Tensile testing machine is used to carry out static load, tensile, compression, bending, shearing, stripping and other mechanical properties of the material with mechanical testing machine, suitable for plastic sheet, pipe, profile, plastic film and rubber, wire and cable materials of various physical and mechanical properties testing for material development.
Tensile testing machine operating procedures:
1. Preparation of the specimen: The tensile testing machine takes the mark distance in the middle of the specimen or uses the foot mark gauge at both ends of the mark distance to punch the eye as a mark, and uses the vernier caliper to measure the center and the diameter at both ends and three places within the limit of the mark distance of the specimen to take the minimum value as a calculation of the cross-section area of the specimen.
2, the preparation of tensile testing machine: first investigate the fundamental structure of the data testing machine and operation methods, and learn the operating procedures of the testing machine. According to the strength limit of low carbon steel and the cross-sectional area of the specimen, the maximum load required for the tensile specimen is preliminarily estimated, the appropriate measuring force plate is selected, and the response pendulum is equipped with the motor opener, the force pointer is adjusted to “zero”, and then the position of the chuck under the testing machine is adjusted, and the specimen is installed in the chuck.
3, the implementation: after the specimen is clamped, the specimen is slow and average loaded, and the test machine is actively drawn and installed to draw the relationship between external force and deformation. When the load is added to the point of the tensile diagram, the straight line indicates the proportional relationship between the load and the variable composition of the specimen in this stage, that is, the elastic deformation limitation in line with Hooke’s law.
After the activity stage, the specimen must accept greater external force, and the deformation can continue to occur. If the plastic deformation is increased, the load must be added, such as the section from the middle point to the point of the figure for the strengthening stage.
When the load reaches the maximum point, the plastic deformation of the specimen is concentrated in a small section at a certain section, and the section of this section is shortened, that is, showing a “neck contraction” scene.
Close the machine, take off the broken specimen and tighten the broken specimen together, measure the length between the test pieces after breaking with the vernier caliper, and calculate the extension rate of low carbon steel by pressing the formula below.