Component Structural Improvement And Structural Optimization Of The Rotary Drilling Rig

The rotary drilling rig is a kind of foundation construction machinery which is designed to drill holes of different diameters and depth. Compared to human piling, rotary drilling is characterized with high efficiency and environmental friendliness. After years of development, the rotary drilling rig on market has already achieved product serialization of power, torque and drilling radius. For the reasons above, the rotary drilling rig is becoming increasingly widely applied in construction and engineering field.The finite element theory as a design method has been widely spread in machinery designing and manufacturing with the calculation performance development of software and hardware. Using FE method we can carry out different kinds of perfor mance simulation on the product. High quality FE model is the basis of an accurate simulation. It is of significantly importance for the accuracy of analysis results to establish proper model of different research object and apply boundary conditions as it real y is.In this paper we put the rotary drilling rig as research object, established the parametric FE model of the whole machine using APDL in ANSYS. The key dimensions of members and attitude of the whole machine can be adjusted. The correctness of the model is verified through the field stress test with the absolute error of stress is below 15 MPa between actual stress value and simulated stress value. We carried out the transient respond analysis of the rig in the pipe- lifting rope-break scenario which may happen in construction, and the historical equivalent stress distribution of mast II has been obtained after the rope breaks. According to the analysis results the structure of dangerous area in mast II is modified. The equivalent stress of the area descended from 368 MPa to 252 MPa. The original design of the triangular frame has been modified based on the sub- model method and topology optimization. The modified version of the triangular frame reduces its weight by 12.9%, and the equivalent stress distribution is more averaged.