Papers by Author: Wen Tie Niu

Abstract: In order to improve dynamic and static performance of the precision horizontal machining center, the method of multi-objective optimization based on the response surface model was applied for optimizing design of the bed structure. The design variables were the layout parameters of the rib plates. Sample points were obtained by the Box-Behnken design experiment, and responses of sample points were analyzed by SAMCEF. The maximum deformation of guide rails and the low-order natural frequency were extracted to fit the response surface model by least square method. The layout parameters of the rib plates were optimized through the application of multi-objective genetic algorithms. Then, relationship between the lightening holes and the performance were analyzed to determine the suitable diameter. The results verify the validity of the optimization method, and the paper provides methodological guidance for optimization of machine tool structural parts.

Abstract: In oilfield exploitation, automatically directional steering can only be achieved with rotary steerable system (RSS). The designed well trajectories have become more complicated e.g. horizontal wells, extended reach drilling wells and 3D multi-target wells. To drill these complicated wells, new drilling tools are urgently needed. This paper proposed a new steering mechanism for point-the-bit RSS. The new steering mechanism uses a set of universal joints to avoid the high alternative strain on drilling mandrel, and it uses a specific eccentric planetary gear train to offset the drilling mandrel to achieve directional steering. Design procedure, Solid modeling, Force analysis and dynamic simulation have been discussed for further dynamic analysis towards the confirmation of the steering performance.

Abstract: An online approach was presented to test and evaluate the dynamic performance of feed drive system. At first, the position ramp trajectory, speed ramp trajectory and reciprocating trajectory were run separately and the response data was obtained from Numerical Control System. Then, a set of criterions were defined to evaluate the dynamic performance of five axes respectively. Finally, the integrated performance of the feed drive system was evaluated through analytic hierarchy process. On the basis of above theory, a rapid test and evaluation software was developed and this paper presented the results achieved in practice with this software. The research could provide a foundation for understanding variation rule of dynamic performance of feed drive system and improving its dynamic performance

Abstract: On the basis of test and evaluation theory, the software was developed to evaluate the online dynamic performance of CNC machine tool. After the standard test program was run, the response data was obtained through data collection system. Then the dynamic performance of CNC machine tool was fast appraised. Finally, all of test data and evaluation results were stored into database. It provided a good foundation for understanding the real-time status and variation rule of CNC machine tool.

Abstract: This paper presents a novel Rotary Steerable System which used a universal joint to avoid the alternating press in the drilling process. The mechanics model is established on the basis of simplifying structure and supporting of rotation axis in directive RSS. Dynamic model of the offset mandrel is derived by means of Hamilton principle, which could be used to control system design. Location of offset force acting on the offset mandrel is optimized and vibration equation of universal joint is deduced by means of transfer matrix method, then the results of natural frequency are compared with the calculated results of the finite element to verify the kinetic model. Both dynamic model and simulation analysis are expected to provide useful good guidance for the design of control system, detail design, structure optimization and the dynamic vibration of the RSS.

Abstract: The automatic generation of flow path is the key and most difficult task in Hydraulic Manifold Blocks (HMB) design. This paper divides the HMB layout space into grids, and sets the HMB boundaries and existing flow paths to obstacles, and the paths generated using maze algorithm are regarded as the initial population of genetic algorithm. The optimal path with the shortest path and least turnings can be obtained using genetic algorithm. The ports of flow path can be connected after the generation of technical holes based on the blind holes. The design parameters of holes, such as starting point coordinates, orientations and depths, can be obtained through a series of algorithms, and then drive the secondary development system HMBDesigner based on SolidWorks to generate three-dimensional solid model. This paper also discusses the generation method of multi-port flow path and multiple flow paths.

Abstract: The connection design of flow path is the most important task in Hydraulic Manifold Blocks (HMB) design. But the traditional method of feature design can not dynamically change the topology configuration and parameters of flow path when the design changed. This paper use a hybrid model consisting of temporary body model and B-Rep model, and represent flow path pattern using adjacency graph, adjacency matrix, weight matrix and degree array. The design parameters can be optimized by non-dominated sorting genetic algorithm (NSGA2). The topology configuration of flow path can adaptively change according to the design change.

Abstract: An analysis feature-based CAD-CAE integrated approach was proposed to solve the problems of rapidly CAE modeling for static and dynamic analysis process of machine tool. Firstly, analysis features were defined in CAD system and analysis feature library was constructed for machine tool and its structural components. Secondly, analysis feature model was constructed by attaching analysis feature to CAD model interactively. Finally, ANSYS parametric design language (APDL) file was generated automatically by mapping analysis features to APDL codes, which realized the integration of CAD system and ANSYS system. Based on application programming interface (API) of SolidWorks, a parametric CAD-CAE tool oriented to static and dynamic analysis of machine tool was developed, which realized parametric modeling and automatic analysis of machine tool and improved design efficiency and quality of machine tool.

Abstract: The modelling method of dynamic flow path feature (DFPF) is proposed for the design process of hydraulic manifold block (HMB). In this method, temporary body model and B-Rep model are adopted to represent geometric model of DFPF; the former is used for showing flow path, checking connectivity and safe wall thickness, and the latter is used for saving the final results. A novel feature topological representation method based on solid adjacency graph (SAG) is provided, and then validity of feature semantics can be checked through SAG. Finally dynamic topological changeability of flow path feature is realized by constraint solution and knowledge driving. Object-oriented model of DFPF is given, and the design process of HMB based on DFPF is illustrated.