Research On The 3D Parametric Aided Design System Of Luffing Building Working Arm

The Building Maintenance Unit(BUM)is used as new type equipment for washing and maintaining high-rise building external wall.It has the characteristics of high efficiency,fast working speed,high safety,energy conservation and environmental protection.Current the BUM design mainly adopts the traditional design method.It has the disadvantages of long design period.With the rapid development of the information technology,the traditional design method is bound to be replaced by computer based design method.It urgently needs a sort of professional computer aided design(CAD)system,this is the reason of our team creating the 3D parametric CAD system for luffing BUM.The main research of the thesis includes:First,the paper deduces the relationship between the working length of the luffing BUM and the length of the arm and the number of arms.The designer can obtain the design result according to the developed program and only need to input the specified parameters in the design interface,including the number of arm,arm length,lap length,extension length,arm cross-sectional size and other information.Second,build the working arm parts library and database.Through the statistics of existing pitching drawings,standardized sections of the arm structure,the establishment of luffing BUM arm parts library.The database is used to store the dimensions of these parts under different conditions and lay the foundation for the subsequent parametric modeling.Finally,the development of three-dimensional parametric design system of luffing arm is completed.This part is the secondary development of Solidworks,the program calculated by the length of the arm and cross-sectional size and other parameters passed to Solidworks,the filter in the component library to meet the requirements of the model and copy the database to read the corresponding cross-sectional size of the value,The value assigned to the variable,the use of size-driven technology,access to the new size of the three-dimensional model and two-dimensional drawings.Compared with the traditional design method,the 3D parametric CAD system for luffing BUM can greatly improve the design efficiency,reduce the work load of designer,improve the design accuracy and have a certain development prospects.