Application of Similarity Theory for Dynamic Characteristics Prediction of Crane Flexible Truss Boom

Xuyang Cao,Zhiwei Wang,Wenjun Wang,Xiang Dong

doi:10.1155/2020/4273810

Abstract

The aim of this study is to explore the similarity relations of dynamic characteristics of crane flexible truss boom. Combining perturbation theory with vibration analysis, a calculation method of the flexible boom natural frequency undergoing large overall rotary motion was proposed. According to the similarity theory, in terms of the geometrically similar truss boom, the similarity relations of their natural frequency and other parameters were derived. Taking the slenderness ratio of the actual product as the reference standard, two groups of scale-down crane truss boom experiments were designed. The results showed that, in aspect of the boom section size and the boom length, by using the similarity relations of the flexible boom, the dynamic characteristics can be predicted well.

Highlights

In order to meet the construction requirements of modern large-scale engineering projects, hoisting machinery is developing in the direction of towering and softening [1, 2]
The flexible deformation of the boom structure undergoing large overall motion is a difficult problem in boom design; relevant design specifications do not consider in depth the influence of the nonlinear dynamic characteristics of the boom on the operation accuracy and reliability [3] and lack effective theoretical guidance for serial design of boom
Similarity theory has the advantages of generality and rigorous digital derivation process, apply the similarity theory in the field of crane boom, derive similarity relations guiding boom design will become an efficiency design method

Summary

Introduction

In order to meet the construction requirements of modern large-scale engineering projects, hoisting machinery is developing in the direction of towering and softening [1, 2]. Wang et al [13, 14] derived the complex shells dynamic similarity relations of underwater vibrations and the influence of the boundary effect on the similarity relation based on the equational analysis method and can be used to predict the vibration response of complex large-scale underwater structures accurately. In the respect of crane operation and design, Dai et al [16] applied the similarity theory to simulate the welding process of the swing arm of a large hydraulic excavator and derived the similarity rule of single-layer welding based on temperature field in certain conditions. According to the numerical calculation results of the equation, the similarity relation of the dynamic parameters of the truss boom can be obtained based on the equational analysis method of similarity principle. According to the numerical calculation results of the equation, the similarity relation of the dynamic parameters of the truss boom can be obtained based on the equational analysis method of similarity principle. e correctness of the similarity relation is verified by numerical calculation and similar model experiments

Force Analysis of Crane Boom System

Natural Frequency of Flexible Boom

Derivation of Similarity Relations of Flexible Truss Boom

Similarity Model Experiment and Result Analysis of Crane Flexible Truss Boom