Research On Stability Of Telescopic Combined Boom Of Crane With Flecible Guy Ropes

With the development of large constuction projects, such as Wind Power andNuclear Power, and demend of integral lifting operation, all terrain cranes withmaximizational telescopic booms are needed. Complicated crane jibs are used inmodern constuctions to content the demand of integral lifting operations. Thetelescopic boom with super lift system has a good lifting performance in heavylifting operation, but because of the complex structure, its stability analysis hasbeen a difficulty which restricts the development of large telescopic boom in ourcountry, and it’s especially for the stability analysis of the combined telescopicboom. So far, there is no research domestic can be directly applied to engineeringdesign. In this paper, the stability analysis of the combined telescopic boom andthe telescopic boom with super lift system were studied. And this article seeks todo a little useful contribution in this respect.Crane jib with two symmetric tie rods is studied and its calculation methodand formula are presented. Differential equation with non-directional forcescaused by the two symmetric tie rods is established in critical condition. Accordingto the boundary conditions and proper parameter processing, the out-of-planecharacteristic equation is obtained for the crane jib. The contribution of the anglebetween two symmetric tie rods to the out-of-plane stability of the crane jib is alsodiscussed. The results show that, the crane jib with two symmetric tie rods hashigher out-of-plane stability than that with one, and the increase of the anglebetween the two symmetric tie rods will lead to the significant increase of theout-of-plane stability of the crane jib.Crane jib with super lift system is studied and its calculation method andformula are presented. Both of the in-plane stability and the out-of-plane stabilityare discussed, especially for the out-of-plane stability problem. Differentialequation by considering the two non-directional forces caused by the twosymmetric tie rods and the effect of the lateral stiffness of the super lift strut tie isestablished in critical condition. According to the boundary conditions and properparameter processing, the out-of-plane characteristic equation is obtained for thecrane jib. The effects to the out-of-plane stability of the crane jib of the super liftsystem structure parameters are also studied, which could be the reference forstructure design.The out-of-plane stability of the telescopic combined boom is studied. Differential equations of the main jib with super lift system and the vice jib underthe draft of one tie rod are established respectively with both Bending deflectionand torsional deformation in critical condition. According to compatibilityconditions of deformation, the characteristic equation is obtained to calculate theout-of-plane stability of the telescopic combined boom.