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2018 Vol. 38, No. 2

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2018, 38(2): .
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2018, 38(2): .
Abstract(605) PDF(385)
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Study on Fracture Behavior of the Brazilian Test of PBX Explosives Based on XFEM
DAI Kai-da, LI Sheng-tao, CHEN Peng-wan
2018, 38(2): 111-117. doi:10.15918/j.tbit1001-0645.2018.02.001
Abstract(930) PDF(933)
Abstract:
In order to investigate the effects of different loading methods in the Brazilian test on indirect tensile mechanical behavior of PBX explosives,the deformation,damage and failure process in the Brazilian test,the arc Brazilian and the rubber-cushion Brazilian tests were simulated by using extended finite element method(XFEM).The distribution of displacement and stress were obtained.The effects of different loading methods on mechanical response,deformation and fracture were analyzed.The results show that the fracture path and the distribution of displacement and stress agree well with the experimental and analytical values.Compared with the Brazilian test,the arc Brazilian test and the rubber-cushion Brazilian test can reduce contact stress and help to prevent the generation of secondary cracks.It indicates that the rubber-cushion Brazilian test is better for measuring the tensile strength of PBX.
Experimental Investigation on the Performance of Polyurea-Coated Structure Under Blast Loads
ZHAO Peng-duo, ZHANG Peng, ZHANG Lei, WANG Zhi-jun, WANG Qi, XU Yu-xin
2018, 38(2): 118-123. doi:10.15918/j.tbit1001-0645.2018.02.002
Abstract(1033) PDF(801)
Abstract:
The blast-resistance capacity of different polyurea-coated plates and box structures subjected to blast loads was investigated. For polyurea-steel plates,two methods were adopted:steel plates of three thicknesses(2.0,1.5 and 1.2 mm) and two types(no polyurea and with polyurea on the front face)with the same areal density of 15.7 kg/m2were considered under explosive loading by 40 g TNT; steel plates of two thicknesses(1.5 and 1.2 mm) and three types (no polyurea,with polyurea on the front face and with polyuria on the back face)with the same steel thickness respectively were subjected to 60 g TNT. Then experiments of polyurea-steel box under implosive loading were conducted by 140 g TNT.Deformation and failure were compared with each event and effects of polyurea coating on the performance of structures were analyzed further.Results from the experiments reveal that polyurea coating does not contribute to the performance of steel plates with the same areal density,while polyurea coating can improve the blast resistance of steel plates and steel boxes with the same steel thickness under explosive and implosive loading. And polyurea cast on the back face exhibits better performance than that on the front face.
Stability Analysis of the Interfacial Debonded Crack in Solid Rocket Motor Grain with theJIntegral
SUN Bo, DUO Ying-xian, MENG Shang-yang
2018, 38(2): 124-129. doi:10.15918/j.tbit1001-0645.2018.02.003
Abstract(864) PDF(413)
Abstract:
In order to investigate the stability of the case/insulation,insulation/cladding,cladding/propellant interfacial cracks in the solid rocket motor (SRM) grain when it was lunched,the three-dimension viscoelastic finite element models of the SRM with interfacial cracks were established.The singular interfacial crack elements were included in the 3-DJ-integral loop surface to improve the calculation precision.The three-dimension singular interfacial crack elements at the tips of debonded cracks were established to simulate the crack propagation along the bonded interface.Along the interfacial crack propagation,theJ-integral of the interfacial crack tips variation with the debonded length and position were calculated to prejudge its stability.The results show that the maximalJ-integral value of the interfacial cracks is located in the position where corresponds to the fore slot of SRM grain.And theJ-integral value of the interfacial cracks is monotony increasing with the debonded length.Then the interfacial cracks should be expanded instability at a certain debonded depth.
