Design And Research On The Structure Of Prestressed Boom Tower Crane

This year,the rapid landing of the two hospitals of Vulcan Mountain and Lei Shen Mountain play a vital role in the epidemic situation in China,it not only embodies the cohesion and comprehensive national strength of our country,but also shows us the development of rapid assembly buildings.Few years ago,to raise the level of assembly in new buildings,our country had begun to vigorously promote the popularization and development of prefabricated buildings.However,in actual construction,the development of prefabricated buildings is impacted by the restriction of assembly building progress which is limited by the lack of lifting performance and poor lifting precision of tower crane.Although the prestressed boom tower crane came into being,it was not enough to meet all the requirements of rapid assembly.In this paper,the capability of prestressed tower crane of lifting capacity,controlling deformation,controlling cost and dealing with special working conditions is greatly improved based on the upgrade of the original prestressed tower crane structure on the premise of security.Consequently,the main contents of this paper is as follows:To begin with,a novel method and structure is proposed to improve the performance of the prestressed crane.It can not only reduce the displacement of the lifting point and increase the lifting capacity,but also make up the condition of prestressed lifting arm tower crane of the original structure can not cope with the sudden unloading.Furthermore,it provides a new idea for the optimization design of the prestressing boom tower crane.Secondly,the new theory of improving the prestressing boom tower crane is obtained by the analysis of the basic principle of three tower cranes to improve the original structure,recalculate and determine various parameters of new tower crane such as lifting torque curve,and analyze the the stress of the prestressed lifting arm tower of the improved structure.Finite element analysis of three tower cranes,the improved structure prestressing boom tower crane and the original structure prestressing tower crane and the TC6018 flat head tower crane,is tackled by parametric modeling.Moreover,the static analysis of three different tower crane models is made by the load in the different moment curves of the three towers considering two dangerous conditions and the the lifting capacity and displacement of three types of tower crane are compared and analyzed in the security condition.Finally,finite element analysis of the two structures before and after improvement under the special condition of sudden unloading such as wire rope fracture is tackled and the maximum stress of dangerous section is compared and then the ability of prestressed boom tower crane with two structures to cope with sudden unloading conditions is compared.Furthermore,the relationship between the position of the improved prestressing rod and the displacement deformation and the maximum stress at the lifting point is summarized through the force analysis and finite element calculation to optimize the position of the improved pull rod is optimized and the optimal result is obtained.To sum up,the improved prestressed boom tower crane can better adapt to the rapid assembly building.