|
Reliability of perforated vibrosurfaces, which are involved in the sifting of loose media, is one of the main parameters of efficiency of their operation in many technological processes. A proven promising way to intensify the separation of loose media is the use of perforated vibrosurfaces with holes of complex geometric shape. Such vibrosurfaces with many holes provide an increase in the productivity and quality of loose media separation process, but do not have developed methods for a comprehensive assessment of their reliability. Existing methods for studying vibrosurfaces with standard single holes and the corresponding results cannot be used to study the reliability of vibration surfaces with holes of complex geometric shape. Determining the natural oscillations of vibrating surface with holes of complex geometry is one of the main initial steps in the study of reliability. The proposed method is based on the experimental modal identification of the parameters of natural oscillations, the parallel creation of a numerical model using the finite element method, the comparison of the results. Three vibrosurfaces were investigated: solid without holes; perforated with standard round holes; perforated with holes in the form of a five-petal epicycloid. As a result of experiments, the divergence of natural vibrations of perforated surfaces depending on the side of the punch and matrix during their technological production by pressing was established. A methodology is proposed that will allow for such discrepancies and improve the accuracy of experimental studies. The result of the research was a refined adequate numerical model that takes into account the presence of holes of complex geometric shape on the vibration surface. A methodology has been developed and analytical expressions with perforation coefficients have been obtained, which allow obtaining values of natural oscillations of vibration surfaces depending on the properties of metal, boundary conditions and structural and kinematic parameters. The obtained studies will optimize the structural and kinematic parameters of perforated vibration surfaces with holes of complex geometry according to reliability criteria. The authors acknowledge the financial support of the National Science Centre in Krakow to the research project funded in the „POLONEZ BIS 2" call No. 2022/45/P/ST8/02312 entitled Numerical-experimental analysis of a sieve holes' shape and arrangement effect on the degree. POLONEZ BIS is operated by the Centre on the basis of the Grant Agreeme nt No. 945339 concluded with the European Research Executive Agency.
|