Shock Reduction Characteristics Caused by Material Parameters of Separation Plate in Super*Zip Separation Joint
LI Kang, LIN Yu-liang, CHEN Rong, SUN Jing, ZHANG Zhi-feng
2018, 38(2): 130-136. doi:10.15918/j.tbit1001-0645.2018.02.004
Abstract(806) PDF(392)
Abstract:
Super*Zip separation joint is a typical linear pyrotechnic separated device.This article focuses on the influence on shock reduction of failure strain and yield strength of the separation plate.The numerical simulation analysis was made using the LS-DYNA fluid-solid coupling algorithm.Results show that the shock response of the separation system is quite sensitive to failure strain and yield strength of the separation plate.Specifically,shock response of the separation system is 163% and 61% of the original state when failure strain is 125% and 75% of the origin parameter,while it is 150% and 87% of the original state when yield strength is 120% and 80% of the origin parameter.
Experimental Study on Low-Speed Dynamic Response of Combined Aluminum Honeycomb
LI Xiang-cheng, LIN Yu-liang, LU Fang-yun
2018, 38(2): 137-142,172. doi:10.15918/j.tbit1001-0645.2018.02.005
Abstract(1007) PDF(1011)
Abstract:
By impacting experiments with low speed in an improved SHPB system,force was measured with a PVDF sensor and displacement was obtained by a laser system in an in-situ measurement way.As a result,curves between stress and strain were obtained.The properties of buffer and energy-absorbing of combined aluminum honeycomb was discussed using high-speed photography.The results show that the whole process can be divided into two stages:the inserting process between up-down honeycombs and the conjunctly crushing process;the joint happens in the strain of about 0.5.Besides,there are two peaks of about 40% in the effective energy absorption curves and the energy-absorbing property is better in the condition of dynamics.
Research on SCR Urea Injection Method of Diesel Engine
YUE Guang-zhao, LIU Xing-hua, SUN Bai-gang, QIU Tao, YAO Xiao-gang
2018, 38(2): 143-149. doi:10.15918/j.tbit1001-0645.2018.02.006
Abstract(790) PDF(402)
Abstract:
The characteristics of urea injection and NOxconversion efficiency are closely related.A SCR test bench was built based on V2O5-WO3/TiO2catalyst,and NO,NH3and O2feed streams were dosed by mass flow controllers.The effect of normalized stoichiometric ratio (NSR) and catalyst temperature on ammonia storage,ammonia slip and NOxconversion efficiency was studied.The results show that the influence of NSR and temperature on ammonia storage,ammonia slip and NOxconversion efficiency is obvious.The time of ammonia storage will be shorten with the increase of NSR,then the improving speed of NOxconversion efficiency is high.The NSR fix 2.2,the NOxreduction efficiency increase from 0 to 4.3% within 15 s,and the NOxreduction efficiency increase from 0 to 8.7% within 15 s when NSR set 3.0.The time of ammonia slip and ammonia storage are closely related,the time of ammonia slip will be shorten with the increase of NSR.The method of NSR from larger to the smaller can increase ammonia storage rate and optimize NOxconversion efficiency.Using this injection method to carry out the European transient cycle(ETC) test,the brake specific emission of NOxreduce from 8.26 g/(kW·h) to 1.91 g/(kW·h),and the average and peak value of ammonia are 5×10-6and 18×10-6,the NOxcan reach the National V emission regulations.
Theoretical Basis and Simulation Analysis of Eddy Current Array to Cracks Defection
YUE Ming-ming, ZHANG Wei-min, PANG Wei-han, XU Min-dong
2018, 38(2): 150-154. doi:10.15918/j.tbit1001-0645.2018.02.007
Abstract(975) PDF(537)
Abstract:
The high detection efficiency of eddy current array detection technology makes it suitable for large areas scanning.Based on a systemic research on the eddy current array detection device developed independently,the theoretical basis of this work was studied for further applications,and simulation analysis with the FEM software COMSOL was carried out on the system.The simulation results show that,the estimating of surface crack defects on the conductor can carry out quickly and effectively.The eddy current array detection method plays a significant part in the evaluation of crack defects,can promote the technology development and practical efficiency of actual cracks detection.
