Designand Analysis Of A Triangle Boom Structure Of A Tower Crane

With the sustained and rapid development of the national economy,China's energy demand for electricity will continue to grow.At present,the domestic power industry adopts the policy of “big pressure and small pressure” for energy conservation and environmental protection requirements,and China's power construction has turned to vigorous development.Nuclear power and thermal power plants with higher parameters above 1000 MW.Nowadays,the capacity of power plants at home and abroad is continuously expanding,and the volume and weight of power station boilers and equipment are getting larger and larger.Traditional boom tower cranes at power stations are more likely to achieve large lifting capacity,but they are not easily realized and vary greatly.Slow speed and high power consumption.Large-scale flat-top tower cranes have many advantages such as rapid amplitude change,large operating range,low energy consumption,etc.,and are increasingly welcomed by customers.The development of domestically-made large-scale flat-top tower cranes is imminent,and it is also a general trend.The booms play a crucial role.The important role.The cranes of large-scale flat-top tower cranes are now relatively large and heavy and the research is not mature enough.The design of the boom will directly affect the lifting performance of the whole machine,and it will also have a big impact on the jacking system.This project is aimed at the development of the large-scale flat-head tower crane boom,the analysis and discussion of the structure of the boom structure,and the use of an inverted triangle-type boom.Firstly,the strength,stiffness and stability of the boom were analyzed by using the classical design method,and the initial calculation and design of the program were completed.Then,a detailed finite element statics analysis was performed on the eight main operating conditions of the boom,and the classical design method was well verified.The structural design safety of the boom was effectively ensured.Through the modal analysis of the flat-head tower crane,the first 8 natural vibration natural frequencies and corresponding vibration modes are extracted.Through the transient analysis,the deformation trend of the tower top joint under the dynamic stress of the structure and the dynamic load effect is obtained and analyzed comprehensively.The dynamic characteristics of the structure.Finally,a stress test method was used to test the boom structure,and the correctness and safety of the design were further verified.This subject has obtained the following results and conclusions after researching: The most dangerous working conditions of the main chords of the boom are the lifting load at the maximum amplitude,rotary brake,and wind in the plane of rotation;the most dangerous parts of the boom of the boom The working conditions are the corresponding amplitude rated load of lifting at the root of each section,rotary braking,and wind in the plane of rotation,which have guiding significance for similar designs.For cranes with high-strength materials,the rigidity of the boom is weak and the deformation is large,which increases the danger of hoisting.It is advisable to integrate the deformation of each working condition to set the upturn to counteract some of the vertical deformation.The natural frequencies of the first 4 natural vibrations are related to the vibration mode and the bending stiffness of the tower.The natural frequencies and modes of the 4th order natural vibration are related to the bending stiffness of the boom.Therefore,when designing a flat-head tower crane structure,it should not only pay attention to whether the strength and stability meet the requirements,but also control the stiffness as a key index.And we must stagger the frequency and the structure's natural vibration frequency excited by the external load to prevent resonance.