Under the premise of small deformation of a material tensile testing machine, the strain at a certain point of an elastic element is proportional to the force on the elastic element, and it is also proportional to the elastic deformation. Taking a sensor as an example, when the sensor is subjected to a tensile force, because a strain gauge is attached to the surface of the elastic element, the strain gauge is connected to the measurement circuit, and then the output voltage can be measured, and then the magnitude of the force can be measured.

 

The operation of the material tensile testing machine is a system that controls the operation of the testing machine. The status of the testing machine and various experimental parameters can be learned through the display screen. If the machine is equipped with a computer, the computer can also complete various functions and perform Data disposition analysis, test result printing. The communication between the testing machine and the computer generally uses the RS232 serial communication method. It communicates through the serial port (COM number) on the back of the computer. This skill is relatively sophisticated, reliable, and easy to use.

It is mainly used for the movement of the beam of the testing machine. The working principle is that the servo system controls the motor. The motor uses a series of transmissions such as a reduction gear box to organize the movement of the screw rod and then reaches the intention of controlling the movement of the beam. By changing the speed of the motor, the moving speed of the beam can be changed.

 

Generally speaking, the output signal of the sensor is very weak, generally only a few mV, if we directly measure this signal, it is very difficult, and can not meet the needs of high-precision measurement. Therefore, it is necessary to expand this weak signal through an amplifier. The expanded signal voltage can reach 10V. The signal at this moment is an analog signal. This analog signal is converted into a digital signal by a multiplexer and an A / D conversion chip, and then the data is processed. At this point, the force measurement comes to an end.

 

Through deformation measurement, it is used to measure the deformation of the sample during the experiment. The device has two chucks, which are connected to the photoelectric encoder mounted on the top of the measuring device through a series of transmission tissues. When the interval between the two chucks changes, the axis of the stranded photoelectric encoder rotates and the photoelectric coding Will have a pulse signal output. Then the single-chip microcomputer processes this signal to obtain the deformation of the sample.