Study on Terrain Classification Based on Vehicle Suspension Vibration
ZHAO Kai, DONG Ming-ming, ZHAO Feng, QIN Ye-chen, LIU Feng, GU Liang
2018, 38(2): 155-159. doi:10.15918/j.tbit1001-0645.2018.02.008
Abstract(856) PDF(467)
Abstract:
In order to improve the terrain classification performance using the vibration response induced in suspension of a traversing vehicle on natural terrains,a new feature vector extraction method was proposed by combining time domain features and wavelet packet energy features.The probabilistic neural network(PNN)was utilized to perform classification,comparing the classification effect of the combined feature vector with the other two traditional ones.A road simulator was employed to perform the excitations of the presented six roads.The vibration data was collected by a single axis accelerometer mounted on the suspension arm perpendicular to the ground.The results indicate that the proposed method can result in a satisfactory classification accuracy of 91.3%,which outperforms the other two traditional ones.
Experiment and Research on New Respiratory Type of Fresh Air Device with Heat Recovery Function
WANG Qiu-shi, ZHENG Hong-fei, WU Gang
2018, 38(2): 160-164. doi:10.15918/j.tbit1001-0645.2018.02.009
Abstract(676) PDF(498)
Abstract:
In this paper,a new respiratory type of fresh air device with heat recovery function was designed to reduce the building energy waste.Its process was arranged to save part of the heat energy in the exhaust gas and send it back to the room,when supplying fresh air with a heat storage device installed in the ventilation duct.Firstly,the work principle and the performance test method were introduced.Then,two kinds of situations,such as winter heating and summer cooling,were respectively simulated in a simulation room to test the temperature variation regularity of the heat storage device,heat transfer efficiency and energy saving.The experimental results show that,the ventilation of the device can reach 60 m3per hour,fresh air thermal load can be reduced about 280 W in winter and the fresh air cooling load can be reduced about 270 W in summer,its heat recovery efficiency can reach 80%.
Spatio-Temporal Adaptive Mixture of Gaussians for Moving Objects Detection in Complex Background Scenes
ZHU Wen-jie, WANG Guang-long, TIAN Jie, QIAO Zhong-tao, GAO Feng-qi
2018, 38(2): 165-172. doi:10.15918/j.tbit1001-0645.2018.02.010
Abstract(1265) PDF(694)
Abstract:
To effectively resolve the problem of moving objects detection in complex background scenes and overcome the disadvantages of the traditional single-pixel based modeling method,spatial information of video image sequence was introduced into background modeling process.Several methods were studied,including neighborhood updating,two-dimensional joint histogram information entropy judgment,spatio-temporal smoothing etc.Firstly,video images were pre-processed with guided filter algorithm to remove noise and preserve edge information of the interested objects.And then,implementation procedure and processing steps were presented.Finally,some qualitative and quantitative experiments and comparison analysis were carried out based on different benchmark datasets and reality video frames.Results show that,the proposed method outperforms other traditional methods for moving object detection.The method provides a novel approach for the problem of moving objects detection in complex scenes.
Rotation Demodulation of GNSS Signal in Rotating Projectile Fuze
XIAO Hong-bing, PAN Hai
2018, 38(2): 173-178. doi:10.15918/j.tbit1001-0645.2018.02.011
Abstract(717) PDF(346)
Abstract:
In order to solve the incorrect positioning problem of satellite orientation receiver caused by the rotating and high dynamic process of rotating projectile,a positioning signal receiving method for rotating body satellite was proposed.Firstly,the effect of rotation condition on the satellite positioning signal reception status was analyzed detailedly;and then,a rotating tracking demodulation loop was designed for rotation tracking and demodulation,and a rotating body satellite positioning signal receiving system was designed;finally,the system was simulated with Simulink and the corresponding simulation and experimental results were achieved.The results show that the rotating body GNSS receiver based on the track loop can get a track range up to ±40 Hz,in the case of 200 Hz center frequency,which can meet the requirements of rotating body tracking about 200 rev/s.
