Mechanical Characteristics Analysis Of Rigid And Flexible Tie-in Of Hoist

Hoist has become indispensable to construction equipment in the construction personnel and material transport, since the birth of the first homebred hoist in1973, after30years of continuous development, Hoist is in the structure form, function, usage, safety devices and other aspects of great change and development, Therefore, The key factor of industry development is in the design of structure reliable, safe hoist. The whole system has always been accompanied by vibration phenomenon, when hoist in the process of operation. As the gear and rack meshing, dynamic excitation will be generated. The movable eccentric effect will be generated by cage on the mast section, as well as the cage start or stop when accompanied by dynamic impact or step excitation. Because of the vibration will cause structural resonance or fatigue, Thus the structure will be destroyed, In order to avoid the damage of structure, Therefore, understanding the vibration characteristics of the structure itself, such as natural frequency and vibration mode, is of great significance,unnecessary loss caused by resonance will be avoided in use.This paper on the ultra high type of rigid tie-in and flexible tie-in schemes of the static, dynamic mechanical properties of hoist, as well as the vibration and strength are analyzed, the specific following work are done:first, In order to find the dangerous section position of the mast section of structure system under different working conditions, a three-dimensional model and finite element model of rigid tie-in of hoist are established and the mast section is the height of150meters high, static characteristics on finite element model are analyzed, the maximum stress and deformation point under dangerous working conditions are obtained, the weak links of the structural system are determined. Then, using ADAMS software, the ultra high type rigid tie-in of hoist of the multi body dynamics model are established, as well as the rigid-flexible coupling dynamics model, Based on the analysis of its dynamic characteristics, the first six order natural frequency of structural system are obtained. And the mast section at the top of cantilever end changeable vibration mode with time is also obtained. The vibration condition of hoist is analyzed. Finally, through the rigid-flexible coupling dynamic model analysis, the dangerous section position in the operation process of cage of force versus time curve are obtained, and provide the basis for structural strength and the calculation of the mast section root local stress and total stress. The flexible tie-in of hoist did the same work, the static, dynamic characteristics are analyzed, and also the vibration and strength analysis, similarly, the maximum stress position and maximum deformation of a flexible tie-in scheme of hoist are identified, the dangerous section changes with time of stress and deformation are analyzed, and the vibration frequency and the resonance are studied. Through the ANSYS static, modal analysis and ADAMS dynamic analysis, In accordance with the actual conditions, on the basis of the model is verified, the following conclusions are drawn:First, through the ANSYS static analysis, the dangerous section of structural system taking place have been determined, The maximum stress occurs in the base section of the mast section, the maximum deformation occurred in the top position of the free end, Second, through modal analysis and dynamic analysis of rigid flexible coupling system, the first six natural frequencies of the structural system are not equal to the frequency of exciting force exerted in the structural system, So the resonance phenomenon does not occur, Third, using ADAMS software simulation, dangerous section force versus time curve have been obtained, local stress and total stress of the mast section root meet the strength requirements, Thus these provide experimental guidance for practical engineering, Fourth, through the ADAMS simulation process, When the cage move up and down on the mast section, the cantilever of mast section top mode changeable with time can be obtained, the deformation of danger end are more realistic responded by the dynamic vibration model, In order to ensure the stability and safety of the structural system,the tie-in stiffness should be increased.