As a testing equipment widely used in various industries, the tensile machine is used to test and analyze the mechanical properties of various metals, nonmetals and composite materials. The traction machine uses a micro DC servo motor for the power source;
The single-chip microcomputer displays the test data and test status in real time, and the control of the test process is carried out by the automatic control of the Realized single-chip microcomputer, which can automatically calculate the experimental data value, fractional value and other data.
Tensile testing machine measurement principle
1. The measurement of the force value of the tensile testing machine is completed by the load cell, the amplifier and the data processing system measurement.
It is known from data mechanics that, assuming a small deformation, the strain ε at a given point of an elastic element is proportional to the forceon the elastic element and is also proportional to the elastic deformation.
Taking the S-type testing machine sensor as an example, the sensor is subjected to the action of the tensile force P because the elastic member is bonded with a strain gauge, because the strain The magnitude of the elastic member is proportional to Magnitude of the external force P. So connect the strain gauge to the measuring circuit, you can measure its output voltage, and then measure the magnitude of the force.
2. The deformation measurement is done with the deformation gauge, 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 gauge by a series of memory mechanisms. When the distance between the two chucks changes, rotate the shaft of the photoelectric encoder, and the photoelelectric encoder outputs a pulse signal.
The signal is then processed by the processor and the deformation of the sample can be determined.
3. The principle of beam displacement measurement is roughly the same as that of strain measurement. The displacement of the beam is determined by measuring the number of output pulses from the photoelectric encoder.
Tensile testing machines can be classified as follows
1. According to the degree of automation, they can be divided into
1. Pointer Tensile Testing Machine:
This traditional tensile testing machine has been basically replaced by the digital tensile testing machine due to its low testing accuracy and low cost performance.
But in the small force range, it is our common strain gauge, widely used by factories for simple force testing of small products. Due to its low price, it still enjoys great onesr popularity .
2. The digital display tensile testing machine is also called microcomputer tensile testing machine:
The test data is displayed directly on the LCD screen Test items Relatively fixed, is often used in factory quality control.
3. Computer system tensile testing machine:
It is a universal tensile testing machine. Through the calculation and processing of the software program, it can obtain the end data the user wants and printed out in the form of a report.
It is widely used in scientific research units, testing institutes, new product development, etc.
2. According to the control system, it can be divided into
1. Frequency conversion system tensile testing machine: It uses a frequency conversion motor control system, and the tensile and compressive speeds run through the frequency converter control.
2. Servo system tensile testing machine: The servo motor control system is adopted to more precisely control the speed and displacement of tension and compression. The servo motor system is a servo control system that applies intelligent feedback calculation and can perform constant speed test, cycle test, programming test, etc.
3. Tensile testing machines with other driving methods: The DC motor controlled tensile testing machines with this driving method have been gradually phased out due to their low cost performance.
3. According to the industry and functional characteristics, it can be divided into
1. Metal Tensile Testing Machine: Metal materials have high tensile strength and low elongation. A metal puncture strain gauge is required.
2. Rubber Tensile Testing Machine: The strain rate of the rubber or elastic body is relatively large, and it needs to be tested with a large puncture strainerbe equipped. At the same time, the design fastening must take into account the properties of rubber and cannot slip. O-ring jigs, tire assembly jigs, etc. can be added.
3. Plastic Tensile Testing Machine: The tensile strength of plastic is higher than that of rubber, and the elongation rate varies, and three-point bending test is often tested.
4. Textile Tensile Testing Machine: The textile industry needs to test the shedding, puncture, tearing, single yarn tension and other tests of fabrics, and the fixtures and software are special.
5. Paper Tensile Testing Machine: Paper needs to be tested for tensile strength, ring compression strength, vertical pressure, flat pressure, side pressure, peel strength, etc., and there are many devices.
6. Leather Tensile Testing Machine: Leather needs to be tested for tensile strength, tear strength, etc., and the test items are relatively simpleH.
Four, according to the test material: metal material bracket and non-metal material bracket;
Five, according to the test temperature: normal temperature device, high temperature device, low temperature device, high - and low-temperature device;
Six, according to purpose: traction device, compression device, bending device, shearing device, peeling device, tearing device, sealing device, anti-bending and anti-bending devices;
Seven, depending on the degree of automation: manual devices, pneumatic devices, electric devices, hydraulic devices;