Abstract:The Article introduces the structual characteristic of flexible Coupling，explains their application and mechanism at multi-component force calibration device. When the multi-component calibration device force to transducer, some transmutation will be take placed between them, the veracity will be affected. The function of flexible Coupling is get over the effect. The article introduces technique design, applications effect and validate examination of flexible Couplings which are used in the multi-component force calibration device.

Abstract:At present, the method of visual judgment based on standard pattern is mainly used to analyze the shape of the leading and trailing edges of the processed blades. There are some problems such as low measuring efficiency, poor repeatability and inconsistent evaluation results. In this paper, a method for judging the shape of the leading and trailing edges based on the trend of thickness deviation is presented. The blade edge thickness is divided by the arc of the blade section. According to the maximum thickness deviation, the maximum thickness deviation ratio and the variation coefficient of thickness deviation in the evaluation area, the shape of the cutting edge of the leading and trailing edges of the blade is automatically analyzed. This method has fast and accurate characteristics and provides an important guarantee for the evaluation of engine blade processing quality.

Abstract:Restricted by the size and structure of the temperature and humidity standard box, the ventilation psychrometer will have a great impact on the humidity field in the verification process. A three-dimensional steady-state calculation model with equal proportion was established. The component transfer model and SIMPLE algorithm were used to simulate the humidity field in the verification process. The distribution characteristics of the humidity field were analyzed, and the scientificity and accuracy of the simulation results were verified by experiments.

Abstract:Tuning fork optical fiber integrated three-dimensional resonant probe is a new type of probe used in micro-nano coordinate measuring machine, which consists of stone tuning fork and optical fiber rod measuring ball. In order to maintain the vibration stability and measurement accuracy of the probe, the length of the rod is limited to less than 1 mm, which results in the limitation of its ability to measure larger aspect ratio microstructures. In order to guarantee the measurement performance of the probe and further improve the measurement capability of the probe, the probe was optimized and improved, and the performance test experiment was carried out.

Abstract:A vertical thermal diffusivity measuring device based on laser flash method is introduced. The device uses pulsed laser to uniformly heat the sample, which generates one-dimensional heat flow inside the sample. The temperature rise signal of the sample is measured by infrared detector. The temperature environment is measured by vertical vacuum heating furnace, and the thermal diffusivity is measured from room temperature to 1600 °C. A stainless steel sample with a thickness of 1.1 mm and a diameter of 10 mm is measured using this device. The deviation between the measurement results and PTB reference data is less than 1%.

Abstract:In order to solve the problem that it is difficult for traditional measuring equipment to accurately measure the combined block, a digital measuring method of blade die based on CMM is proposed. The theoretical values and vector directions of the points are automatically acquired by PC-DIMS measurement software. The coordinate system is established by iteration method. The corresponding scanning trajectory generation mode is selected, and the appropriate scanning density is set to measure the blade die, and the results are compensated in three dimensions. Using this method, the profile measurement experiment is carried out, the profile deviation diagram of blade die is drawn, and the uncertainty of measurement is evaluated. Experiments show that this method has good accuracy and high automation. It can accurately reflect the wear situation of blade die in the trial production and use stages. It provides an important reference for the repairing and maintenance of the die.

Abstract:In this paper, taking the single-axis test turntable system as the research object, the overall control scheme of the system is determined according to the technical requirements of the system function and performance, the key components are selected and matched, and the relevant mathematical model is established. At the same time, according to the dynamic test requirements of the system, the frequency domain characteristic method is used to correct the system and design the PID controller. The effectiveness of the control algorithm is proved by MATLAB simulation. At the same time, through the debugging in practical engineering, the positioning accuracy is not more than 2″, and the speed accuracy and stability are not more than 5×10-3. The operating frequency band is 10Hz and the amplitude error is less than 10%. This makes the system meet the requirements of the index and achieve the desired control effect.

Abstract:The positioning accuracy requirement of mobile measurement system is expounded. The three methods of positioning accuracy evaluation including the circular probability method, mean square error method and median error method are analyzed and compared. The positioning accuracy test of vehicle-mounted GNSS/INS is carried out in the standard test field. Experiments show that the evaluation result of the median error method is the most accurate, and its error is less than 1 m, which is obviously better than the circular probability method and the mean square deviation method.

Abstract:In order to study the correction method of instrument coefficient of cylindrical gear meter that works in hydraulic oil under variable pressure conditions, the gear flowmeter is calibrated at different pressure conditions with the flow standard facility which works with hydraulic Oil. Two methods of fitting with binary surfaces are used to fit the calibration results, and the error of the meter coefficient after corrected by two methods at each condition is less than 0.4% by the fitting correction, and it’s sure that the correction methods are useful.

Abstract:The test research method is the most direct and persuasive research method for railway vehicle energy absorbing advice crash-worthiness. In view of the current situation that few domestic literatures studied energy absorbing device crash-worthiness by test, a quasi-static test method is designed for railway vehicle energy absorbing device and carried out on some metro train energy absorbing device, the two key characteristics of compression force and compression stroke for energy absorbing device are obtained. According to the test boundary conditions, the equivalent simulation analysis model is established, the crash-worthiness of the energy absorbing device is studied and simulation results is compared to the test result. The research result shows that the designed quasi-static test method is feasible and can meet the needs of practical engineering. The simulation result is in good agreement with the test result, which verifies the accuracy of the analysis results and the validity of the test method, the combination method of test and simulation analysis provides theoretical and experimental support for energy absorption characteristics and subsequent structural optimization of energy absorption device.

Abstract:This paper briefly introduces the overall structure of aircraft-engine test cell and the thrust measurement method of engine installed on aircraft., the thrust measurement system and calibration method are described in detail. It analyzes the influence factors of the aircraft-engine thrust measurement, the correction methods of the measurement results and the shortcomings of the current calibration methods. Several improvement measures such as installation calibration, left and right platform joint calibration, servo loading calibration and in situ calibration are proposed, the calibration accuracy of aircraft-engine thrust measurement system and the measurement accuracy of engine installed thrust are improved. For other similar equipment calibration also has important reference and reference value.

Abstract:This paper briefly introduces the overall structure of aircraft-engine test cell and the thrust measurement method of engine installed on aircraft., the thrust measurement system and calibration method are described in detail. It analyzes the influence factors of the aircraft-engine thrust measurement, the correction methods of the measurement results and the shortcomings of the current calibration methods. Several improvement measures such as installation calibration, left and right platform joint calibration, servo loading calibration and in situ calibration are proposed, the calibration accuracy of aircraft-engine thrust measurement system and the measurement accuracy of engine installed thrust are improved. For other similar equipment calibration also has important reference and reference value.