SU953514A1 - Device for material sample small-cycle testing - Google Patents

Description

one

Iaofetenenne refers to a testing technique, namely, devices for testing samples of materials.

 A device for testing samples of materials, containing a frame, grippers for placing a test sample in them, a sample Mort, an automatic reverse-drive drive, kinematically connected to one gripper and installed naram, load sensors and de fg formalin associated with the corresponding grips, first and the second bridge circuits, the shoulders of which include load and strain sensors, a voltage divider and a potential-s-meter C1, respectively.

The disadvantage of the device is the impossibility of conducting low-throughput tests of samples with a constant width of the elastoplastic hysteresis loop.

The most technically advanced invention of the invention is a device for low-cycle testing of material samples, which contains a frame, an actuator mounted on it, a reversal control unit connected to it, a fixed and movable grippers for accommodating an Ofotz and a deformometer associated with it, the first the second strain gauge, mounted respectively on the fixed gripper and deformometer, and an automatic compensator, including registration means, the output of which is connected to the input of the reversal control unit 2

The device allows low-cycle testing under both soft and hard loading conditions.

The disadvantage of the device is the impossibility of carrying out tests at constant igarin of the elastoplastic hysteresis loop, which reduces the accuracy of the results obtained.

Claims (1)

The purpose of the invention is to increase accuracy by allowing low-cycle tests at 39. constant width of the elastoplastic hysteresis loop. This goal is achieved by the fact that the device is equipped with first and second bridge circuits whose measurement diagonals are connected counter, a voltage divider connected to the OUTPUT of bridge circuits and the input of the automatic compensator, and the first and second resistance strain gages are respectively included in the shoulders of the same name bridge circuits. FIG. 1 is a block diagram of the device; in fig. 2 - electrical device diagram. The device for low-cycle testing of specimens contains a frame 1, a drive 2, a fixed grip 3 rigidly connected to frame 1 and a movable grip 4 for placing sample 5, tensor switches 6 and 7, deformometer 8, divider 9, first and second circuits 10 and 11, each of which contains sources 12 and 13 of the power supply and the resistance strain gages 6 and 7 that are included in the corresponding bridge schemes 1O and 11, the strain gages 14 and 15 of temperature compensation and the set resistance 16, 17 and 18, 19. The bridge circuits 10 and 11 are connected to a divider 9 to automatic compensator 20, in which quality A two-coordinate electronic potentiometer is used, which includes two microswitches 21 and 22. These are used to control the measured value. The device also contains a movable carriage 23 and a reverse control unit (not shown in the diagram). Microswitches 21 and 22 are included in the control circuit of drive 2 and switch reverser when the specified difference in the signals produced by the outputs of bridge circuits 1O and 11 is reached. The device also contains equipment for heating the sample and maintaining its temperature mode (in the drawing shown). The device works as follows. When the actuator 2 is turned on, the movable gripper 4 moves, creating in the sample 5 elastoplastic deformations of the stretch. In this case, in the bridge circuits 10, 11, an emf of opposite signs is induced, proportional to the needle, respectively, to the elastic deformations of the fixed gripper 3 and, consequently, sample 5 and the elastic-plastic deformation of the sample 5. Divider 9 allows choosing the emf of the bridge circuit Yu so that The elastic strain of the specimen difference of the emf of bridge circuits 10 and 11 was zero. In the field of elastoplastic deformation, the splitter 9 is fed to the automatic compensator 2O and a differential signal is proportional to the plastic deformation of sample 5, i.e. loop width of an elastoplastic hysteresis. When the set value of the differential signal is reached, the carriage 23 will close one of the microswitches 21 or 22 and reverse the drive 2, and the sign of the load will change. The device allows operation under both soft and hard loading conditions. In order to implement a soft loading mode, the bridge circuit 11 is turned off and the bridge circuit 10 is connected to the input of the compensator 20, the output of which produces a signal proportional to the voltage of the sample 5. With a hard immersion of the sample 5, the bridge circuit 1O is disconnected and the bridge circuit 11 is connected to an automatic coil protector 2Og to which a signal is given, proportional to the elastic-plastic deformation. The invention makes it possible to test samples of materials at a constant width of the elastoplastic hysteresis loop, which improves the accuracy of determining the strength characteristics of materials. The invention of the Device for low-cycle testing of material samples, comprising a frame, an actuator mounted thereto, a reverse control unit connected thereto, a fixed and movable grippers for accommodating an OFZ and a deformometer associated therewith, the first and second strain gauges mounted respectively on the fixed clamp and a deformeter, and an automatic compensator, including registration means, the output of which is connected to the reverse control input, characterized in that, in order to increase the accuracy In order to enable low-cycle testing with a constant elongation of the elastoplastic hysteresis loop, it is equipped with the first and second MocTonHN circuits, the measuring diagonals of which are included counter, de. NEP Jo