Applied Mechanics and Materials Vols. 789-790

Abstract: This paper proposes a new method to predict the spindle deformation based on temperature data. The method introduces ANFIS (adaptive neuro-fuzzy inference system). For building the predictive model, we first extract temperature data from sensors in the spindle, and then they are used as the inputs to train ANFIS. To evaluate the performance of the prediction, an experiment is implemented. Three Pt-100 thermal resistances is used to monitor the spindle temperature, and an inductive current sensor is used to obtain the spindle deformation. The experimental results display that our prediction model can better predict the spindle deformation and improve the performance of the spindle.

Abstract: The object of the research is a thermoelectric generator installed in a liquefied natural gas gasifier. In this article the numerical estimation of parameters of thermoelectric generators (TEG) at cryogenic temperatures are presented and the experimental study of the thermoelectric properties of TEG at low temperatures as well as the outlook for using thermoelectric generators as a part of industrial liquefied natural gas gasifier has been carried out. In the process used heat transfer theory of cylindrical thin wall with a one-sided fins and the estimation of thermoelectric performance of TEG. As a result the experimental work has been investigated by TEG parameters at cryogenic temperatures; the evaluation of TEG number to produce electrical energy has been considered.

Abstract: Inspection feature recognition is one of the key technologies to realize system integration of CAD/CAIP. To improve the integration between design and inspection, an inspection feature recognition system is developed based on Pro/TOOLKIT and VS2008. The component factors of inspection feature were discussed in this paper, and the flow of inspection feature recognition was introduced. Finally, with a case study, the feasibility and applicability of the method was verified.

Abstract: It is important to evaluate the 3D crack behavior in the structures. In this study, a Crack-growth test and two simulations namely, Real-model simulation and Ideal-model simulation were performed using eXtended Finite Element Method (XFEM) to evaluate crack behavior three-dimensionally. In the Crack-growth test, crack behavior was observed for a notched metal specimen. In the Real-model simulation, the FE model was constructed using a 3D reconstruction model of the specimen, and crack growth was simulated. In the Ideal-model simulation, the simulation was performed using the FE model that involved ideal notch. The obtained crack growth simulation results were compared with tension test result. Crack growth in the specimen was evaluated three-dimensionally. It was shown that modeling the real shape of a structure with a crack may be essential for accurately evaluating 3D crack growth.

Abstract: Mixed convection flow and heat transfer characteristics in a lid-driven cavity with two isothermally heated circular cylinders inside are studied numerically using a finite element formulation based on the Galerkin method of weighted residuals. The top lid of the cavity is moving rightwards with a constant speed. The two cylinders are maintained at an isothermal hot temperature, while the walls of the cavity are maintained at a cold temperature. Comparisons of streamlines, isotherms and average Nusselt number are presented to show the impact of the Richardson number, non-dimensional radius of the cylinder, and the location of the cylinders on the transport phenomena within the cavity. The results of this investigation show that the presence of the cylinders results in an increase in the average Nusselt number compared with a case with no cylinder. The average Nusselt number increases with an increase in the Richardson number for all non-dimensional radius of the cylinder studied in this work. It is seen that changing the boundary condition on one of the cylinders from isothermal to adiabatic has minimal effect on the average Nusselt number around the walls of the cavity.

Abstract: An investigation has been done to numerically simulate the radiation losses which occur due to laser energy deposition in a domain. Although the fluid dynamic effects due to laser energy deposition has been studied by a number of researchers independently but the effect of radiation has either been neglected or has not been highlighted effectively. When laser energy is deposited in a domain, very high temperatures are reached. At such high temperature, the diatomic air species may become highly dissociated and emission from the resulting two mono atomic species N and O cannot be neglected and is the major source of radiation loss. An Open Source CFD software Open Foam has been used to study the above effects. P1 radiation model along with radiation Line by Line method has been used to calculate the radiation losses. Radiation losses obtained are 20 times higher as compared to the only one past reported data but still are negligible as compared to the deposited energy. Hence our study validates the assumption of neglecting radiation losses, which was assumed earlier in all previous studies without any proper validation, using the most accurate LBL method.

Abstract: High-precision machining and large-scale tool are the most primary development trend of current machine tool and hydrostatic products are key technologies of high-precision machining equipments. However, these equipments mostly process miniature components, thus the adopted tools are relatively small and the spindles mainly use are mainly built-in types of HSK32 to HSK25 with revolutions speed over 25,000rpm. Some processing equipments are even equipped with hydrostatic or gas-static spindles. The study extends the axial oil chamber to radial ones to expand the action area of axial oil pressure and form a closed oil seal edge by combining the radial clearance. Consequently, the axial bearing stiffness can be enhanced to enlarge the application scope of hydrostatic spindle. The design mode can enhance axial stiffness of spindle modules or strengthen the stiffness of hydrostatic spindle in a ball screw.

Abstract: CAD / CAE model of plate structure is designed for plate heat exchanger provided by the manufacturer. Stamping process of the plate is simulated using Dynaform which is the special software of numerical simulation for sheet metal. The quality of plate stamping is analyzed by thinning rate, forming limit diagram (FLD) and other indicators, and compared with practical problems. At the same time, twelve levels experiments programs including ripple inclination, ripple normal pitch and ripple height are established according to uniform design principles based the parameters of ripple structure provided by manufacturer, and twelve chevron ripple plate models is established and their forming quality is analyzed with Dynaform Software. Influence and laws of plates three structural parameters, plates’ section parameters , BHF for stamping quality are studied and summarized, and the optimal choice of the plates is fond out to provide a theoretical basis for the actual production.

Abstract: This work presents the framework to optimally design a cantilever for torsion mode frequency maximization. A cantilever design problem is formulated by topology and shape optimization methods. The torsion mode frequency is selected as an objective function, and the volume of the cantilever and the first bending mode frequency are constrained. Two optimization problems are defined and sequentially solved for the specific values. A new idea in this work is using a final topology obtained in the topology optimization problem as an initial shape in the shape optimization problem. The torsional mode frequency of the optimized cantilever is well improved in comparison with a nominal cantilever.

Abstract: The speed increasing gearbox is the key part of the wind turbine and its role is to transmit power which is generated by wind turbines to the generator through the gear system. The single-stage planetary gears train system is commonly used in the semi-direct drive wind turbines. In this paper Pro/E is used to establish the three-dimensional model of the speed increasing planetary gear system of the semi-direct drive wind turbine. Motion pairs, drive and load of the model are added by ADAMS. Angular velocity change rule of the parts is obtained. The change rules of the mesh force of the planetary gears, ring and sun gear can be obtained through the dynamic simulation and analysis using the contact algorithm. These are useful to study the vibration and noise of the system.