Dynamic characteristics of the telescopic boom considering the section deformation

XIE Yao1, ZHANG Lei1, TANG Ya-ming1, DING Gen-hong2
(1.College of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022, China;
2.College of Science, Hohai University, Nanjing 210098, China)

Abstract: Aiming at the problems of cumbersome dynamic modeling of telescopic booms, complicated solutions and low accuracy, by introducing high-order characteristic deformations used to represent warpage and distortion of section, a modeling and solution method for telescopic boom dynamics considering cross-sectional deformations was proposed. First, the modeling and solution of the boom section model were completed according to the Hamilton principle and the finite element method. Then, the crosssectional displacement at the arm joint was analyzed. Under the condition that the difference between the displacement fields of the two booms at the junction was minimum, the displacement field conversion matrix of the boom was established, and the dynamic model of the telescopic boom was constructed. Finally, the natural frequency of the boom calculated by the model was compared with the analysis results of ANSYS, and the numerical calculation of the boom with different geometric parameters and different boundary conditions were performed. The results indicate that the model calculation results are in good agreement with the ANSYS results, the error is within 1.2%. When the modal order is greater than 2, the influence of high-order feature deformation on the modal of the boom cannot be ignored, otherwise the error can be up to 10%.

Key words: higher-order characteristic deformation; thin wall structure; telescopic boom; dynamics characteristics; finite element analysis