Papers by Author: Hong Yun Wang

Abstract: The mechanical properties of a magneto rheological (MR) fluid in tension and shearing have been studied in the magnetic field which is generated by a coil carrying different magnitudes of DC electrical current. An experiment setup was designed and fabricated to perform this operation. The magnetic behavior of the equipment was analyzed using software of ANSYS/Multiphysics. The shear yield stress represents the effect of the interaction force along the shear direction (perpendicular to the direction of the magnetic field). The tensile yield stress of MR fluids represents the effect of the interaction force between the polarized particles along the direction of the applied magnetic field. The shearing tests showed that the shear yield stress is proportional to the external magnetic flux density with an exponent of 1.19. The tensile yield stress is about four times of shear yield stress.

Abstract: The mechanical properties of a magnetorheological (MR) fluid in shearing, compression and shearing after compression have been studied in the magnetic field which is generated by a coil carrying different magnitudes of DC electrical current on a self-constructed test system. The relations of compression stress versus compression strain, yield stress versus compression stress were studied under different magnetic fields. The compressing tests showed that the MR fluid is very stiff at small compressive strains lower than 0.13. The shear yield stress of MR fluids after compression was much stronger than that of uncompressed MR fluids under the same magnetic field. The enhanced shear yield stress of MR fluids can be utilized to design the MR clutch and brake for new structure and will make MR fluids technology attractive for many applications.

Abstract: The ability of magnetorheological(MR) fluids to resist compression in the direction of magnetic field was tested to investigate the quasi-static squeezing process of MR fluids. A experiment setup was designed and fabricated to test the compression characteristics. Under the different magnetic flux density, the curves of the MR fluids were studied for yield stress versus compression stress, compression stress versus compression strain. The compression resistance of MRF was then measured for the different magnetic flux density for comparison with the shear yield strength of the same magnetic field. The results showed that the compression resistance of the MRF was much stronger than its shear yield stress for the same magnetic field strength conditions. The compression resistance of MRF can be utilized to design new magnetorheological devices.

Abstract: In this paper, a system was introduced, which bases on Flame Cutter NC System and software platform of LabVIEW which the USA NI company developed. Composing of NC machine, partition of modules and assignments, functions confirming, data processing of machining and control, structure of software by the numbers and realization method of two CPUs. The system makes use of multitasking of LabVIEW to make the programmer realize easily the task, which is difficulty to acquire in in tradition programme. It is a kind of comparatively convenient and swift thinking to realize system interface and multitasking by the platform of LabVIEW.