Fatigue test bench SCC

constant loadstress testcomputer-controlled

The SCC instruments of Advance Instrument (AI) are computer controlled,electromechanically operated loading devices. The loading unit can perform SSRT tests, constant load tests and cyclic fatigue tests. It is for the investigation of various forms of Stress Corrosion Cracking (SCC) under different environmental conditions. The system consists of the loading units, datum acquisition unit, control system and the test vessel. The facility is designed for Constant Load Testing (CL), Slow Strain Rate Testing (SSRT) and Low Cycle Fatigue Testing (LCF). The computer controls a motor that is loading the tensile specimen. The displacement rate is specified by the operator’s computer software. The measured value from the load cell will be displayed on the computer screen by means of the software. The computer saves both the displacement and load data automatically. The data will be available for further management in ASCII format. The instrument fulfills the requirements presented in ASTM Practice G 129. When constant load feature is used, the response of the load cell is used as a feedback signal to control the displacement so that the load cell measurement value is equal to the load set by the operator. The loading device can perform low frequency cyclic fatigue tests. The cyclic loading can be performed either under load or strain control. The shape of the loading can be either of trapeze (a special case: saw tooth) or sinusoidal type. The maximum frequency depends on the amplitude. The basic design of the unit includes a compact non-backlash ball screw driver actuator, with the motor, and a load cell with a digital force indicator.