The lower beam of banana screen is a circular tube beam. Here, the outer diameter of the circular tube beam is changed from 325mm to 351mm, and the wall thickness is l0mm. The Solidworks-simulation software was used to analyze the stress of the circular pipe beam before and after the improvement. The same boundary conditions were applied to impose fixed constraints on the flanges at both ends of the screen beam. Then, the same mass element was arranged on the upper surface of the Angle steel of the five lugs of the screen beam, and the mass was taken as m=178kg. The inertial acceleration = Aw2=54.04m/s2, in a direction of 52° horizontally, is applied to the whole screen beam. Meanwhile, its own gravitational acceleration g=9.81m/s2 is applied. The middle section and front section are selected here, and the stress of the two cross sections before and after the improvement is compared. It is found that the maximum stress of the middle section after the improvement is 34.6MPa, less than 37.7MPa before the improvement. The maximum stress of the improved frontal section is 25.7MPa, which is less than 27.3MPa before the improvement.
After the improvement, both the maximum stress and displacement of the banana screen beam have decreased to a certain extent. However, when the original square tube beam is replaced by the improved round tube beam, the overall stiffness and mode of banana screen may change to some extent. Therefore, modal analysis is carried out on the improved banana screen after the screen beam, in order to verify the overall effect of the improved banana screen.
Compared with before the improvement, the third order natural frequency and the fourth order natural frequency decreased slightly after the improvement. The second, third, fourth, fifth and sixth natural frequencies, which are close to the banana screen's operating frequency, are put into 4) through modal analysis. The operating frequency of ZKS3661 large banana screen is 15.83Hz, which is located between the third natural frequency of 13.90Hz and the fourth natural frequency of 18.49Hz, and far away from the natural frequency, so there will be no resonance phenomenon. Q) The stress and deformation of the lower beam of ZKS3661 large banana screen are improved to some extent by increasing the outside diameter of the circular tube beam. After modal analysis of the improved banana screen, it is found that the natural frequency and mode shape of the improved banana screen are basically unchanged, meeting the design requirements.
