Open-air Rotary Drilling Rig Underframe’s Finite Element Analysis And Design Improvement

Underframe plays a supporting and fixed role on the drilling rig. Its’ reliability directly affects the performance of the drilling rig. Whether its response which is under static and dynamic loads are within a reasonable range is very important to its reliability. So implementing static and dynamic simulation analysis and understanding the response of the underframe are meaningful to the underframe for its design and improvement.Topic of this study stems from the Yunnan Bureau of Mines Xiaolongtan. The drilling rig is crawler travel-type. According to the available resources, I decided to use the DFH-75tractor’s underframe as my research object. Analysing whether its ability can meet the use of the drilling rig. And implementing some related design and improvements for the underframe on the basis of the analysis.I used the finite element analysis method in this thesis and carried out the simulation analysis for the underframe. The summary research is:Creating a three-dimensional solid modeling in UG for the underframe which has modified. Then directly importing it in ANSYS Workbench by using the two-way link function of UG and ANSYS Workbench. In the pre-processing stage of finite element analysis, I setted the definition of material properties, definition of contacts, the definition of meshing operations and finally I completed the establishment of the finite element model of the underframe. Then I made a static simulation for the underframe in four force-dangerous working conditions (drilling working conditions, upgrading working conditions, climbing starting working conditions, flipping conditions). The underframe has a greate concentration of stress under the front support plate in the upgrading working conditions. It surpasses the material’s yield limit. So, I made some improvements for this structure, and then the concentration of stress is missing. Its strength meets the demand. I made an analysis for the underframe’s deformation which is in Y direction. Then I drew an conclusion that the underframe’s bending stiffness is not enough slightly. By making a freedom modal analysis for the underframe, I got a result that the first few natural frequencies of the underframe is larger than the random vibration frequency of road and the frequency of the engine. Finally, I made some improvements for the underframe basing on the above analysis. Through the simulation analysis for the improved underframe, I got a result that the underframe’s improvements meet the design requirements and achieve the purpose of improving.