Material Evaluation. Part I. Mechanical Property Testing and Materials Evaluation and Modeling.

To accomplish the assessment of the characteristics of materials which are currently being used or which may be used in airframes and in gas-turbine engines, the following three tasks were performed--development and implementation of mechanical test methods, research on the application of solid mechanics to failure prediction, and investigation of environmental effects upon mechanical behavior. Some of the test methods which were developed in the first task were a low-cycle-fatigue LCF test capability, an experimental set-up to evaluate crack growth under sustained load, and a capability to conduct crack-growth tests under spectrum loads. In these tests the temperature range was normally between 538 C 1000 F and 760 C 1400 F, and the specimen geometries were uniform gage specimens for the LCF tests, compact-type CT specimens for the sustained-load crack-growth tests, and CT and wedge-opening-loaded WOL specimens for crack-growth tests under spectrum loads. The tests which were conducted on material behavior provided data for at least 30 reports and journal articles. These tests, in addition to the previously developed tests, included uniaxial tension and compression tests, creep tests, fatigue-life tests, and single and multiple overload and underload tests. The temperature range for these tests was between room temperature and 760 C 1400 F. Equipment and instrumentation which were designed and fabricated for these tests included resistant furnaces, induction coils, d.c. conditioners, and power controllers.