Papers by Author: Shun Shan Feng

Abstract: Polyurethane foam has the properties of energy absorption and mitigating the impact, it has been used in internal protection head cap of cylindrical objects as cushion material, its theory and simulation has been widely discussed by the domestic and foreign scholars, but little experimental research is involved. In this paper, a dynamic loading water-entry impact experiment was designed for polyurethane foam plastics with different densities. In addition, ANSYS/LS-DYNA finite element analysis software was used to simulate water-entry process of cushion materials with different densities. The experimental and simulation results show that the 0.18 g/cm³ polyurethane material can effectively protect the cylindrical head, reduce the stress and have a good cushion effect on it.

Abstract: For the short-range defensive weapons, extracting the acoustic characteristic of attacking aircraft at low altitude is an effective way to detect and recognize the target. The signal characteristics of radiated noise of the typical vehicle propulsion system are analyzed, and thus the signal models for propulsion system noise and for passive acoustic early-warning system are given. Finally, the analysis result of the measured aircraft noise validates the feasibility of the signal model.

Abstract: The degree of protection/damage of the target is an important basis for the target structure design. In the military field, the target can be equivalent to a target metal plate with the certain thickness. The degree of protection can be divided through the effect of target plate under blast loads. Considering the reflected parameters, the reflected pressure-impulse criterion can be used to assess the damage caused by the blast. Through the combination of theoretical analysis and numerical simulation, the target plate’s pressure-impulse diagrams of different degrees are obtained. The results of the experiments and simulations are found in good agreement, which validates the numerical model.

Abstract: The impact explosive temperature of reactive material is not only an important indicator to measure the ability of explosive reaction, but also a required parameter to carry out thermo-chemical calculation. So there is important practical significance to study the impact explosive temperature effect of reactive material. Based on one-dimensional shock wave, thermodynamics and physical chemistry theory, mathematical analysis model of impact explosive temperature vs. mass ratio of the reactive material is established. By MATLAB programming, the curve of impact explosive temperature vs. the mass ratio of PTFE/Al reactive material is received, which can be used to analyze variations. Fitting function equations is obtained by MATLAB CFTOOL. At last, the contrast of original calculation curve with fitting curve validates the appropriateness of the fitting function equations. From the view of impact explosive temperature effect, we suggest that the established model and research method can be applied to the dynamic properties research of other reactive material.

Abstract: According to mathematical model of MEMS, In case attitude updating period sampling period are the same , single-sample, two-sample and three-sample algorithm are studied based on rotation vector method, and the simulation and comparative analysis are proceed. In the same sample rate cases, the results show that calculating precision of two-sample and three-sample changes with growing attitude updating cycle. Before turntable test or practical application, all samples should be simulated respectively. Choose the best method for attitude solving and provides the basis for the engineering.

Abstract: The blockage damage to the movable target on the ground with the mode of deterring is an important aspect of research about the fragment warhead. The analytic method of damage power about the blockage warhead cluster with the three blockage districts, including districts of dense damage in close distance, sparse damage in middle distance and deterrence damage in wide distance, was raised to do the research on the designing method of blockage damage warhead and the evaluation of blockage damage effect. The lying and standing static effectiveness test of the blockage warhead were designed based on the special blockage damage character. The designing method of the blockage damage warhead and the analytic method of blockage power characteristic were proved to be scientific, and the researching is significant in project application.

Abstract: Small cylindrical object navigating near free-surface is subject to wave disturbance. Wave disturbance can dramatically influence the depth control of the near-surface navigating object. A self-regulating fuzzy depth control method is proposed to keep the small cylindrical object navigate at the expected depth under free-surface disturbance. The near-surface dynamic model of the cylindrical object is presented and the fuzzy depth control method is modeled. The results obtained by a series of hardware-in-loop simulations demonstrate that the self-tuning fuzzy depth control method is valid to keep the small cylindrical object navigate steadily in the expected depth under free-surface disturbances.

Abstract: Three-stage model of normal penetration of rigid projectile into aluminum plate is developed base on cavity expansion theory (plate thickness is smaller than projectile nose length). Correction method of the models is proposed and predicted results have good agreement with experimental data. The influence of target’s yield stress, target material parameter, sliding friction coefficient and projectile nose shape to penetration process is analyzed through numerical solution. It provides an effective mechanical analysis model for research of projectile impact resistance method to aluminum protective structure.

Abstract: Based on the cavity expansion theory, an analysis model of normal penetration of slender nose projectile into armor targets was established, and the variation relation curve of penetration depth and initial velocity when initial velocity is below ballistic limit was obtained. By carrying out ballistic impact test using 85mm smoothbore gun, various projectile nose shapes and armor target thickness and their effect on damage were considered. The research results have indicated that the damage of target is mainly ductile reaming and the shape of crater is almost the same as the projectile nose embedded in the target. Within a relatively low velocity range, nose shape has a greater influence on penetration depth. In contrast, within a relatively high velocity range, the target thickness has a greater influence on penetration depth. It can provide theoretical basis for the design of projectile noses and analysis of anti-penetration performance of armor targets.

Abstract: Partial penetration means partial body of projectile is in target, the other out of target. Analysis model of slender nose projectile partial penetrates steel target is proposed base on cavity expansion theory (plate thickness is smaller than projectile nose length), and the variation relation of penetration depth with initial velocity is concluded when projectile partially penetrates steel target. Penetration tests are carried out on hard projectile penetrates steel target, and the predicted results of penetration depth have good agreement with experimental results.