Clip gage attachment
Abstract
Studies were conducted to determine the effect of adhesive bond and pin attachment of instrumented clip gages for propellant strain measurements. Finite element analysis of the adhesive attachment shows large stress concentrations at the adhesive edge and large disturbance of the overall stress field. This stress field was disturbed enough to cause a 20 percent change in the effective gage length for the clip gage. Experimental measurements confirmed the 20 percent error in the electrical strain measurements. Clip gage forces of 30 grams caused over 20 percent relaxation effects which were considered excessive. Clip gage designed were also tested which exerted less than 10 grams of force on the propellant which yielded more acceptable strain measurements. Small diameter pin attachments were studied as an alternative to the adhesive bonded designs and had some advantages in reducing both stress disturbance and relaxation effects.
- Publication:
-
The 23rd JANNAF Combustion Meeting, Volume 1
- Pub Date:
- August 1986
- Bibcode:
- 1986jann.conf...87T
- Keywords:
-
- Adhesive Bonding;
- Clips;
- Mounting;
- Pins;
- Solid Propellant Rocket Engines;
- Solid Rocket Propellants;
- Strain Gages;
- Strain Measurement;
- Stress Measurement;
- Stress Concentration;
- Stress Distribution;
- Stress Relaxation;
- Instrumentation and Photography