Gray, Edward I.
Project Engineer, Allied Research Associates, Inc., Boston, Mass.
Research Engineer, Allied Research Associates, Inc., Boston, Mass.
Rubin, Melvin R.
Staff Engineer, Allied Research Associates, Inc., Boston, Mass.
Pages: 8 Published: Jan 1958
Recent investigations on the thermal behavior of aircraft structures undertaken for the Wright Air Development Center by Allied Research Associates, Inc., included a series of laboratory tests on the Baldwin-Lima-Hamilton Nichrome V foil high-temperature strain gage, type HFN-3. The test results indicated that biaxial strain conditions make it impractical, for high-intensity transient thermal loading of aircraft structures, to attempt compensation for the effects of temperature on strain gage readings by the use of a temperature-compensating dummy gage. Therefore, a temperature-compensation calibration curve was prepared for the Nichrome V foil gage. For this purpose, thermal strain data were compiled with this gage bonded to a free aluminum plate. Temperature-compensated data taken from similar gages mounted on a simple cantilever aluminum strip subjected to combined mechanical and thermal inputs were then compared with the strain measurements obtained by the free-plate method with favorable results. Sufficient data were obtained to permit the construction of a calibration curve for application of this gage bonded to other metals as well. The results of these tests are presented graphically accompanied by a brief description of the experimental procedure.
Paper ID: STP45031S