Views: 191 Author: Site Editor Publish Time: 2019-04-25 Origin: Site
The tensile testing machine is also known as the universal material testing machine. The universal testing machine is a mechanical augmenting test machine for testing the mechanical properties of equipment, such as static load, tensile, compression, bending, shearing, tearing, peeling, etc., for plastic plates, pipes, Various physical and mechanical properties of materials such as profiled materials, plastic film and rubber, wire and cable, steel, glass fiber, etc. are developed for materials, and are indispensable testing equipment for physical property testing, teaching research, quality control, etc. Important components, different materials require different fixtures, and it is also an important factor in whether the test can be carried out smoothly and the accuracy of the test results is high.
Widely used in metrological quality inspection; rubber plastics; metallurgical steel; machinery manufacturing; electronic appliances; automobile production; textile chemical fiber; wire and cable; packaging materials and food; instrumentation; medical equipment; civilian nuclear energy; civil aviation; colleges and universities; Laboratory; commodity inspection and arbitration, technical supervision department; building materials ceramics; petrochemical; other industries.
First, according to the degree of automation can be divided into
1. Pointer type tensile testing machine: This traditional type of tensile testing machine has been basically eliminated by the digital display tensile testing machine due to its low test accuracy and low cost performance. However, in the small power range, it is our common dynamometer, which is often used by factories for simple strength testing of small products. Because of its low price, it is still very popular.
2, digital display tensile testing machine is also called micro-computer type tensile testing machine: the test data is directly displayed on the LCD screen, the test items are relatively fixed, and are often used for quality control of the factory.
3, computer system tensile testing machine: is the most common tensile testing machine, because the test data is collected by the computer, and then through the calculation of the software program to get the final data that the user wants, and can be printed out through the report. Commonly used in scientific research units, testing institutions, new product development, etc.
Second, according to the control system can be divided into
1. Frequency conversion system tensile testing machine: adopts variable frequency motor control system, and the stretching and compression speed are controlled by frequency converter.
2. Servo system tensile testing machine: servo motor control system is adopted, and the stretching, compression speed and displacement control are more accurate. The servo motor system is a servo control system, which adopts intelligent feedback type calculation, and can be fixed speed test, cycle test, program test and so on.
3, other driving methods tensile testing machine: through the DC motor control, the driving method of the tensile testing machine has been gradually eliminated due to low cost performance.
Third, according to industry and functional characteristics can be divided into
1. Metal tensile testing machine: The metal material has large tensile strength and small elongation, and it needs to be equipped with a metal punctuation extensometer.
2. Rubber tensile testing machine: The elongation of rubber or elastomer is relatively large, and a large punctuation elongation device is required. At the same time, the fixture design should consider the characteristics suitable for rubber and cannot slip. O-ring fixtures, tire industry fixtures, etc. can be added.
3. Plastic tensile testing machine: The tensile strength of plastic is larger than that of rubber, the elongation is large and small, and the three-point bending test is often tested.
4, textile tensile testing machine: the textile industry needs to test fabric fabric stripping, puncture, tear, single yarn stretching and other tests, fixtures and software is special.
5, paper tensile testing machine: paper needs to test tensile strength, ring pressure strength, vertical pressure, flat pressure, side pressure, peel strength, etc., more fixtures.
6, leather tensile testing machine: leather needs to test tensile strength, tear strength, etc., the test project is relatively simple.
According to the test materials: metal material fixtures and non-metallic materials fixtures;
According to the test temperature: normal temperature fixture, high temperature fixture, low temperature fixture, high and low temperature fixture;
According to the purpose: stretching fixture, compression fixture, bending fixture, shearing fixture, peeling fixture, tearing fixture, sealing fixture, bending and bending fixture;
Seven, according to the degree of automation: manual fixtures, pneumatic fixtures, electric fixtures, hydraulic fixtures.
1. The force measurement of the tensile test machine is measured by the load cell, the amplifier and the data processing system. It is known from the data mechanics that under the premise of small deformation, the strain ε at a certain point of an elastic element is proportional to the force received by the elastic element, and also proportional to the elastic deformation. Taking the S-type tester sensor as an example, when the sensor is subjected to the pulling force P, since the strain gauge is attached to the outer surface of the elastic member, since the strain of the elastic member is proportional to the size of the external force P, the strain gauge is inserted into the measuring circuit. , the output voltage can be measured, and then the force is measured.
2. The measurement of the deformation is measured by the deformation measurement installation, which is used to measure the deformation of the sample during the course of the experiment. There are two chucks on the installation, which are connected with the photoelectric encoder mounted on the top of the measurement installation via a series of bio-signal structure. When the interval between the two chucks changes, the shaft of the photoelectric encoder is twisted and photoelectrically encoded. The device will have a pulse signal output. The processor then disposes of the signal to obtain the amount of deformation of the sample.
3. The measurement of the beam displacement is roughly the same as the deformation measurement. The displacement of the beam is obtained by measuring the number of output pulses of the photoelectric encoder.