Papers by Author: Gang Li

Abstract: In this paper, we present the modeling and dynamics simulation of a six-DOF tunnel segment erector for tunnel boring machine (TBM), which is performed in the virtual prototype platform. The 3D virtual assembling model of a tunnel segment erector is built based on Pro/E software according to its design parameters such as structure and size. After the interference inspection, the model is imported into ADAMS through the interface module of Mech/Pro. The model is simplified and optimized reasonably and various constraints are applied under variety working conditions. The results of simulation show that the design has six degrees of freedom movement capacity which meets the design requirements. At the same time the dynamics characteristics of drives and the forces of each part are obtained and they will provide a boundary condition for strength check and basis for the power system design which is important for the further optimal design.

Abstract: In order to solve the problems such as more restriction conditions, complicated interference and longer design periods in the design process of segment erector for Tunnel Boring Machine, it is necessary to study on the dynamics simulation of TBM segment erector. The 3D virtual assembling model of a tunnel segment erector is built based on Pro/E software according to its design parameters such as structure and size. The model is simplified and optimized reasonably and various constraints are applied under variety working conditions. The dynamics characteristics of drives and the forces of each part are obtained and they will provide a boundary condition for strength check and basis for the power system design which is important for the further optimal design. The simulation results also provide an important reference for the mechanism design and type selection design for the power system of segment erector and design cycle is shortened for TBM segment erector.

Abstract: The rock fragmentation process is the interaction process between TBM and rock mass, which is affected by TBM specifications, such as thrust force, cutter tip width and profile, cutter spacing, RPM, and torque, and rock mass properties mainly including rock material strength, rock brittleness, joint spacing and orientation. In this study, based on the systematic study of the existed rock constitutive model achievements and introduction of rock breaking mechanism, main failure mode of rock in the breaking process of disc cutter is added and revised in order to meet the actual situation. The method of establishing numerical model of disc cutter breaking process is introduced. After the dynamic simulation, we can obtain that geotechnical interface disturbance insulted by disc cutter. Based on plenty of experiments, it confirms reliability of numerical methods and provides a method to study cutting performance for different geological conditions.

Abstract: To obtain the reasonable layout and structure shapes of the various kinds of cutters in tunnel boring machine (TBM), the kinematic/dynamic of cutter head system was analyzed by using virtual prototype and finite element method (FEM). The velocity and force curves were got from different positions of cutters and the mode vibration of scrapers and cutter hobs were obtained to analyze their structural performances next stage. It is shown that these results can provide references for dynamic optimization design of tunnel boring machine. Therefore, it is necessary to implement kinematic/dynamic analysis and mode analysis before manufacture of production.

Abstract: In this paper, we present the design and implementation of a VRML multi-user layer, which is introduced in the virtual reality platform. A novel 3D simulation system supporting tunnel boring machine (TBM) design is developed. The virtual environment (VE) of the TBM is established by VRML based on virtual reality technology, the 3D assembling model is built by Solidworks software and changed into the virtual environment by VRML format. The optimal method is put forward by three steps optimization data to realize transmission of network. The motion simulation and virtual assembly program for TBM are made by VRML/Java language with the movement simulation control function to realize motion simulation. It has the advantages of free installation, authenticity, interactivity, low-cost, portability, and low requiring for the clients and so on.

Abstract: Aiming at the characteristics of structure and control of three-links hybrid machine tool, the interpolation strategy of CNC system is proposed in this paper. Coarse interpolation in workspace and fine interpolation in joint-space are expatiated. The trajectory points are transformed into discrete points by coarse interpolation mapping from workspace to joint-space. At the same time, the plans of trajectory, velocity and acceleration of discrete points in workspace are got, and then joint discrete points are realized by joint fitting smooth function. In order to meet the design demand and enhance effectively interpolation precision, the five polynomial interpolations will be thinning discrete points, and geometric locus will be very smooth.

Abstract: Abstract. As we all known, it is a hard and risky task to use a real physical tunnel boring machine prototype in experiment for the reason that it is expensive, complex and used in an special operating environment. Based on virtual reality technology, the function simulation of digital mockup using VR system is proposed, the function simulation of full-face Tunnel Boring Machine (TBM) based on Division Mockup is finished and verified by the consistency between theoretical study and actual simulation results. This paper provides the basis for design and improvement of product in order to reduce the production costs and time-to-market.

Abstract: It’s necessary to apply numerical prototype technology in developing processes of a TBM, and the application of VR system can enormously enhance the simulation effect. In the article, hardware configuration of a VR system for TBM motion simulation was discussed and the module function was analyzed. According to the practical working condition, motion analysis of TBM key components was carried out, and motion model was formulated. A model processing method using Deep Exploration and Creator was introduced, for transforming numerical models from CAD software to VR environment, and for dealing with the accompanying data loss. The article also discussed scene graph constructing method based on OpenGL Performer and developed a TBM motion simulation program.