Development of a Normal Shear Stress and Temperature (NSST) Sensor Calibration Rig
Abstract
Development of shear stress sensors for solid propellant rocket motors was attempted in the early 1970s. The sensors needed large strains in the sensing elements to obtain sufficiently high signal-to-noise ratios for the foil strain gages that were used. With the availability of high performance semiconductor strain gages, it is possible to design not only a compact shear stress sensor, it is possible to design a sensor that can simultaneously measure the shear and normal stress components acting on a solid rocket motor bondline. The objective of this study is to design a calibration rig for a diaphragm-based normal shear stress and temperature (NSST) sensor. In this report, the design of a milling machine type NSST calibration rig is presented. Preliminary tests evaluating the ability of the calibration rig to apply pure normal and pure shear to the NSST sensor show that the calibration rig applies the loading boundary conditions to the NSST sensor in a manner that is consistent with the boundary conditions used in the NSST sensor finite element analysis. Moreover, the experimentally measured NSST normal and shear bridge outputs were comparable, in relative magnitude, to the predicted NSST normal and shear bridge outputs thereby validating the modeling technique employed and the results obtained in the finite element analysis. Four prototype NSST sensors were built. Three of the prototype sensors were calibrated using the NSST calibration rig. The calibration results are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 24, 2020
- Accession Number
- AD1128066
Entities
People
- Franklin C. Wong
- James M. Fillerup