Strength Finite Element Analysis And Optimum Design Of Sieve Box Of HFZS1640 Vibration Screen

Vibration screen is a kind of sieving machine, which has been developed quickly in recent twenty years. Vibration screen has been applied widely in many industries such as mining, metallurgy, petroleum, construction. The sieve box of vibration screen is easy to damage by the fatigue under the effect of alternate forces. According to vibration screen design specifications, sieve box dynamic stress must be less than 24.5Mpa in the working process of vibration screen. Therefore, it is significant to reduce stress level and slow down stress concentration of vibration screen for in order to improve its working reliability and extend the life-span.Finite element analysis and optimum design are the main contents of modern design methods. This paper took the HFZS1640 vibration screen as an object of study, and did profound analysis on the dynamic nature of the sieve box structure of vibration screen taking use of large-scale finite element analysis software ANSYS. Then on the basis of above analysis, an optimum to the sieve box can be realized. At the end, the result is satisfied.This paper completed the following works: on basis of summing up practical experiences and analyzing engineering drawings and vibration screen system comprehensively, establishing a reasonable finite element model of the sieve box structure of vibration screen through the ANSYS software and carrying on the detailed discussions on the modeling problems; analyzing the sieve box structure modal of vibration screen through the ANSYS software and obtaining the sieve box first 15 step natural frequencies and the corresponding main modal type; taking analysis of the harmonic response of sieve box structure through the ANSYS software and determining distribution rule of all the nodes displacement, dynamic stress of the sieve box. Then with regard to the sieve box itself design defects and the weak link, proposing the program of improvement, and dealing with the analysis computation, then proving validity; carrying on the size optimization to the sieve box of vibration screen through the ANSYS optimization module, by taking all boards thickness which composed the sieve box of vibration screen as the design variable, by taking structural strength request which satisfied the sieve box as the constraints, by taking the overall quality of the sieve box as the objective function.The results show that, the established finite element model of sieve box structure of vibration screen more better reflects better the actual structure of sieve box, and satisfied the requirements of the stress analysis; according to the modal analysis, the natural frequency and working frequency of the sieve box are not coincident, there would have no resonance; The harmonic response analysis indicates that the original structure of sieve box has design flaws, and there are more serious local stress concentration. After the structure improvement by slowing down the stress concentration, the stress level obviously reduced; through the optimum design, the overall quality of sieve box is decreased, the dynamic stress distribution is more evenly, and after the optimum, it will not affect the original sieving effect of vibration screen.This paper first time applies the optimum design to the sieve box of vibration screen and gets successful effects. The benefit of this research is that it provides a better way for designing and improving the original vibration screen structure. At the same time, it is also valuable to apply it into the finite element and optimum method in other similar problems.