Time filter

Source Type

Wang W.-L.,Yantai Naval Aeronautical and Astronautical University | Li Y.-S.,Yantai Naval Aeronautical and Astronautical University | Tian C.-Y.,Chongqing Hongyu Precision Industrial Co.
Huozhayao Xuebao/Chinese Journal of Explosives and Propellants | Year: 2011

In order to verify the feasibility of installing annular shaped charge on the front of active missile s warhead, the numerical simulation is used to optimize the design of annular cutter, and the range cut test is used to preliminary investigate the damage effect. The results show that the cut effect on thick target is significant for the optimized annular cutter, and the cut effect is strong for 40mm targets at 30° attack angle. The conclusion provides reference for the newly tandem warhead design.

Yang L.,Beijing Institute of Technology | Nie J.,Beijing Institute of Technology | Jiao Q.,Beijing Institute of Technology | Li J.,Beijing Institute of Technology | Ren M.,Chongqing Hongyu Precision Industrial Co.
IEEE Transactions on Plasma Science | Year: 2015

Based on the fact that the double-deck rail demonstrates excellent performance in preventing rails melting and gouging during electromagnetic launch tests, theory and simulation research studies were carried out on the lateral vibration of the double-deck rail and contact properties between the armature and the rail in this paper. We deduced the lateral vibration contact equations of the double-deck rail by simplifying the electromagnetic rail launcher as Bernoulli-Euler model based on the elastic foundation. A finite-element code was used to help us model the launch progress. The influence of the double-deck rail scheme has been analyzed. Both the characteristics of the contact surface between the rail and the armature and the displacement of the rail were considered. The results show that the double-deck rail can inhibit the propagation of bending waves and efficiently reduce rail gouging. Besides, the connection method of the two decks has much influence on this effect. © 2015 IEEE.

Wang J.,Beijing Institute of Technology | Wu H.-J.,Beijing Institute of Technology | Pi A.-G.,Beijing Institute of Technology | Huang F.-L.,Beijing Institute of Technology | Liu Z.-W.,Chongqing Hongyu Precision Industrial Co.
Key Engineering Materials | Year: 2016

Long rod has strong ability of penetrating into targets with high velocity because of the big ratio of L/D. In the process of the penetration, the resistance of target is so big that the deformation of the head of the projectile is severe. There are many factors influence the process, which make it difficult to get analytic solutions. In this paper, we propose a simplified calculation method which considering engineering strain of the head of projectile. And the rigid-plastic model was used to describe the constitutive model of projectiles. The relationship between the engineering strain of the mushroom area and velocity was analyzed, which is exponential. Then, combined with cavity expansion theory, the calculation results about the DOP are in good agreements with the experimental results. At last, there are numerical simulations about the relative experiments, and the results obtained from numerical simulations show the deformation of the projectile and the depth of the penetration, which are in good agreement with the theoretical calculation and experiments. © 2016 Trans Tech Publications, Switzerland.

Zhang S.,Beijing Institute of Technology | Wu H.-J.,Beijing Institute of Technology | Tan Z.-J.,Chongqing Hongyu Precision Industrial Co. | Huang F.-L.,Beijing Institute of Technology
Key Engineering Materials | Year: 2016

This paper aims to establish a model that considers the penetration resistance caused by the constraint effects of steel reinforcements on concrete. Firstly, based on the experiment phenomena that reinforcements increase the toughness and tensile strength of concretes, the fitting relational expression between toughness of reinforced concrete and ratio of reinforcement was used to improve the Griffith yield criterion for reinforced concrete. Then, the dynamic spherical cavity expansion analysis was developed using the improved Griffith yield criterion as constitutive model and the dilation equation as equation of state, and the response regions were consisted of six distinct zones: cavity, compaction zone, dilation zone, radially cracked zone, elastic zone and undisturbed zone. This dynamic analysis considered the compression and dilation of concretes at the same time and was applicable to the penetration problem of reinforced concrete target. At last, based on the theoretical model of this paper, the experiments of projectiles with different weights penetrating into reinforced concrete targets with different reinforcement ratios were calculated using penetration analysis method of rigid projectiles. The comparison results showed that the theoretical analysis model of this paper can be used to predict the depth of penetration and other physical parameters such as velocity and deceleration with certain rationality. © 2016 Trans Tech Publications, Switzerland.

Zhang S.,Beijing Institute of Technology | Wu H.-J.,Beijing Institute of Technology | Pi A.-G.,Beijing Institute of Technology | Chen W.,Chongqing Hongyu Precision Industrial Co. | Huang F.-L.,Beijing Institute of Technology
Proceedings - 29th International Symposium on Ballistics, BALLISTICS 2016 | Year: 2016

The generalized smoothed particle hydrodynamics (GPH) method, an upgrade of smoothed particle hydrodynamics (SPH) method, can reflect the real state of failure materials more accurately by changing their volumes and shapes, not just by changing particle volume like SPH method. This paper briefly introduced the GPH method and the Impa3D program, and presented a numerical study on the simulation of high velocity projectile penetrating into concrete using FEM-GPH adaptive coupling algorithm. The simulation results indicate that the FEM-GPH adaptive coupling algorithm transform failure FEM elements into GPH particles which can continue to participate in the computation. Thus, it is a better way in showing the mass erosion and deformation of projectile nose as well as the generation and extension of target crack compared to FEM with erosion algorithm, although it doesn't compute efficiently.

