1. The force value of the tensile testing machine is measured through a load cell, amplifier and data processing system. It is known from material mechanics that under the premise of small deformation, the strain ε at a certain point of an elastic element is proportional to the force on the elastic element, and also proportional to the elastic deformation. Taking the S-type testing machine sensor as an example, when the sensor is subjected to a tensile force P, since a strain gauge is attached to the surface of the elastic element, and the strain of the elastic element is proportional to the magnitude of the external force P, the strain gauge is connected to the measurement circuit, and its output voltage can be measured, and then the force can be measured.
2. The deformation is measured through a deformation measuring device, which is used to measure the deformation of the sample during the experiment. There are two chucks on the device, which are connected to the photoelectric encoder installed on the top of the measuring device through a series of transmission mechanisms. When the distance between the two chucks changes, the shaft of the photoelectric encoder is driven to rotate, and the photoelectric encoder will output a pulse signal. This signal is then processed by the processor, and the deformation amount of the sample can be obtained.
3. The principle of measuring the beam displacement is roughly the same as the deformation measurement. The displacement of the beam is obtained by measuring the output pulse number of the photoelectric encoder.
