Shenzhen Enpuda Industrial System Co., Ltd. is a technology-based enterprise integrating scientific research, product development and production, program implementation, and technical consultation in materials and structural mechanics testing. The fatigue testing machine is characterized by high load, high frequency and low consumption, thereby shortening the test time and reducing the test cost.

The fatigue testing machine is used to determine the fatigue characteristics, fatigue life, and fatigue life of metals, alloy materials and their components (such as operating joints, fixed parts, spiral moving parts, etc.) at room temperature under tension, compression or alternating tension and compression loads. Pre-crack and crack growth test. After being equipped with corresponding test fixtures, the high-frequency fatigue testing machine can perform three-point bending test, four-point bending test, thin plate tensile test, thick plate tensile test, reinforced steel bar tensile test, chain tensile test under sinusoidal load Test, fixed connection test, connecting rod test, torsion fatigue test, combined bending and torsion fatigue test, interactive bending fatigue test, CT test, CCT test, gear fatigue test, etc.

Test method: Fatigue test refers to the determination of σ-1 of metal materials through metal material experiments, drawing the S-N curve of the material, and then observing the fatigue failure phenomenon and fracture characteristics, and then learning the method of determining the fatigue limit of metal materials under symmetrical cycles. Testing equipment generally includes fatigue testing machine and vernier caliper.

Under the action of a sufficiently large alternating stress, the sudden change in the shape of the metal component or the surface scratches or internal defects may cause micro-cracks due to the large stress concentration. Scattered micro-cracks will form macro-cracks through assembly and communication. The macroscopic cracks that have formed gradually expand slowly, and the cross-section of the component gradually weakens. When a certain limit is reached, the component will suddenly break. The above-mentioned failure phenomenon of metal caused by alternating stress is called metal fatigue. Materials with good plastic properties under static load, when subjected to alternating stress, often break suddenly when the stress is lower than the yield limit and there is no obvious plastic deformation. The fatigue fracture is clearly divided into two areas: the smoother crack propagation area and the rougher fracture area. After the crack is formed, the alternating stress causes the two sides of the crack to open and close from time to time, squeezing each other and repeatedly grinding, and the smooth zone is formed in this way. The discontinuity of the load and the change of the size leave multiple crack front lines in the smooth area. As for the rough fracture zone, it was formed by a sudden fracture at the end. Statistics show that about 70% of the failures of mechanical parts are caused by fatigue, and most of the accidents caused are catastrophic. Therefore, it is of practical significance to study the fatigue resistance of metal materials through experiments.

Classification: Fatigue testing machines can be divided into low frequency fatigue testing machines, intermediate frequency fatigue testing machines, high frequency fatigue testing machines, and ultra high frequency fatigue testing machines according to the testing frequency. The frequency lower than 30Hz is called low frequency fatigue testing machine, the frequency of 30-100Hz is called intermediate frequency fatigue testing machine, the frequency of 100-300Hz is called high frequency fatigue testing machine, and the frequency above 300Hz is called UHF fatigue testing machine. Mechanical and hydraulic types are generally low frequency, motor drives are generally medium frequency and low frequency, electromagnetic resonance type is high frequency, pneumatic and acoustic type are ultra high frequency.

Composite materials can not be fatigue tested with electromagnetic high-frequency fatigue testing machine, because the electromagnetic type is driven by the principle of electromagnetic resonance, which is related to the rigidity of the sample, so composite materials can only be driven by a motor for fatigue testing.

Working principle: The high-frequency fatigue testing machine works according to the principle of electromagnetic resonance and relies on the vibration of the electromagnet to apply the load. It is the first choice for the larger load of 20KN-300KN and the frequency of 80-250Hz for short test time. The frequency needs to be adjusted, and the frequency is fixed in several gears. According to the feedback of the user, the frequency adjustment operation is more troublesome.

The low-frequency fatigue testing machine works according to the principle of electro-hydraulic servo, relying on the reciprocating motion of the hydraulic cylinder to apply load, the first choice for large load 5KN-1000KN and low frequency 0-10Hz, generally recommended to use around 10Hz, higher frequency is for hydraulic servo The friction damage of valves, sealing rings, etc. is too large, and the subsequent maintenance costs are too high, and higher frequencies are not recommended. If the maintenance cost is not considered, it is also possible to use 20Hz and 30Hz, but the life of the hydraulic fatigue testing machine will be greatly affected.

development trend:

More humane: The future development of fatigue testing machines will be more humane. From equipment conception to design to production to sales and to our users, every step is based on humanity as the first consideration. It can be better and more convenient for us to use, for example, ergonomic equipment design and so on.

More intelligent: The fatigue testing machine will be more intelligent in the future development. For example, it can intelligently turn on and intelligently shut down, and intelligently automatically grab samples, transmit and compare data in real time during the test, and then intelligently remove the sample to save the test data after the test is completed. And then grab another sample to be tested.

More functional: There are many types of testing machines, but one type of testing machine can only do one type of test. Although there is a universal testing machine on the market, it is really omnipotent. I don’t think it is necessary, so in the future In the development of the fatigue testing machine, the functions of the testing machine will also be integrated. One testing machine can do several types of tests and truly realize the "universal". The development of science and technology can promote the development of testing machines, and fatigue testing machines will also be more humanized, intelligent and functional.

The company has been adhering to the business philosophy of "technological innovation and sincere service to users", and has won customers with excellent quality and service. The company has a capable R&D team and a group of experienced technical production backbones who have worked in the testing equipment industry for more than ten years, and has now developed more than a dozen series of more than 200 models of products. The testing machine has been widely used in universities, scientific research, quality inspection and enterprise users. It is the performance analysis and quality of metal, non-metal, composite materials and structural parts and parts in the fields of national defense and military industry, aerospace, rail transit, shipbuilding industry, civil engineering, building materials, biomedicine, metallurgical manufacturing, cables and wires, and household appliances. A reliable choice for control.