According to the need of laboratory study of the generalized stress relaxation characteristics of rock

an experimental system of uniaxial tension servo control

which is based on stress feedback take hardware devices as basis and transforms data recording and servo controlling to achieve the stress feedback method

is developed. The advantages of the uniaxial tensile test system are as follows: (1) The system can realize the stress feedback

except carry out the traditional displacement control and stress control of the load alone

also stress-strain linear combination of servo control. (2) The measurement system and control system are realized by hardware rather than computer software; the structure is simple and compact; the reaction time of the system action is short; the performance is stable and reliable; the space of upgrading is large. (3) The control and monitoring data use simulate signal transmission and the test process control and data acquisition accuracy are higher. (4) By using high strength adhesive

the specimen is in the state of tension; and the stress state of rock mass can be simulated in real engineering. Using this system

the generalized relaxation test of tage tuff under tensile stress has been accomplished

and the test results show that the device has good practicability and reliability

so as to provide a new method and means for studying the mechanical properties of generalized stress relaxation under the action of tensile stress of rock in engineering practice.