Three-component strain gauge for precise measurement of load fluctuations

Abstract

The aim was to assess the loading of large-size elements of machine structures using versatile strain gauges. A strain gauge was developed using a system analysis of failures and deficiencies in the manufacture and operation of large-scale structures, strain gauging, strength of materials methods, as well as the theory of elasticity of ring elastic elements. The ANSIS software package was used to calculate rational sensor parameters. The conducted study of ring elastic deformation (determination of stiffness and stress-strain state) allowed the authors to propose that the ring shape should be replaced by an octahedral polygon. This form is suitable for mounting strain gauges for simultaneous measurement of tension and compression, as well as bending and torsion, i.e., forces arising in a machine structural element or in the manufacture of large-size surfaces. The obtained results were used to derive dependences to determine the measurement error of the gauge under study. A comparative analysis of ring and octahedral gauges identified unique features of the latter, consisting in the possibility of assessing the measured values along the three coordinate axes with a high degree of accuracy. The conducted research shows that the proposed strain gauges are capable of registering the magnitude and fluctuations of loads with a high measurement accuracy. The proposed scheme of gauge placement makes it possible to determine the vertical and horizontal components of the forces arising in a structural element and to assess deviations in the process of measurement. In addition, the proposed measuring scheme minimizes the error of mutual influence of sensors. The developed force meter is a versatile device that can be used for registering static and dynamic impacts, as well as for digital control of force parameters in the range of up to 5 mm.