Volume 34, Issue 2 (March 2006)
Control of Noise and Specimen Temperature During 1 kHz Fatigue Experiments
Both sound-proofing and sound-conditioning methods were employed in the construction of a sound-insulation room to house a 1 kHz servohydraulic fatigue testing machine to protect researchers from excessive noises caused by the running machine. The “box inside a box” construction and acoustical foams were used to improve the sound insulation of the room. Special attention was paid to a door, a window, and cable holes. In addition, the specimen self-heating effect during a high-frequency fatigue experiment was found to influence the fatigue life of materials. The specimen temperature in air during fatigue tests at 700 Hz is much higher than at 10 Hz. The fatigue resistance was lessened by a higher specimen temperature. A cooling method using nitrogen gas was employed to control the specimen temperature during fatigue testing. The fatigue lives of specimens in air were generally longer for the tests conducted at 700 Hz with cooling using nitrogen gas, as compared to those without cooling, and were comparable with those at 10 Hz in air.