Advanced Materials Research Vol. 823

Abstract: High-rise buildings constructed in large cities are thin and long in their shape and are both unconventional and light-weight. The purpose of this study is to reduce the across-wind response of high-rise buildings (unconventional) under the influence of wind load. As a means to change the external shape of high-rise buildings, we selected the flat Y-type form. It is generally applied in domestic high-rise buildings for examination. Wind tunnel tests take place on 12 high-rise buildings, composed of three different Y-type shapes such as basic square forms with square cross sections and unconventional forms, in a suburban area (α=0.15) with a turbulence intensity of 10%.

Abstract: nitial crack widely exits in the welded crane members. These cracks are induced by defect of design and manufacturing and effect of alternate fatigue stress. The fatigue performance and remaining life of welded components which have initial crack is significantly reduced. In the paper the typical box-type welded components of crane are discussed. Based on fatigue propagation experiment of box-type specimen with initially prefabricated crack, the fatigue propagation feature of Q235 steel is studied. Meanwhile finite element software Ansys is used to calculate the stress intensity factor. Combining experimental data and calculated result of stress intensity factor, two important propagation parameters of Q235 steel are acquired. The experiment result can be applied to evaluate the remaining fatigue life of welded crane members with initial crack.

Abstract: In order to calculate the grinding force of the basin-like grinding wheel in grinding outer race elliptical grooves, the thesis simplifies the grinding process as follow: the evenly distributed abrasive grains move around grinding wheel axis along an imaginary ellipse at high speed, while the imaginary ellipse moves along the trace deflected from the grinding wheel axis simultaneously. The analysis of grinding force in CVJ outer race elliptical groove grinding with basin-like grinding wheel reveals that, the grinding force will be decreased, if wheel velocity increased and feed velocity decreased. On the other hand, with the decrease of inter-grain spacing, the grinding force of basin-like grinding wheel will be increased, but the grinding force of abrasive grit will be decreased.

Abstract: The system configuration of CNC machine has nearly a thousand parameters to be set. These parameters are set correctly or not directly affect the use of CNC machine tools and their performance. It has been proved that the parameter setting about the CNC machine can bring much convenience to deal with troubleshooting and maintenance of CNC machine, reduce troubleshooting time and improve machine utilization. But for some parameters such as pitch compensation, position of reference points, these parameters settings are not in the same way in different machine. If parts of these parameters or all of these are lost, its unable to restore the precision of the CNC machine. It will bring great losses to the manufacturing enterprise. So the data of protection is particularly critical. This paper describes the function and principle about the machine data protection, and presents the method and step of data backup and recovery for the CNC machine with the typical CNC system, such as FANUC, Siemens and Huazhong CNC system.

Abstract: Nowadays, as a new type of optical fiber devices, with flexible structure characteristic and steady frequency-selecting performance among the key support device areas of optic fiber technology, Fiber Bragg Grating (FBG) is rapidly developed as an very important basic device.Therefore, the study of phase mask plate which will be good for the mass production of the optical fiber gratings is becoming a central issue. The appearance of phase mask plate technology makes the industrialized production of fiber optical gratings with a stable wavelength possible. This paper based on the optical fiber gratings written online is mainly about the study of related servo control system. By the design of the servo control system of phase mask plate, we will get the ideal purposes that phase mask plate is precisely positioned, torque of plate is increased and the time of picking any plate is undifferentiated.

Abstract: Vibration exists widely in people's life and production. Modal analysis for vibration system help to improve the running quality of the mechanical structure and prolong service life. This paper build a new discrete multi-freedom model to calculate the flexibility matrix of simple supported beam, and then use the flexibility matrix to calculate its modal parameters with matlab. In order to prove that the result is correct, this paper use classical continuous vibration theory to calculate the normal modal parameters, finding that the two results are basically the same and as the more discrete number, the result of discrete multi-freedom model more close to the result of continuous vibration theory. In view of this, the new discrete multi-freedom modeling method is proved to be true, and it also can provide the discrete modeling reference for modal analysis of complicated mechanisms.

Abstract: In the photoelectric detection technology,Often encountered in the detection and control of temperature.If the use of photovoltaic cells,Photoresistor,When the photodiode as a measurement of original,Because temperature of the light current or sensitive resistor, Therefore, if the requirements of high accuracy,Need to build circuit for temperature compensation on many occasions,For temperature control,Or independent testing to the temperature signal into the microcontroller,Through the system mathematical model associated with the temperature and temperature compensation of software,The last one is common ways.

Abstract: Machined surface texture is a very critical factor since it directly affects the surface quality and part mechanical behavior. In modern manufacturing system, it is necessary to develop systematic models, which can represent a realistic picture how the machined surface is produced during milling process. In this paper, a general geometric kinematic model is presented to build kinematic relationship between the arbitrary point of the cutter flute and the arbitrary point of the machining surface. And then, a nonlinear programming problem is constructed to calculate a scallop height along a normal direction of an arbitrary point on nominal part surface, three dimension profiles can also be simulated, a case is utilized to validate the feasibility of the proposed model.

Abstract: Precision forging of the helical gear is a complex metal forming process under coupled effects with multi-factors. The high forming load is required to fill the teeth corner, which significantly causes failure, plastic deformation and wear of dies. The maximum forming load during precision forging helical gear is calculated by the finite element method (FEM). Combining the FEM simulation results with the artificial neural networks (ANN), backward propagation (BP) neural network is trained using the data of FEM simulation as learning sample. The trained BP neural network is validated using test samples and used to predict the maximum forming load under the different deformation conditions. The results show that the predicted results agree well with the simulated ones, the differences of prediction results exhibit low value, the predicted precision satisfy the request of industry.

Abstract: Momentum theory model which was widely used in pitch control cant calculate wind turbine load, so it can't meet pitch control research needs of large-scale wind turbine. In this paper, the traditional model based on momentum theory firstly was improved to be able to calculate load under some hypothesis. Then the wind turbine model suitable for individual pitch control was built based on blade element theory. And wind shear and tower shadow on load of wind turbine was calculated and analyzed. Finally, the model was simulated in the turbulent flow conditions and load was analyzed by Bladed. Simulations indicate that the model built in the paper can be used in simulation and verification of individual pitch control, and the conclusions drawn by load analysis can provide theoretic basis and the reference standard for individual pitch control strategy.