The Design Of A Micro Fatigue Machine For High Frequency

Researchers found that the fatigue testing machines testing tensile and compressiveresistance simples are various, but ones with a large stroke, high frequency are few.Nowadays, fatigue testing machine is applied widely, but the traditional fatigue testingmachine cannot meet the requirement of the mechanical property tests about rubber, polymermaterial, composite material, biomedical material and equipment. Compared with traditionalfatigue testing machine, we design and manufacture a smaller micro-loading device withhigh-precision, high performance and high frequency, considering the dynamic mechanicalproperties of biological materials.This study aimed to develop a micro loading device to fill the lack of machine with largestroke, high frequency in the area of studying fatigue testing machine. In the research phase,we firstly proposed the voice coil linear motor as drive unit of fatigue testing machine, givingup the traditional method of using stepper motor or piezoelectric ceramic as drive unit. It canavoid the mechanical transmission link of stepper motor to select voice coil linear motor,achieving the advantages of zero transmission, zero hysteresis, high-precision, andhigh-frequency. Secondly, explored and designed the overall structural of fatigue testingmachine according to the voice coil linear motor chosen. In addition, a new type culturechamber which can provide a sterile environment close to the condition under physiologicalloads, applied in biomedicine, was designed. Finally, the natural frequency of the motor wascalculated using the finite element software to prevent resonance in the actual work, ensuringthe reliability of the structure of fatigue testing machine before produced. In the control, wechose the Imac400as a control system of the entire apparatus finally after comparing theCspace and Imac400control systems.The micro fatigue testing machine in this research can clamp the specimen with a size upto300mm, applying a loading frequency up to200Hz, carrying compressive or tensile testwith the maximum stroke of30mm. It implements the high-frequency test under the premiseof high loads and high dynamic strain. Another study characteristic is that the fatigue testingmachine can also be applied to biomedical research to test the fatigue life of biomedicalmaterials and devices, except the fatigue test of metal or non-metallic. Cell or tissue is alsocan be cultured in the condition under loading combining with the new type training roomdesigned independently.Combining the traditional mechanical design with biomechanics, this device not only canbe used as a fatigue testing machine, also can be used as a bioreactor. This study not onlyprovides a strong basis for the future development of cross disciplines of mechanical andbiological, but also provides a new way for research institutes, universities, companies and testing laboratories.