Tower Crane Twin-lift Horizontal Jib Structure Optimization

Tower crane is a significant construction equipment in construction projects,which is applied widely in industrial and civil building, energy infrastructure,water conservancy construction, shipbuilding industry and so on. With start ofChinese energy infrastructure such as wind power project, nuclear power projectand photovoltaic power project in succession, tower crane is developing in thedirection of large scale, heavy load, high reliability and high efficiency in recentyears, which results in stricter requirement for tower crane structure design thanbefore. Tower crane structure is composed of tower body, tower head, cargoboom, balance boom, counter weight, slewing bearing, underbed and so on.Cargo boom as important load-carrying component will be designed at first,which design result could improve or limit design quality of other structuralparts in downstream link, so cargo boom optimization could not only bring inobvious economic benefit, but also be helpful to enhance design level ofcomplete machine.In this thesis, tower crane boom will be studied and the main content is asfollows:Firstly, reasonable mechanical model is established according to workingcondition and load feature. Parametric boom model is created through ANSYSclassical module and ANSYS Workbench module by virtue of commissionedcrane jib parameters. The comparison of two modeling methods could guideenterprise technicians to create models properly.Secondly, finite element method (FEM) analysis of crane jib is carried outand objective parameters are extracted from post-processing. Safe indexes ofboom include: strength, rigidity, stability. Secondary development of crane jibanalysis with APDL is utilized since stability parameters can’t be extracteddirectly from ANSYS. That is, algorithm is written which conforms to format of APDL and absorbs design theory of boom stability, and boom analysis module iscreated.Thirdly, single objective optimization of crane jib structure with fixedcontinuous/discrete variables is realized through combination of ANSYS andIsight. Crane jib weight is regarded as objective function. shape steeldimensions、strength、rigidity、stability parameters are limited, and optimalshape steel dimensions are determined at the end.Finally, multi-objective optimization of crane jib structure with fixedcontinuous/discrete variables is realized through combination of ANSYS andIsight. Crane jib weight and crane jib vibration parameter are both regarded asobjection functions. Crane jib weight is regarded as objective function. shapesteel dimensions、strength、rigidity、stability parameters are limited, and optimalshape steel dimensions are determined at the end.