Engineering topics

Moore, T. C.

Publications and source records attributed to Moore, T. C..

3 records

NASA NTRS1984

Strain gage calibration

A temporary bonding system for accurately predetermining the individual apparent strain curve characteristics of the gages is used, and subsequently employs a computer to watch the apparent strain curves of the individual gages to determine which gages should be used together on transducers. The temporary bonding system requires a test block on which the gages are temporarily bonded, several thermocouples for monitoring temperature, and a data acquisition system for recording apparent strain data. Initially, a group of strain gages are attached to the test block using a bonding agent that disintegrates at high temperatures. The gages are then wired to an appropriate data acquisition and data, collected throughout a predetermined temperature excursion. Once the data is obtained, the test block is heated until the bonding agent disintegrates freeing the gages from the test block. The gages are then disconnected from the data acquisition system and cleaned, thereby ready for use on transducers.

Moore, T. C.↗

NASA NTRS1982

Matching of Apparent-Strain Characteristics

Strain gages are temporarily bonded to surface of test block. Apparent strain is recorded in excursion to -190 degrees C, and gages are disbonded following heating to elevated temperature. Matching strain gages for cryogenic use has several advantages. Initial accuracy for cryogenic transducers is greatly improved, less apparent-strain correction wire is required and there are smaller errors due to loop data caused by long pieces of correction wire.

Moore, T. C.↗

NASA NTRS1981

Force instrumentation for cryogenic wind tunnels using one-piece strain-gage balances

Materials and techniques for a transducer capable of obtaining accurate force measurements at cryogenic temperatures (down to 77 K) and high pressures (up to 9 atm) have been determined. Areas of high stress concentration are minimized by balance design, and model and sting attachment methods able to withstand cryogenic temperatures are used. Maraging 200 is the material used for the balances, due to its high impact strength and simple heat treatment procedure. Test results verify that the balances produce reliable, repeatable, and predictable data from 300 K to 110 K under steady state conditions. Techniques have been developed to reduce the temperature-induced bridge output, such as the use of bridges with two gages mounted transverse to the principal stress direction. Under these conditions, the results given by the balances should be equally good during transient temperatures on five of the six components. The work will be used at the National Transonic Facility (NTF) at NASA Langley.

Ferris, A. T.↗