Applied Mechanics and Materials Vol. 590

Abstract: The motion cycle chart of cam mechanisms of ATC was designed, the contour surface equation of globoidal indexing cam and the roller center trajectory equation of plane groove cam were established. Based on the idea of modular design and the SolidWorks, a CAD system of cam mechanisms of ATC was developed by using SolidWorks API and VC++ 6.0. Then the assembly model was built under the circumstance of SolidWorks directly. Meanwhile, the movement of cam mechanisms was simulated so that the reasonableness of the design was verified.

Abstract: This article gives an overview of the study on using the air-to-water heat pump (A&WHP) for heating buildings in cold climate regions. The study was conducted in a relatively cold region (59°N), where the ambient temperature during the winter usually falls below-20°C. Despite the fact the COP of the air-to-water heat pump in the winter period was 2.5 on average and during the heating season of 2013/2014 the additional energy requirement was less than 3%.

Abstract: It's not easy to achieve high-precision and wide range for the SAW temperature sensor. The multi-reflector reuse method is proposed in this paper based on the SAW delay-line theory. A pair of RF pulse query signals with difference query width are sent sequentially to the novel SAW sensor in a query period, the phase different of the RF pulse echo signal is analyzed based on the position factor. The novel method is used in the SAW sensor design, the SAW sensor can achieve the high accuracy and the well range at the same time.

Abstract: The UAV remote sensing is an important way of aerial remote sensing, and increasingly become an important means for spatial data acquisition, which has the advantages of long life time, image real-time transmission, high-risk area detection, low cost, flexibility, is a powerful supplement satellite and aerial remote sensing."Tianyi" series of UAV has a number of intellectual property rights, and repeatedly used in major natural disaster emergency in the country. Has the advantages of small volume, light weight, small target characteristics, the use of fast, flexible, convenient operation and repair, and can be widely used in the field of disaster prevention and mitigation, search rescue, traffic control, resource exploration, land resources monitoring, border patrol, forest fire prevention, crop monitoring, and provides an example of the application.

Abstract: The Effect of gap size to counter current flow limitation (CCFL) in vertical rectangular channel was studied in this paper. Experiment was conducted by using two vertical plate with 1 mm, 2 mm, and 3 mm narrow gap. The initial temperature of plate was decided at 600^oC. Flow rate and temperature of cooling water were controlled about 0.09 L/s and 90^oC respectively. Non-dimensional superficial velocity for water is 0.05-0.09 and non-dimensional superficial velocity for vapor is 3.20-3.2. The result shows that the existence of CCFL in the vertical rectangular narrow channels. A new correlation for CCFL base on Wallis has been proposed.

Abstract: Autonomous aerial refueling (AAR) can improve the long-distance and rapid strike capacities of an unmanned aerial vehicle (UAV) significantly by extending its range as well as loiter time. This paper has mainly studied on the measurement of refueling drogue during the docking phase of the probe-drogue UAV-AAR. Firstly, the monocular vision based drogue detection and recognition method is presented. Secondly, the measuring method of relative position between the drogue and UAV based on the model of camera calibration is researched. Finally, the semi-physical experimental system of drogue spacial location for UAV-AAR during short-range docking phase is constructed. The drogue measuring experiment based on monocular vision is implemented, and the performance of the monocular vision method for drogue measurement and the validity of the experimental scheme are verified.

Abstract: Faster and more accurate optical aspheric testing methods are required in many technical fields. A digital moiré phase shifting interferometer (DMPSI) with partial compensation lens (PCL) is proposed. With digital phase shifting technique, only one shot of interferogram is required, so the system structure is simpler with lower sensitivity to the environmental vibration. PCL is designed to enlarge the measurement range of asphericity. A DMPSI prototype in Fizeau configuration has been developed. After calibration, spherical surface is tested with accuracy comparable to Zygo interferometer.

Abstract: Effective complex permittivity measurements of materials are important in microwave engineering and microwave chemistry. This paper describes a convenient laboratory method designed to obtain the permittivity for some materials. The hole for temperature measurement has been designed. The permittivity of materials at deferent temperature can be measured. The measurement results of the real part and imaginary part of the permittivity agree well with literature data at 2.45GHz.

Abstract: A silver film-covered photonic crystal fiber containing different sizes of air holes is proposed to construct the surface plasmon resonance sensor. In this sensor, a nanoscale metal film and analyte can be deposited on the outer side of the fiber instead of coating or filling in the holes of the conventional PCF, which make the real time detection with high sensitivity easily to realize. Moreover, it is relatively stable to the changes of the diameter of air holes, which is very beneficial for sensor fabrication and sensing applications. The finite element method is used to analyze the characteristics of the surface plasmon resonance sensor. And the numerical results show that the resonance wavelength is sensitive to the refractive index of liquid, while the resonance wavelength doesn’t change basically when the diameter of air holes vary.

Abstract: With the wider use of metal welded structure in engineering machine, on-line inspection on weld crack is of great significance. This paper reports an emerging nondestructive approach----electromagnetically stimulated infrared thermography technique, for the detection and characterization of surface cracks. According to the electromagnetic thermal coupling analysis theory, different abnormal temperature field distributions caused by various crack dimensions , coil lifting heights, stimulated frequencies and paint film thickness were obtained, via 3D finite element analysis (FEA).The results show that the weld surface crack detectability are greatly influenced by the crack width and the paint layer thickness, with coil life-off height decreasing and electromagnetic excitation frequency increasing, the maximum abnormal temperature difference increases. There is a certain reference value for further research on the design of the electromagnetically stimulated control device.