Structural Design And Analysis Of Boom Tower Crane

Beginning from the 13th Five-Year Plan of Chinese state,Construction industry got unprecedented and new situation base on the state’s strong supporting.Under the national policy,construction machinery had new opportunities for development of construction industry.As an indispensable construction equipment for construction industry,luffing tower crane plays an important role in the construction field.The original project is based on the topic of "Automatic Control Technology and System Research for Lifting and Installation of Industrial Building Components",and research relevant technology which is suitable for hoisting and installing industrial assembly building components.The project focuses on model SCL140 luffing tower crane which is demanded by Shenxi Machinery Co.,Ltd.The rated lifting torque is 140t.m(Max torque is 21 6t.m).The main job content as follows:(1)Base on the classical and modern advanced design and refer to the relevant design specifications,the metal structure of the luffing tower crane will be calculated by allowable stress method and propose related design calculation methods.(2)Considering the structural eccentricity of boom triangular cross-section,modeling boom,simplifying the model,stress analysis and formula derivation,a calculation method for checking the stability of boom triangular cross-section is proposed.Widely used in the design of metal structures of the tower crane.(3)Select four working conditions,perform finite element modeling and analysis on the metal structure of the luffing tower crane,and check the strength and stiffness of the metal structure of the luffing tower crane,the stability satisfies the design requirements which is analyzed by ANSYS and AutoCAD,and verifies insight into the relevant calculation theory and structural design method what is proposed in this paper.(4)Lighter boom is made as optimization target,select the second elevation working condition,and OPT module of ANSYS is used to take the minimum equivalent mass of the total weight of the boom metal structure as the objective function.Constraining the strength,stiffness and stability of the upper and lower chords,the first-order method is used to optimize the metal structure of beam.The total volume of the boom metal structure is reduced from the original 0.824m3 to 0.758m3,and the weight is reduced from 6.468t to 5.951t,weight is reduced by 0.517t,and it is reduced by 7.99%approximately.Finally,the weight of the boom is reduced by optimization.(5)Perform modal analysis on the selected four working conditions and obtain the 8th order natural frequency and main vibration pattern of the whole machine under four working conditions and explain the vibration form of the metal structure of the luffing tower crane under various modes.The influence law of the elevation angle of the boom on the natural frequency will be given,which has guiding significance for the dynamic test of the product prototype.(6)Engineering drawing of the 2D and 3D for the relevant metal structures must be finished so that provide product basis for sample machine,and then sample luffing tower crane will be manufactured.