Analysis Of The Influence Of Eccentric Structure On The Whole Stability Of All-Terrain Crane

With the development of more and more large and even super-large engineering projects in wind power,petrochemical,mining,nuclear power,construction and other fields,the market demand for the large-tonnage mobile cranes is constantly rising.At the same time,it also puts forward higher requirements on lifting performance,turning capacity and operation stability of the crane.The continuous breakthrough in material makes the crane develop towards lighter and thinner.However,as the working height keeps refreshing and the lifting weight keeps increasing,the possibility of instability due to excessive deformation of the telescopic boom system before the strength failure increases geometrically.In order to excavate the lifting capacity of the telescopic boom system more effectively,engineers creatively added the super-lift and eccentric structure and other auxiliary structures for it.At present,there are a lot of researches on the effect of the super-lift on the expansion of the telescopic boom system.However,there are few researches on the eccentric structure.This paper analyzes the current situation and shortcomings of the researches on the stability of the combined boom system of all-terrain cranes at home and abroad,and elaborates the eigenvalue buckling theory and nonlinear buckling theory in detail.Eigenvalue buckling analysis,which is a non-conservative analysis method,is based on the theory of small deformation,and the critical load obtained is generally higher than the actual value.However,it is a good choice for studying regularity problems because of its fast solving speed.Nonlinear buckling analysis is based on the theory of large deformation.The telescopic boom system of all-terrain crane has a large deformation in the large range working condition,Therefore,geometric nonlinear buckling analysis is required to obtain conservative critical buckling load.The main research contents of this paper are as follows:?1?ANSYS was used to operate the eigenvalue buckling analysis and the geometric nonlinear buckling analysis of the 500T all-terrain crane with the fixed jib and the tower jib,and then to compare the buckling load changes of the boom system before and after the eccentric structure was installed.The results show that the eccentric structure can significantly improve the overall stability of the combined boom.?2?The influence of geometric dimension and installation Angle of eccentric structures on the stability of the combined boom system of all-terrain crane is analyzed.The relationship among the strut length,the strut opening Angle and the strut amplitude Angle is analyzed.The influence trend of the three main parameters of the eccentric structure,₀?₁?₂,on the overall stability of the combined boom system is approximately the same,and the critical load increases first and then decreases with the increase of the value of₀?₁?₂.?3?when the eccentric structure and the super-lift device cooperate with each other,based on the stability of the combined boom system,the relationship between them on the geometric dimensions and installation Angle is analyzed.The research shows that the optimal value of the eccentric structure strut is 100°,that is,the eccentric structure strut is up relative to the telescopic main arm,and the optimal value of the super strut is 90°,that is,the super strut is vertically arranged with the telescopic main arm.