A dynamic calibration method of free-field pressure sensor based on Hopkinson bar

Wen Liang,Yuwu Zhang,Rong Chen

doi:10.1063/5.0008383

Abstract

This paper presents a dynamic calibration method for the dynamic sensitivity coefficient of a free-field pressure sensor working in liquid. In this method, an oil-filled auxiliary tool has been designed and the free-field pressure sensor sealed in the tool was loaded by a Hopkinson bar that could generate a stress wave with known amplitude. The strain signal of the Hopkinson bar and the output signal of the sensor were collected and processed based on the Hopkinson experimental principle and the dynamic sensitivity coefficient of the sensor was calibrated. A calibrated PCB W138A10 pressure sensor was re-calibrated and its dynamic sensitivity coefficient was obtained. Compared with the parameters from the calibration certificate of this sensor, this experimental result is reliable. This method can obtain the more accurate result and can be widely used in the dynamic calibration of free-field pressure sensors that work in liquid.

Highlights

Various explosive or ballistic loadings have a common feature, i.e., the motion parameters change significantly on a relatively short time scale.1 In this case, the mechanical performance of the material is significantly different from that in the case of static loading.2 When we evaluate the damage effect of underwater weapons by measuring the pressure in water, we need a free-field pressure sensor after dynamic calibration, not just static calibration, because the sensitivity coefficient of the pressure sensor may change as the loading frequency increases.A dynamic pressure signal generator is required when the pressure sensor is dynamically calibrated
Periodic pressure generators can directly obtain the frequency response of the sensor, but at the same time, they obtain higher amplitude and steady frequency with a great difficulty, so they are not suitable for the calibration of the dynamic sensitivity coefficient of the free-field pressure sensor working under higher pressure
The pressure of the shock wave front can be estimated by measuring the speed of the shock wave propagating in the ideal gas, which causes a large error

Summary

Introduction

Various explosive or ballistic loadings have a common feature, i.e., the motion parameters change significantly on a relatively short time scale. In this case, the mechanical performance of the material is significantly different from that in the case of static loading. When we evaluate the damage effect of underwater weapons (such as torpedoes and deep-water bombs) by measuring the pressure in water, we need a free-field pressure sensor after dynamic calibration, not just static calibration, because the sensitivity coefficient of the pressure sensor may change as the loading frequency increases.A dynamic pressure signal generator is required when the pressure sensor is dynamically calibrated. Various explosive or ballistic loadings have a common feature, i.e., the motion parameters change significantly on a relatively short time scale.. When we evaluate the damage effect of underwater weapons (such as torpedoes and deep-water bombs) by measuring the pressure in water, we need a free-field pressure sensor after dynamic calibration, not just static calibration, because the sensitivity coefficient of the pressure sensor may change as the loading frequency increases. Periodic pressure generators (such as piston-in-cylinder and rotating valve4) can directly obtain the frequency response of the sensor, but at the same time, they obtain higher amplitude and steady frequency with a great difficulty, so they are not suitable for the calibration of the dynamic sensitivity coefficient of the free-field pressure sensor working under higher pressure.. This calibrated reference sensor still needs other calibration methods, so it cannot solve the problem from the source

Methods

Results

Conclusion