Advanced Materials Research Vols. 383-390

Abstract: A new decoupling control structure is presented for complex special shape pipe welding process, which consists of model construction by reorganization method. Using this structure, an decoupling control system is established which realizes an adaptive decoupling control strategy for the welding processes with integrated complexities by using structure of decoupling control system and based on multivariable predictive function and nash optimization to making sure the right coefficient. Such system can be easily implemented on the welding peocess and simulation show this approach is effective.

Abstract: This paper analyzes the relationship between cutter parameters and gear profile parameters on the basis of rack cutter with asymmetric, and proves the new type gear can be manufactured by traditional methods. The meshing theory of involute helical gear with asymmetric is researched. Equation about involute profile helicoids is derived. The 3D model of involute helical gear with asymmetric is built, and the model establishes the basis of FEA of tooth root bending strength and tooth surface contact strength.

Abstract: To obtain the dynamic characteristics of the disc brake, the modal of the disc of brake is analyzed by finite element method and experimental method, the natural frequency and the vibration mode of the disc are obtained, the research shows that the result of finite element method is basically identical with the experimental method. The axial vibration of the disc and tangential vibration of the brake pad are tested by experiment method and the time domain charts are obtained, the main vibration frequencies of brake are studied, the vibration cause is analyzed and the corresponding improvement measures are put forward.

Abstract: According to the principle of induction heating, the skin depth of shrink-fit chuck is determined and the mathematical model of induction heating is constructed. Then a finite element model of induction heating for shrink-fit chuck based on FEM software is set up and the electromagnetic field, temperature field and structure field are obtained. In the end, the paper discusses the influence of the position, current frequency and current density of the coil on the deflection of the clamping bore. Research work provides a theory reference for the design of shrink-fit tool holder and shrink-fit machine.

Abstract: A novel sensorless control method of surface-mounted permanent magnet synchronous motor (SPMSM) based on high frequency (HF) current signal injection is proposed in this paper. A HF sinusoidal current signal is superimposed into the estimated d-axis, and the rotor position can be demodulated after q-axis voltage is regulated, which is relative to error angle. Ultimately sensorless control can be achieved. Theoretical analysis and simulation validation are carried out. The simulation results indicate that the rotor position and speed can be obtained exactly at low and zero speed. The approach ensures good dynamic and static performances, and can realize accurate position servo control.

Abstract: This paper is aimed to analyse contact stress of ring-plate indexing cam mechanism which is a new type of indexing cam mechanism. A contact finite element model of the cam and the pin gear is established with the commercial software of MATLAB and ANSYS. With the finite element analysis, the contact stress of the cam and the pin gear is predicted in one motion cycle. On the basis of the finite element analysis, the force and the position of maximum stress are obtained. The conclusion proposed here is reliable to instruct the design of ring-plate indexing cam mechanism.

Abstract: Worse than common vibration, resonance is a form of severe vibration. It is very important and useful to know what factors and conditions can result in resonance of flexible manipulators, when both link flexibility and joint flexibility are taken into account. In this paper, resonance analysis of the flexible manipulator with both link flexibility and joint flexibility is studied. Based on the flexible dynamic equations, main factors resulting in resonance of the flexible manipulator are analyzed. Furthermore, several conditions exciting resonance are derived and verified with numerical simulations. These conclusions are helpful to predict resonance and useful to the structure design and motion planning for a flexible manipulator to evade resonance

Abstract: According to the circumstance of soft plastic oscillating separator’s movement, a mechanical model of the mutual movement for material and screen is established, and reached the relative motion equation. Through building the mathematical model to optimize the parameter of the materials of different density that on the same vibrating screen, we can get the optimal parameter for the successful separation.

Abstract: Builds finite element model of a small pneumatic cylinder based on ANSYS, deals with the prets179, analyses the stress distribution character of a small pneumatic cylinder .Lastly, the calculation is compared with the test. It is shown that the finite element model of a small pneumatic cylinder with bolt pretension is agreed with the actual situation of cylinder.

Abstract: Methane storage data of clathrate hydrates formed in ternary system, methane-tetra-n-butyl ammonium bromide-water (CH₄-TBAB-H₂O), was measured by a magnetic suspension weight adsorption instrument at the temperature of 273.64 ~ 278.23 K and the pressure of 2.01 ~ 7.07 MPa, for two concentration (20.8 wt % and 43.3 wt %) of TBAB solutions. The hydrates component was qualitatively analyzed. The results showed that the structure of CH₄-TBAB semi-clathrate hydrates was deformed at high pressure possibly due to methane molecules replacing TBAB molecules and forming structure I true methane hydrates for the 20.8 wt % TBAB solutions at 273.64 K. For 43.3 wt % TBAB solutions, at the same experimental temperature and pressure, the maximum mass fraction of methane in CH₄-TBAB-H₂O clathrate hydrates was only 1.64 wt % which was less than the ideal maximum value (3.08 wt %). It showed that for the 20.8 wt % TBAB solutions, TBAB molecules were not replaced by methane molecules but both CH₄-TBAB semi-clathrate hydrates and structure I true methane hydrates were formed simultaneously. For 43.3 wt % TBAB solutions, the reason of low methane storage capacity may be that the pressure was not high enough.