No208 Research Institute Of China Ordnance Industries

Beijing, China

No208 Research Institute Of China Ordnance Industries

Beijing, China
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Qiao Z.-P.,No208 Research Institute Of China Ordnance Industries | Huang X.-Y.,63856 Unit of PLA
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2017

In the conventional analysis and numerical calculation of the temperature field of gun barrel, the effects of special structures such as barrel riing, radiating ribs or fins, and the heat conduction between gun barrel and its adjacent parts were neglected, which difference of inner and outer boundary conditions for the calculation of gun barrel field. To this problem, two correction coefficients were introduced to modify the composite heat transfer coefficients between the propellant gas and inner wall and between the gun barrel outer surface and the ambient air. The two formulae of correction coefficients varying with the distance away from the gun muzzle were obtained by fitting with non-linear least square method. The test results of the temperature field of the gun barrel outer surface by thermal infrared imager were compared to the numerical calculation results by original and modified models, which demonstrated that the modified model was more accurate and reliable. The further analysis and numerical calculations of gun barrel temperature were conducted with the modified model, and the axial temperature distributions of both inner wall and the outer surface of gun barrel for some different fired rounds were obtained. The research results had great importance for the further studies of gun barrel erosion mechanism and provided the reliable theory basis for the structure design and the life prediction of gun barrel. © 2017, Science Press. All right reserved.


Zeng X.,Nanjing University of Science and Technology | Zhou K.,Nanjing University of Science and Technology | He L.,Nanjing University of Science and Technology | Gong P.,Nanjing University of Science and Technology | And 2 more authors.
Advanced Materials Research | Year: 2012

To investigate the wounding effects in human on the basis of the similarity theory, by taking the temporary cavity as the research object, through the analysis on the forming of cavity and its physical process, main influencing factors effecting temporary cavity are obtained, which can provide a good theoretical basis for similarity research in wounding ballistics in the future, and the killing effect of the high speed steel ball is more deeply described. © (2012) Trans Tech Publications, Switzerland.


Lu Y.,Nanjing University of Science and Technology | Zhou K.-D.,Nanjing University of Science and Technology | He L.,Nanjing University of Science and Technology | Feng G.-T.,Nanjing University of Science and Technology | Li J.-S.,No208 Research Institute Of China Ordnance Industries
Dandao Xuebao/Journal of Ballistics | Year: 2014

Aiming at the complex structure of barrel bore and projectile and the highly nonlinear engraving-process, the projectile bottom pressure during the engraving-process was sholved, and the high-precision finite-element-models of barrel and projectile were established by multi-softwares. The projectile engraving process was simulated. The space-time evolution of suffered stress and deformation in the engraving process of projectile was analyzed, and the formation process of rifling indentation on projectile was demonstrated. The simulated results of the variation regularity of engraving resistance of projectile were obtained. By comparing the different coefficients of determination of different fitting formula for engraving resistance, the optimal fitting formulae of engraving resistance of projectile was obtained. The results offer theoretical reference for the study of the issues of initial interior ballistics and the design of barrel bore.


Wen Y.K.,Nanjing University of Science and Technology | Xu C.,Nanjing University of Science and Technology | Dong X.H.,Nanjing University of Science and Technology | Wang S.,No208 Research Institute Of China Ordnance Industries
Advanced Materials Research | Year: 2013

Ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced plastic (UFRP) is an integral part of hard body armor. The intensive study on the material characterization of UFRP can help to understanding the bulletproof mechanism and behind-armor blunt trauma (BABT) well, and thus improve the performance of body armor. The research presented in this paper represents an effort to characterize the properties of UFRP under quasi-static and ballistic loading. The tensile behavior along the fiber direction and through thickness compressive behavior were obtained using an universal material testing machine. Experiments show that the tensile strength and compressive strength of UFRP are approximately 500MPa and 650MPa, respectively. The through thickness shear strength of UFRP was also obtained according to the punch-shear testing, and a set of special clamp was used to clamp the samples. The composite has been found to have a low shear strength. The UFRP was impacted by a 4.8mm diameter spherical fragment with velocity 694m/s~920m/s, to study the ballistic performance. And the height and radius of the deformed conical region on the back face of UFRP were captured using high-speed photography technique. Results show the maximum transient height of the cone is about 3 to 4 times greater than the final height of the cone, and the radius of the cone reaches to 59±7.4mm. The ballistic limit of the 11mm thick UFRP is approximately 800m/s. © (2013) Trans Tech Publications, Switzerland.


Wu Q.-J.,Nanjing University of Science and Technology | Zhou K.-D.,Nanjing University of Science and Technology | He L.,Nanjing University of Science and Technology | Zeng X.,Nanjing University of Science and Technology | Li J.-S.,No208 Research Institute Of China Ordnance Industries
Nanjing Li Gong Daxue Xuebao/Journal of Nanjing University of Science and Technology | Year: 2011

To research the damage mechanism of the composite thick-wall cylinder, based on the continuum damage mechanics theory, an energy-based stiffness degradation method is proposed to predict the progressive failure properties of a steel-carbon fiber/polyimide composite thick-wall cylinder. Three failure modes of carbon fiber/polyimide composites, including fiber breakage, matrix cracking and fiber/matrix interface shear failure are considered in the model. A three-dimensional finite element technique including the multiframe restart analysis and the arc-length algorithm is employed to conduct the progressive failure analysis. The result shows that: matrix cracks first, then the fiber breakage causes final failure of the whole structure before interface shear failure and liner damage; there is no shear failure or lining failure in this process; the strength of fiber decides the strength of composite thick-wall cylinder.


