Optimization Design Of QTZ100 Crane Based On Multi Character Analysis

Based on the improved design of QTZ100 tower crane of Shandong Dahan Science and Technology Co.,LTD.,this paper takes QTZ100 tower crane as the research object and makes cluster analysis on keywords of crane direction through Cite Space to get the latest research hotspot.The structure of QTZ100 tower crane is studied statically and dynamically by using assembly modeling technology and finite element analysis technology in ANSYS software,and the reliability of finite element technology is verified by model test.Through the static and dynamic analysis of the tower crane,it is found that the material redundancy in the current tower crane design is serious.The size of the boom of the QTZ100 tower crane is optimized,and the topology of the turntable is optimized.The research results of this paper can provide reference for the design and improvement of the same type tower crane structure.The main research work of this paper is as follows.(1)Establish the complete finite element model of QTZ100 tower crane.Firstly,the tower body and boom foundation model were constructed based on the point cloud function of Design Modeler,and the balance boom foundation model was constructed based on the spot welding function.Secondly,Beam188 element is used to construct the analysis model of the crane boom and tower body,and the analysis model of the balance arm and turntable is constructed by the fusion of beam element and shell element.Finally,based on the above analysis model,the complete analysis model of tower crane is constructed by mapping the assembly relation and contact relation.The construction of the analysis model lays a foundation for the subsequent static and dynamic analysis and optimization.(2)Statics analysis of tower crane.First of all,based on the analysis of the effect of wind load and gravity load,based on the sudden lifting state of the boom when lifting heavy objects at the maximum lifting range and maximum lifting weight,two typical working conditions of the tower crane are summarized and analyzed.Secondly,based on different working conditions,the static analysis of the whole machine analysis model is carried out.Finally,based on the analysis results,the stress concentration area of the tower crane is determined by the stress nephogram.The determination of the stress concentration area plays a guiding role in the subsequent optimization.(3)Dynamic analysis of tower crane.Firstly,based on buckling analysis,the minimum buckling factor of the tower crane located at the maximum lifting amplitude is calculated.On this basis,the critical buckling load of the boom is calculated according to the lifting mass.Secondly,the buckling mode is used to determine the buckling structure of the boom,and the natural frequency of the buckling structure and its corresponding frequency mode are analyzed.Finally,the peak displacement response is determined based on the response spectrum analysis,and the stress response of the ground motion load and the static load under the combined condition is analyzed.(4)Finite element verification based on model test method.Firstly,the constrained natural frequency of the upper turntable is analyzed based on ANSYS software.Secondly,a solid model with a similarity ratio of 1:10 and ABS material was established through the similarity theory,and 3D printing was carried out.Finally,the constrained modal test of the solid model is carried out by the force hammer excitation method.In the test process,considering the influence of many factors,such as welding process,sensor quality and insufficient binding force,there is a certain error between the test frequency and the simulation frequency,but the overall results are reliable.Since the essential difference between modal analysis and statics analysis lies in the different excitation modes,the verification of modal test means that statics is also consistent.It lays a foundation for optimizing the boom and upper turntable by finite element method.(5)With structural stress and buckling factor as constraints,lightweight design of the structure is carried out.Firstly,based on the experimental design of Latin Hypercube,the response surface method is used to optimize the size of tower crane boom.Secondly,the topological optimization of the upper turntable is carried out with the stiffness as the optimization objective and the mass as the constraint condition.Finally,the optimization is verified by statics analysis under the same working condition.