Jiang Hua Ge

The Research on Milling Temperature and Heat Deformation of Tool in Virtual Numerical Control Simulation

Joint modeling of exponentially fitting and least square method was proposed for key technical problems on milling temperature and heat deformation of tool in virtual numerical control (NC) simulation. Mathematic model of surface temperature and its influencing factors based on ball-end mill was established. Correlation coefficients of model are over 0.8, and the errors comparing with the experimental ones are within 10%, which shows that the model meets precision requirement, and fitting effect is good. By this model a mathematical model of the ball-milling cutter’s thermal deformation was established, and the relative error is small by comparing with test values, which proves that this model has high calculation precision and practical meaning. A simulation prediction system of milling temperature and ball-end mill’s heat deformation in virtual NC was developed based on above mentioned models, which can provide theoretical basis for machining error prediction, optimizing milling parameters and improving machining quality.

Study on Three-Level Matching Model of Product Configuration Oriented to Mass Customization

This paper proposed configuration three-level matching model based on modular product structure in order to solve the product configuration design problem in mass customization (MC). According to the product structure and the features of configuration design, the model divided the configuration course into three parts as first-level complete matching, second-level similarity matching and third-level correlation matching. Firstly obtained standard module that meets clients’ demands by retrieval algorithm of first-level complete matching and similar module of the customized by mathematical model of second-level similarity matching. Then based on them, analyzed the correlation matrix among modules and associated attributes of modules interface, and established the mathematical model of third-level correlation matching and realized the optimum combination of modules. Finally, verified the model by examples. The results indicate that this model could effectively solve the low-efficiency problem of deformation module recombination design in traditional product configuration so to rapidly respond to clients’ customization demands.

Journal Bearing Rotor Speed Effect on Dynamics Coefficients and Film Pressure

The dynamic coefficients and film pressure effect in rotor-bearing systems may lead to an unstable station. The mechanism of the dynamic coefficients and film pressure induced thermal instability in the rotor-bearing system has been studied. The journal bearing model is adopted for the derivation of analytical expressions. The results show that the rotor speed has some effect on bearing dynamic coefficients and film pressure.

Simulation on Cutting Temperature during Milling Aluminum Alloy 7075- T7451

Based on the finite element analysis software AdvantEdge, a simulation model for the milling process of aluminum alloy 7075-T7451was established to research the cutting temperature. This simulation model predicts the temperature distribution of work-piece and cutting tool, and the temperature variation trend along with the milling speed and rotational speed. The simulation results provide valuable references for researching on machining mechanism.

Research on Method of Rule and Structure-Based Product Configuration Design

Considering the problem of weak relational expression between the components and parts leads to low configuration efficiency, which is based on structure product configuration, this paper proposes a combination of the rule and structure method. In the modeling process, this paper uses structure-based configuration method to describe structural information and rule-based configuration method to describe the restrained relation of components and parts, and enhances the constraint of the parts. In the solving process, this paper uses two-stage sequential searching method to search, and improves the ability of solution. Finally, this paper takes reducer as an example to demonstrate the feasibility of the proposed method.

Research on Customer Requirements Expansion Based on TRIZ and Grey Theory

To accurately understand the current customer requirements, mine and predict those of potential market, requirement expansion method based on TRIZ was proposed to realize horizontal expansion of customer requirements and grey theory was applied to vertical expansion to maximize the diversity of customer requirement. Meanwhile, ontology model of customer requirements was built to represent in detail complete information of customer requirement, it provided the basis for determining product family reasonably and comprehensively.

Research on Modeling of Ball-End Cutter for Virtual NC Machining

In this paper, a new mathematical model and modeling method of ball-end milling cutter which satisfies the request of physical simulation in virtual NC machining system are proposed. The accurate expressions of the cutting edge are presented. The precise functional surface model of ball-end cutter is developed. And the 3-D visualization for ball-end milling cutter in virtual NC machining is implemented. The model can provide necessary and accurate geometric information for physical simulation and has been applied in milling force simulation. It laid the foundation for integration of geometric simulation and physical simulation.

Research on Parameters Optimization of Virtual NC Milling Based on Parallelism Selection Genetic Algorithm

To resolve key technology of parameter optimization of virtual NC milling physical simulation system, a multi-objectives optimized model was set up by non-linear programming theory and resolved by improved parallelism selection genetic algorithm. It was optimized when milling characters are sufficiently considered and machine quality was guaranteed. Sub-population size is decided by weighting each optimized object and calculating adaptation to assure importance of optimized objects and fasten convergence velocity. A kind of software that can optimize milling parameters of virtual NC was developed, and optimized strategy and validity of algorithm are verified which provides technology support for realizing virtual NC milling physical system.

Product Rapid Design for Customer Individual Requirements

Based on product configuration and modular design, a product rapid design method for customer individual requirements was proposed. Aiming at the product configuration correlation of this product rapid design method, we classify the product in accordance with the product functional modular classification principle, define the correlation between the functional modules, set up the correlation matrix between each module and recognize the customer demand of individual product configuration immediately by using the exclusion algorithm. At last, taking multimedia LCD projector as paradigm, we verify this method.

Modeling and Simulation of Milling Force in Virtual Numerical Control Milling Process

A parameter equation based on cutting edge of ball-end mill is set up by analyzing the parameters of ball-end mill influence the milling force in virtual NC milling process. The relationship among elemental cutting force, instantaneous radial chip thickness and cutting edge length is analyzed, and the dynamic milling force of ball-end mill at arbitrary feed direction is established. The milling force parameter model by quadratic regression equation in different cutting conditions is built. Through experiments in NC machining center and using orthogonal combination and principal components analysis, the regression coefficients are calculated. The correctness of milling force model is testified by experiments. All these can provide theoretical basis for physics modeling and simulation of virtual numerical control milling.