Jian Ping Zhou

Study on Rules in Material Removal Rate and Surface Quality of Short Electric Arc Machining Process

Short electric arc machining (SEAM) is a non-conventional machining process that utilizes an arc to melt and vaporize workpiece material. A low voltage, high current supply is employed to produce a continuous arc in either a water-air mixed medium or in air. This paper describes an investigation into the optimization of the SEAM machining efficiency based on experimental design which considers both electrical parameters and machine parameters. The work uses the orthogonal experiment processes to research the influence of the process indicators on machining efficiency.

Static and Dynamic Analysis of Wind Turbine Tower Structure

This paper presents static and dynamic analysis of tower structure supporting a 600KW wind turbine based on the theory of FEM. According to the static and dynamic characteristics of tower structure, the works about simplified models and confirming loads and boundary condition are discussed. In static analysis, under different work conditions the load bearing capacity of tower structure is analyzed with door opening in different directions and without door opening. In dynamic analysis, in order to address the impacts of the foundation on structure, the research discusses the natural frequency and eigenmode from the first sixth modes at the assumption of fixed base and the elastic subgrade. Comparative studies have been performed on the results of the above analysis and some useful conclusions are drawn pertaining to the effectiveness and accuracy of the various models used in the work. Our research work lays a solid foundation of the further static and dynamic analysis.

The NC Power Supply Design of Large Current and Wide Frequency Pulse in Short Electric Arc Machining

There are a lot of ways to achieve large current pulse power supply, and the more common way is to adopt the inverter switching circuit to achieve pulse power supply. The core of the NC power supply design of large current and wide frequency pulse in SEAM is using two-stage modulation. Combined with inverter technology, DC chopper technology and NC technology, it not only can achieve the adjustability of the output pulse amplitude, but also can realize continuous adjustment of the output pulses and the duty cycle. The front stage of power supply uses DC/DC transformation circuit with the UC3879 integrated control chip as the core. With the microcontroller as the control core, the backward stage uses DC chopper circuit to achieve the NC power supply of multi-parameter adjustable output large current pulse.

Analysis and Study on Surface Quality of Workpiece of Short Electric Arc Machining Process

Owing to the Poor Surface Quality of Workpiece Processed by SEAM, the Work Used the Design Method of Orthogonal Experiment to Search for the Rules between Process Factors and Surface Quality of Machining. through the Range Analysis of Test Results and the Establishment of Process Regression Equation to Find the Rules between the Surface Quality of Workpiece and Process Factors, the Paper Provided the Test and Theoretical Basis to Achieve the Purpose of Improving the Surface Quality of Workpiece of Short Electric Arc Machining Process.

Three-Dimensional Numerical Simulation of Temperature Field and Force Field of T-Type Turbe during Welding

Residual stress affect the lifetime of weldments directly. Temperature Generated from the welding process is the major reason that influences the microstructure and mechanical properties of the metal weldments. Therefore it is necessary to simulate the temperature field for optimizing the structure of weldments. In this work the three-dimension finite element analysis software SYSWELS was used to simulate T-type tube, and carried on a detailed analysis of temperature field and residual stress in cool process of weld.

The Welding Track Planning and Motion Control of T-Type Tube Autowelding Machine

Combining with welding and numerical control technology, welding automation technology has brought the new development for welding equipment industry. This paper mainly aimed at automatic welding process needs for intersecting line of T-type tube, developed a practical automatic welding machine of T-type tube intersecting line, used the PCL893 movement control card as the core control unit, realized whole rotary feed of welding head and front and rear feed of the torch, etc. Integrating with mechanical cam and digital cam, the work achieved space fitting of saddle-shaped weld track so as to realize automatic welding process, imitate the manual welding process of space curve, reduce labor intensity, improve the efficiency of welding and quality.

Topping Height Automatic Control System of Cotton Top Cutter

Conforming the requirements of the agricultural machinery automation, the project combined with infrared sensor technology, codec technology, hydraulic transmission control technology, sensor technology and MCU control technology, developed a cotton top cutter of precision, fast response, strong anti-jamming capability, intelligent control. Intelligent cotton top cutter can replace effectively the chemicals topping and artificial topping. The machine of high automation and high precision can reduce effetely of apical dominance on cotton growing in the maximum extent. Intelligent cotton topping is of great significance on the management of cotton-growing and have a good role in promoting automation level of agricultural machinery

The Design of Welding Control System for Intersection of T-Tube's Seam Welding Based on the Multi-Axis

To improve the quality and efficiency of T-shaped pipe welding, a double-gun welding CNC is designed based on Multi-axis Control. The control program using Delphi software can accomplish system management and control functions. This system could display current status of each axis in real-time, complete automatic fault diagnosis, modify the welding parameters and so on.

Design & Realization of CNC System for Short Electric Arc Machine

Short Electric Arc Machining (SEAM) tools were devised for cutting high hardness and strength conductive material. For solution of short electric arc mechanism research and the needs of numerical control melt application, it was necessary to develop a short electric arc CNC machining. The paper introduced the peculiarity and types of the numerical control system’s software and hardware in nowadays. According to the requirement of short electric arc machine an open CNC system was developed in this thesis.

Dynamic Analysis of Wind Turbine Blade Based on Reverse Engineering

The dynamic analysis of the 750Kw wind turbine blade was presented based on Reverse Engineering. Because of complex shape, the model of wind turbine blade is a bottleneck of restriction development on the dynamic characteristic research of blade. The work attempted a new way to build the blade 3D model and completed the dynamic analysis. At first, the point cloud data of blade were gained using ATOS optical scanner. Secondly simplified, smoothed and partitioned in Imageware, point cloudy data were created into curves. Then the curves were imported into UG, the 3D model of blade was attained through curve fitting. At last the dynamic analysis of the blade was completed in ANSYS Workbench. The analysis adopted BlockLanczos method to extract the mode and get the natural frequency and eigenmode from the first to sixth modes. The paper ascertained the first and second wave eigenmodes, the first swing and the first torsion eigenmode. Calculations showed that eigenvalue of wave vibration and swing vibration were lower, torsion vibration eigenvalue was higher. In the vibration of the blade, the couple vibration of wave and swing taked major role, and the influences of torsional vibration were not great. The results showed the wave and swing vibration were predominated, the torsional vibration can be neglectful. The paper developed some new methods, established foundations for the further research of large wind turbine blade in the future.