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Experimental Mechanics

, Volume 17, Issue 11, pp 415–419 | Cite as

Measuring small internal pressures along a tube during steady flow

Equiangular strain-gage rosettes aligned as stress-gage pressure transducers measured the small strains and pressures along a thin-walled aluminum tube during extrusion of a viscous silicone oil
  • H. S. FreynikJr.
  • G. R. Dittbenner
Article
  • 44 Downloads

Abstract

A tube that can accurately measure small strains and pressure profiles during flow of non-Newtonian paste explosives has been designed and strain gaged. Equiangular rosette strain gages were installed along the length of a 6-mm-diam, 0.46-m-long thin-walled aluminum tube. The rosettes were oriented in the classical stress-gage configuration to measure circumferential stress and, hence, internal pressure independent of other stresses.

The tube was static calibrated on a floating-piston pressure calibrator. Steady flow calibration was accomplished by extruding a viscous Newtonian silicone oil. Inlet pressure ranged from 0.52 to 2.1 MPa (75 to 300 psi). For the low-pressure 0.52-MPa silicone-oil extrusion, the full-scale strain levels varied from 6 to 53 μm/m. For all eight strain-gage stations, the maximum deviation from a linear pressure profile was equivalent to 0.5 μm/m. A pulsed-current-excitation signal-conditioning and digital data-acquisition system provided the necessary stability and precision to measure these unusually low-strain levels accurately.

Keywords

Internal Pressure Steady Flow Pressure Profile Inlet Pressure Circumferential Stress 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Society for Experimental Mechanics, Inc. 1977

Authors and Affiliations

  • H. S. FreynikJr.
    • 1
  • G. R. Dittbenner
    • 1
  1. 1.Lawrence Livermore LaboratoryUniversity of CaliforniaLivermore

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