Research on the Control System of Cross Typecanards Ammunition
HE Guang-lin, ZHANG Jia-shuo, GUO Ya-chao, YANG Jiao-ying, ZHANG Zhan
2018, 38(2): 179-182. doi:10.15918/j.tbit1001-0645.2018.02.012
Abstract(781) PDF(405)
Abstract:
To solve the problem of low killing efficiency of submunition,a kind of cross-shapedcanard bullets and its control system were proposed,analyzed and designed.For the problem of rotating submunition,the generation principle of the control force of submunition charge was analyzed,and the method of cycle average control force was put forward.To verify the flight stability of submunition,the Matlab software was used to do a simulation of the flight path without control.The horizontal displacement of submunition was 450 m,and the angle of attack was within 0.4°.Due to the strong coupling effect of submunition control channel,a pre-feedback compensation method was designed to decouple su bmunition and a PID controller was designed to simulate the control effect.Research results show that the coupling effect almost disappeares after decoupling.
Roll Control Response Model of the Dual-Spin Trajectory Correction Component
YIN Ting-ting, JIA Fang-xiu, YU Ji-yan, WANG Xiao-ming
2018, 38(2): 183-189. doi:10.15918/j.tbit1001-0645.2018.02.013
Abstract(1001) PDF(607)
Abstract:
In order to improve the attacking accuracy of the firing range test,an actuator roll control response model of the dual-spin trajectory correction projectile was built,to get the real-time control effect within the whole trajectory and evaluate the performance of different control algorithms and trajectory correction strategies.An actuator modeling method was proposed based on numerical simulation and experimental tests.The time-domain response characteristics under the step impact were recorded to conduct the transfer function analysis with the(inverse)Laplace transformation so that the dynamic electromagnetic torque model could be established.Based on experimental data in combination with the numerical simulation,the accurate aerodynamic and damping moment model was built,thus,the overall control response prediction model was established.It is shown by the roll control experiments in the wind tunnel that the established system model is able to predict the actual dynamic responding performance with a high degree of accuracy (less than 1.5%).The method for system modeling is proved to be feasible and provides an accurate and reliable analysis model for future research.
Measurement and Characterization of Electrostatic Elimination Effect of Needle Electrode Corona Discharge at Atmospheric Pressure
WANG Yan-ping, ZENG Dan, ZHANG Tong-lai, MIAO Jin-song
2018, 38(2): 190-195. doi:10.15918/j.tbit1001-0645.2018.02.014
Abstract(867) PDF(391)
Abstract:
In order to study the effect of high voltage electrostatic discharge elimination and the effectiveness of electrostatic protection,ionization test method was adopted to measure and analyze the influencing factors of needle electrode corona discharge at atmospheric pressure,such as voltage,frequency,power dissipation distance,electrode gap,balance voltage and so on. The result indicates that,the best power dissipation effect appears in high-voltage corona discharge within the frequency range of 1.8 kHz to 2 kHz;the DC and pulse corona discharge with high voltage has an obvious reverse charging effect,and the elimination effect increases with the increase of the voltage and the decrease of the distance.
A Soft Sensor Method Based on Just in Time Learning and Multi-Model Ensemble GPR
WANG Li, SUN Yu-mei, YANG Kai, LIU Xue-jie, CHEN Xiang-guang
2018, 38(2): 196-199,204. doi:10.15918/j.tbit1001-0645.2018.02.015
Abstract(869) PDF(439)
Abstract:
For some difficulties to realize real-time measurements of vital variables, a novel soft sensor based on the just in time learning (JITL) and ensemble learning Gaussian process regression (GPR) modeling was proposed. Firstly, different sub-blocks were created by principal component decomposition. Then a set of JITL-GPR models were developed based on various sub-blocks. Finally, some better results from JITL-GPR models were combined to adaptively obtain the prediction result. The proposed soft sensor was applied to the industrial rubber producing process. Result verifies the superiority of the proposed method.
