composite circular diaphragms (CCD) exhibit temperature-dependent mechanical behavior, including changes in Young’s modulus, yield strength, and residual stress. The application of a differential pressure and temperature causes the membrane to deform, allowing researchers to characterize composite material properties, particularly for materials used in microelectromechanical sensors (MEMS) operating in harsh environments. This paper aims to explore how CCD made from basalt fiber reinforced polymer (BFRP) behaves under thermal and mechanical stress, particularly in various engineering and bioengineering sensor applications, using a technique known as the BT. To start, the diaphragm is pre-stressed and clamped between two plates. When applying differential pressure, it causes the diaphragm to deform. An analytical approach is developed for utilizing the BT to describe the thermo-mechanical properties of these diaphragms. This method is well-suited for examining how diaphragms behave mechanically in both elastic and plastic states. A finite element model (FEM) is extended to analyze the BT outcomes and look into how pre-stress influences the pressure testing, comparing results from the FEM with those derived from analytical calculations. The variations in thickness and material type are also taken into account to better understand how they affect the diaphragm’s mechanical behavior under stress. Additionally, this work considers how temperature impacts the material properties of the diaphragm, which is crucial for analyzing its thermo-mechanical response. The relative () for maximum deflection the analytical and numerical results is less than 0.3%. The simulations are done using ANSYS, MATLAB and its PDE toolbox to get the results.