Advanced Engineering Forum Vols. 2-3

Abstract: This paper presents a novel micro machining process that micro mill-grinding by combining micro-grinding and micro-milling. The principle of micro mill-grinding has been analyzed and a experiment is designed to study the influences in micro mill-grinding process on Al 6061-T6. The manufacturing is carried out on a desktop micro machine developed by NEU. In this research, analysis from results could found that the surface quality influences in micro mill-grinding is complicated affected both by milling and grinding, and conclude aspects such as cutter diameter, feed rate and material properties.

Abstract: To the matrix Riccati differential equation, based on dynamic design Variables Optimization Method, making unknown element of Riccati matrix as design variables, square sum of defined summation matrix element as objective function, a kind of new optimization Method about element of Riccati matrix orders is built. Universal program is formed. Practical examples are computed. Effectiveness is shown through result. The method is a new thinking for computing high order matrix Riccati Differential equation and obtaining control parameters.

Abstract: This study focuses on the natural frequencies of nonlinear free transverse oscillations of transporting tensioned beams via the standard fast Fourier transform (FFT). The transverse oscillations of transporting tensioned beams can be governed by a nonlinear partial-differential equation or a nonlinear integro-partial-differential equation. Numerical schemes are respectively presented for the two governing equations via the differential quadrature method. For each nonlinear equation, the nonlinear oscillations frequencies are investigated via FFT with the time responses histories. The numerical results depict the tendencies of the frequencies of nonlinear free transverse oscillations of transporting tensioned beams with the changing oscillations amplitude, transporting speed, the nonlinear coefficient and the flexural stiffness.

Abstract: The link rod butterfly valve relies on the link mechanism inside the flow channel to realize opening. The flow within flow channel is complex and the flow state is uncertain, so that pressure load of the flow part can't be determined in the butterfly valve designing, and strength of the parts can’t be calculated accurately and the thrust of the hydraulic cylinder can't be determined accurately. Therefore, it is necessary to carry out flow field analysis. In this paper, by adopting the plug-in COSMOSMotion of Solidworks software, the link rod butterfly valve with DN1800 is carried on motion simulation, determining the specific opening. And then the butterfly valve at different opening is carried out the finite element analysis of the flow field, adopting the plug-in COSMOSFloworks of Solidworks of software. The result shows that: the force is the largest when the valve plate is in just opening, it is 230731N, the strength analysis of the flow part and selection of the hydraulic cylinder should be based on the working condition; When full opening, the upward force on the valve plate is 18504N, this force is the power source when the valve plate is over opening. The above mentioned work provides a reliable theoretical basis for the strength calculation and the force and energy parameters calculation of the link rod butterfly valve and the theoretical reference for flow pattern evaluation of the link rod butterfly valve.

Abstract: Based on Newton method, the nonlinear differential equation of FSI vibration of hydraulic pipe on aero-engine has been established. The equation include visco-elastic coefficient, and the dimensionless equation was got. The influence of mass ratio, velocity of fluid and axial force on natural frequency of the pipe was researched by analyzing the FSI vibration equation of the pipe. The influence of fluid pressure on natural frequency was verified by experiment. And vibration response of the pipe was obtained by experiment at different driving frequency. The conclusion of the experiment was consistent with the result of the theory.

Abstract: The paper chooses ZLP800 temporarily installed suspended access equipment (TISAE) as a object of study, it is based on theory of structural model analysis. The finite element model has been established by the finite element method (FEM). The model is analyzed by the modal analysis module of ANSYS, the first four natural frequencies and corresponding modal shapes are extracted in this paper, the cause of every modal shapes are analyzed in the paper. In order to get a more rational constraint mode, the natural frequency under different constraint condition is calculated. Then the external excitation factors, such as the vibration frequency of the electrical machine in a hoister, swing of suspended platform and the friction disk in a hoister are calculated respectively, finding the external excitation factors which would cause a sympathetic vibration, and giving the suggestions for averting the sympathetic vibration, providing some academic reference to improve and perfect the structure design of the TISAE products.

Abstract: The dynamic design of a large belt conveyor with horizontal curves was studied in this paper. The method of calculating its running resistance was obtained by analyzing the orienting force and resistance on the curving parts of the belt conveyors. Dynamic equation of belt conveyor with horizontal curves by using discrete finite element model was established integrating the line-running parts and the curve-running parts. Additionally, dynamic analysis software of belt conveyor with horizontal curves was developed. Through simulation on real time system, start-up process and braking process were analyzed. The deviation of the belt was analyzed based on the tension, and the effect of curve running on belt conveyor was discussed.

Abstract: The disc-drum type rotors are commonly used in large gas turbine engines. In this paper, the dynamic characteristics of single stage disc-drum structure are studied based on the finite element model, where the connecting bolts are modeled using solid elements and the frictional contact at the joint interface is accommodated. In order to evaluate the nonlinearity resulting from the bolted joints, a finite element (FE) model fixing the disc and drum together is also established, and the simulation results based on the two models are compared. The effects of the bolt preload and the rotating speed on the dynamic characteristics of the disc-drum structure are also discussed. The works proposed in this paper help to enhance the understanding of the dynamics of the disc-drum type rotor.

Abstract: In this paper a horizontal vibration problem in strip rolling was studied; dynamic model was established; the mechanism of self-excited vibration was analyzed. The main reason of surface quality of strip is self-excited vibration. A vertical natural frequency and vibration mode of the rolling mill are obtained by finite element method. It lays the theoretic foundation for future researches on rolling mill vibraton.

Abstract: The intensity and rigidity of cross-roll pipe straightener frame are analyzed with the Finite Element Method (FEM) and the stress of the frame is tested. The FEM results are compared with experimental results and the accuracy and rationality of FEA results are verified. The analysis results have significant guidance to design and transformation the structural type of cross roll straightener and its frame.