Wen Y.K.,Nanjing University of Science and Technology | Xu C.,Nanjing University of Science and Technology | Chen A.J.,Nanjing University of Science and Technology | Wang S.,No208 Research Institute Of China Ordnance Industries
Advanced Materials Research | Year: 2013

A series of ballistic tests were performed to investigate the bulletproof performance of UHMWPE composites. The temporal evolution of the UHMWPE composite plate back-face bulge height and diameter were captured by high-speed photography. The experiments show the composite plate were perforated when the impact velocity greater than 880m/s. The maximum bulge height and diameter can reach to 3.63-8.23mm and 37-64.5mm at the experimental velocity range, respectively. After that, the numerical model was built with composite material model MAT59 in LS-DYNA and stress based contact failure between plies were adopted to model the delamination mechanism. The number of plies of numerical model shows a strong dependency on the numerical results. Comparisons between numerical predictions and experimental results in terms of bulge height and diameter are presented and discussed. The maximum bulge diameter is good agreement with experiment, but the computational results under predict the maximum bulge height. The computational analysis show the damage development of the plate penetration by the projectile is shearing dominated at first, then the plate undergoes delamination and stretching in the later part of the impact process. The von mises stress at front and back face of the plate were also studied. © (2013) Trans Tech Publications, Switzerland.


PubMed | No208 Research Institute Of China Ordnance Industries, Nanjing University of Science and Technology and Virginia Polytechnic Institute and State University
Type: | Journal: Journal of the mechanical behavior of biomedical materials | Year: 2016

The penetration of a rifle bullet into a block of ballistic gelatin is experimentally and computationally studied for enhancing our understanding of the damage caused to human soft tissues. The gelatin is modeled as an isotropic and homogeneous elastic-plastic linearly strain-hardening material that obeys a polynomial equation of state. Effects of numerical uncertainties on penetration characteristics are found by repeating simulations with minute variations in the impact speed and the angle of attack. The temporary cavity formed in the gelatin and seen in pictures taken by two high speed cameras is found to compare well with the computed one. The computed time histories of the hydrostatic pressure at points situated 60 mm above the line of impact are found to have two peaks, one due to the bullet impact and the other due to the bullet tumbling. Contours of the von Mises stress and of the effective plastic strain in the gelatin block imply that a very small region adjacent to the cavity surface is plastically deformed. The angle of attack is found to noticeably affect the penetration depth at the instant of the bullet tumbling through 90.


Li X.J.,No208 Research Institute Of China Ordnance Industries | Mao X.W.,No208 Research Institute Of China Ordnance Industries | He L.,No208 Research Institute Of China Ordnance Industries | Wang X.R.,No208 Research Institute Of China Ordnance Industries
Applied Mechanics and Materials | Year: 2014

Lower Extremity of Power Assist Robot could add the strength and endurance of robotics to a human's innate adaptability to help the wearer transport heavy loads over rough and unpredictable terrain. Dynamics Analysis and Control Strategy Simulation are the important aspects for the researching of the robot. The dynamics equation of Lower Extremity of Power Assist Robot is built by the Lagrange equation. The relationship between the active joint torque of the robot and plantar pressure is established, which support the theoretical foundation for the dynamic control to achieve the desired effect. Base on the analysis of working environment and the mechanical environment of the robot, the force-location control theory is used to control robot, which is simulated based on Simulink blocks of MATLAB to get a better tracking performance. © (2014) Trans Tech Publications, Switzerland.


Tian C.,No208 Research Institute Of China Ordnance Industries | Wang J.,No208 Research Institute Of China Ordnance Industries | Yin Z.,No208 Research Institute Of China Ordnance Industries | Yu G.,No208 Research Institute Of China Ordnance Industries
Chinese Control Conference, CCC | Year: 2016

Quadrotor is a kind of rotor unmanned aerial vehicle (RUAV), which has the feature of natural nonlinearity and strong coupling. In addition, it has complex aerodynamic characteristics such as side wind disturbance, etc. Due to these unique properties, there exist a lot of difficult problems in the control of quadrotor. In this paper, precise dynamics model is established under the consideration of gyroscopic moment and air disturbance. The model is then constructed to a convenient form, which is suitable for the integral backstepping method based controller design. Finally, the whole control system is divided into two parts, which is referred as double loop control structure. The inner loop is about the motion stabilization while the outer loop is about the position stabilization. Then, the motion controller and position controller are designed via adopting the Integral backstepping method. Finally, simulation results of tracking the constant speed signal, tracking the helix signal, and hovering with air disturbance are implemented respectively. The simulation results show that the whole system has perfect tracking effect and strong capability suppressing air disturbance. Thus, the correctness and effectiveness of the controller design method in this paper are verified. © 2016 TCCT.


Zuo H.,No208 Research Institute Of China Ordnance Industries | Sha J.,No208 Research Institute Of China Ordnance Industries | Han R.,No208 Research Institute Of China Ordnance Industries | Liu Y.,No208 Research Institute Of China Ordnance Industries
Advanced Materials Research | Year: 2013

In order to simulate the rupture process of Cartridge Case, material failure constitutive model is researched. Johnson-Cook plasticity model is given as an analytical function of equivalent plastic strain, strain rate, stress triaxiality. Johnson-Cook plasticity model and Johnson-Cook Damage initiation criterion are used to describe the plastic deformation and fracture of case for the pressure of power gas. Using the implementation of this stress-displacement and characteristic length, problem of the relationship between fracture energy and the characteristic length in finite element model is solved. Finally, the simulated model which includes barrel, case, bolt and locking rigidity spring is built. Comparing the fracture shape and position in simulated test and physical experiment, the results are very similar. It proves that the rupture process of Cartridge Case can be simulated by the constitutive model which is introduced in this paper. © (2013) Trans Tech Publications, Switzerland.

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