Rubik's Cube as a Model of Quark Confinement Review and Improvement
WU He-ling
2018, 38(2): 200-204. doi:10.15918/j.tbit1001-0645.2018.02.016
Abstract(777) PDF(397)
Abstract:
It is one of multiple creative researches of the American mathematician,Solomon W.Golomb,that Rubik's cube is taken as a model of quark confinement.In this paper,reviewing its concept and analyzing its drawbacks,an improved solution was proposed.The torsion forms of the Rubik's cube block were extended form 3 kinds (0°、+120°、-120°) to 5 kinds (0°、+120°、+240°、-120°、-240°),strengthening the expression of the model so as to represent all types of the mesons and the baryons formed by the quark confinement.
A Doppler Wind Lidar Based on Image-Reject Homodyne Technology
CHEN Yu-bao, BU Zhi-chao, WANG Zhen-hui
2018, 38(2): 205-210. doi:10.15918/j.tbit1001-0645.2018.02.017
Abstract(1047) PDF(495)
Abstract:
At present, most of coherent Doppler lidar adopts heterodyne technique to obtain atmospheric velocity and direction in the radial direction of the radar. In this paper, a continuous all fiber Doppler wind lidar system was developed based on image-reject homodyne technology and using integrated 90° optical hybrid receiver. The IQ cross signal was got through the phase control of the local or receiving signal, and the radial wind was detected based on the image-reject homodyne technology. Compared with the lidar using heterodyne technique, this lidar presents some advantages, including higher signal to noise, stronger radar storage, greater speed range at the same ADC sample rate and so on. In the end, a lot of comparative experiments were implemented to verify the credibility of all fiber Doppler wind lidar. The results show that this system has high detection accuracy, the wind direction goes all the way with the anemometer, the wind speed bias is of -0.03 m/s and standard deviation is of 0.63 m/s.
Simulation Research on Coherent Wind Lidar Bandpass Sampling Method
ZHANG Yin-chao, LI Li-li, GUO Pan, CHEN Si-ying, CHEN He, RUI Xun-bao, JI Hong-zhu
2018, 38(2): 211-215. doi:10.15918/j.tbit1001-0645.2018.02.018
Abstract(1141) PDF(449)
Abstract:
A band-pass sampling method was introduced for the coherent wind radar system to solve the problems in the echo signal sampling, including the high carrier frequency, narrow bandwidth, especially several GHz echo signal of the spaceborne wind coherent radar, high sampling rate of acquisition card required with the traditional sampling method, the mutual constraints of sampling rate and resolution of acquisition card. In this paper, a simulation test was carried out, taking the acquisition data collected from 1.5μm all-fiber coherent Doppler lidar system as the input information to do Simulink filter and band-pass sampling. Results show that, compared with the low-pass sampling, the maximum difference of sight speed inversion is about 0.5 m/s when the change of detection distance is not large; furthermore, the time complexity of data processing is decreased, and its value is the ratio of bandpass sampling frequency and low pass sampling frequency. However, the ratio of signal to noise deteriorates, the value of which is about 1~3 dB.
Pharmacokinetic Study of Promethazine and Ephedrine Combination in Rats Under the Simulated Microgravity Condition
GAN Lin, ZHENG Zhi-fen, WANG Lu-jun, DENG Yu-lin, LI Yu-juan
2018, 38(2): 216-220. doi:10.15918/j.tbit1001-0645.2018.02.019
Abstract(745) PDF(388)
Abstract:
To provide basic research data for astronauts to take medicine reasonably and safely,some pharmacokinetic studies on promethazine and ephedrine were carried out in rats' plasma to obtain the pharmacokinetic parameters in different simulated weightlessness periods.A rat tail-suspension model was used to simulate weightlessness,and an HPLC-MS/MS method was developed to determine the promethazine and ephedrine quantification in rat plasma.The pharmacokinetic parameters in simulated weightless group show the differences between control and model groups,such as the area under the concentration-time curve (AUC0-t),peak plasma concentration (Cmax),elimination rate constantKeand half-life (T1/2).Different simulated weightlessness periods have a significant impact on the pharmacokinetic process of drugs in rats.

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