Finite Element Analysis And Optimal Design For Pitch Structures Of Bucket Wheel Stacker-Reclaimer

As a kind of continuous loading and unloading machinery equipment, bucket wheelstacker-reclaimer plays a great role in coal yard, bulk transportation ports, steel mills ore yardand other places which due to its high efficiency. Pitch structure is an important part of theequipment, the features of the equipment is high self-weight, long overhanging, complicatedstructure and force situation, its reliability and security cannot be ignored, therefore, thestiffness,strength and vibration characteristic of the pitch structure must be considered inorder to ensure safe operation of the equipment.Using three-dimensional modeling software UG NX6.0to establish geometric model ofpitch structure according to relevant technical data, then simplify the model appropriately,after that importing the model into HyperMesh software and cleaning up ithe geometry, usingits former processing functions set proper element type for different structure, then establishthe finite element model of the structure, and import it into ANSYS through the interface file.Exploit the solve function of ANSYS, complete static finite element analysis of three typicalworking conditions: gravity load, regular work and overload work. Each working conditioncontains three kinds of working state which are boom is horizontal, pitch up and under to thelimit position. Through the displacement analysis results determine the structural deflection ofseveral key positions, and complete the checking of rigidity; Through the equivalent stressanalysis results complete the checking of strength，and analyse the overturning stability of thestructure.Paper also finished modal analysis which structure is undering the condition of no-loadand full load, get the first eight order natural frequency and vibration mode of the structure.Bycomparing the external excitation frequency and inherent frequency, to test whether structureresonates, and on the basis of modal analysis, using the modal superposition method forharmonic response analysis, further get amplitude frequency response of the structure underthe action of excitation of the head, and get the safety bucket wheel speed range by analysingresults. These conclusions provide a basis for the comprehending of structure vibrationcharacteristics for the designers.Otherwise, the paper also make optimization and improvement at the forearm rack ofstructure, with the size which make largest influence on forearm rack mass as design variables. In the meet of certain stiffness and strength, with the minimum total mass as the objectivefunction, using multi-objective driven optimization technology of ANSYS Workbench tomake optimization and improvement in forearm rack, therefore, realizing the light weight instructure.