Wang J.B.,Beijing Institute of Technology | Wang J.B.,Chongqing Hongyu Precision Industrial Co. | Zhang Q.M.,Beijing Institute of Technology | Xu G.Y.,Chongqing University of Technology | Feng C.L.,Chongqing Hongyu Precision Industrial Co.
Advanced Materials Research | Year: 2014

It was found from the experiment that the high temperature caused by target impact led to projectile austenite phase transformation. Based on this finding, a phase transformation model was established and verified by experiments, which proved the model had a relatively high calculation precision. Then, the model was used for numerical simulation. The result showed that the phase transformation zone was at the projectile head surface and the area increased as the impact velocity increased. The critical impact velocity which would cause phase transformation and affect projectile performance was around 700m/s. © (2014) Trans Tech Publications, Switzerland.

Xu G.Y.,Chongqing University of Technology | Xu G.Y.,China University of Petroleum - Beijing | Wang J.B.,Chongqing Hongyu Precision Industrial CO. | Guo L.P.,Northeast Petroleum University | Sun G.G.,China University of Petroleum - Beijing
Advanced Materials Research | Year: 2014

TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass. © (2014) Trans Tech Publications, Switzerland.

Xu G.,Chongqing University of Technology | Wang J.,Chongqing Hongyu Precision Industrial Co.
Chemosphere | Year: 2014

This work investigated degradation of decabromodiphenyl ether (BDE-209) by Phlebia lindtneri under the influence of glucose and heavy metals (Cd(2+), Cu(2+) or Pb(2+)). The results showed that adding glucose could markedly promote BDE-209 biodegradation. In the absence of heavy metals, 77.3% BDE-209 was degraded within 30d when dealing with 20mgL(-1) BDE-209. BDE-209 degradation was stimulated at low concentrations of Cu and Pb, whereas inhibited at higher levels of metals. The culture pH tended to decrease with time. Adding lower concentrations of Cu (5.0mgL(-1)) enhanced laccase activity. No stimulatory effect was observed on laccase activity in the presence of Cd or Pb. Ecotoxicity in the culture significantly increased at the late stage of the experiment. Bromine ions were released and the debromination rate of BDE-209 was much lower than its degradation rate. The fungus could degrade BDE-209 through debromination, hydroxylation, and ring-opening reactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

She Z.,Hunan University | She Z.,Researches Power Electronic and Electrified Transmission | Liu J.,Hunan University | Zhang B.,Chongqing Hongyu Precision Industrial Co. | And 2 more authors.
Proceedings of 2010 International Conference on Intelligent Control and Information Processing, ICICIP 2010 | Year: 2010

Soft starters have been widely used in fans and pumps drives. It is difficult to start high-power heavy-duty induction motor for traditional soft starter. To solve the problem of soft starter for large power and heavy load in conventional soft starters, the soft starter based the theory of discrete frequency is studied in this paper, which can make motor start with high torque and little current. Using discrete frequency makes the start frequency of motor from 5.25Hz to 50Hz step by step, which can make start torque larger. This paper presents a method of the calculation of optimal triggering angle which can make the torque be the biggest and positive was produced. The simulation waveform by MATLAB is similar to the real waveform by experiment. Control hardware circuit is simple and dependable. The experiment of the high torque soft starter which has a DSP as microcomputer is completed. The experimental results show that discrete frequency soft starter can start motor smoothly with high starting torque and small starting current. The advantages of discrete frequency soft starting proposed in this paper are stable start process, simple structure, low starting current and high starting torque. The result of load test is identical that conforms the theory is correct and valid. © 2010 IEEE.

Li W.,Chongqing Hongyu Precision Industrial Co. | Feng C.,Chongqing Hongyu Precision Industrial Co. | He Y.,Nanjing University of Science and Technology | Wang J.,Chongqing Hongyu Precision Industrial Co. | Chen C.,Nanjing University of Science and Technology
Advanced Materials Research | Year: 2012

In order to study the influence of projectile structure on the trajectory stability of oblique penetration concrete, this paper designs five kinds of projectile structure including cylinder, stern, tapered tail, cone with 4° and 7°. By using the LS-DYNA simulation software, the process of five kinds of projectile structure penetration into concrete is studied. Through the analysis of projectile axial resistance, projectile lateral displacement, deflection angle of penetration process and trajectory, it is obtained that the terminal trajectory stability of different projectile structures, from optimal to worse, they are tapered tail, cone, stern and cylinder. It also obtains that projectile lateral displacement and deflection angle of penetration process gradually increase with the increase of oblique angle. © (2012) Trans Tech Publications.

Loading Chongqing Hongyu Precision Industrial CO. collaborators
Loading Chongqing Hongyu Precision Industrial CO. collaborators