In this paper, the possibility of plastic deformation of rifle and gun barrels is studied through the numerical methods. When a rifle or tank gun is fired, the expansive deformation of the barrel can occur by the explosive pressure and the thermal effect. Using the ABAQUS program, the stresses and displacements are computed for the elastic and elastic-plastic material property, and the possibility of plasticity deformation is investigated. In conclusion, rifle and tank gun barrel the plastic deformation occurred in some parts of the barrel

Shock and vibration characteristics of a tractor-trailer type vehicle system with air suspension and air coupler running on a single bump road are investigated. The vehicle system is modelled and solved to two types of models, i.e. rigid-multi-body and flexible-multi-body model, by ADAMS and NASTRAN software. And the shock impulse is given by a single bump model on the road. When the analysis results of the rigid-multi-body model is compared with those of the flexible-multi-body model, it is revealed that the vibration and accelerations of the latter model are more repetitive and larger than the former.

Three dimensional, compressible, mass weighted averaging of Favre, Navier-Stokes system with k-$\varepsilon$ turbulence, is numerically discretized to compute three dimensional multiple jet interaction flow fields for a hybrid projectile containing three rocket motors in the ogive section. Numerical flow field computations have been made for angled nose jets and rockets at supersonic speed using multiblock structured grid. The jet conditions include very high jet to free stream pressure ratio and high temperature. It is shown that the strength of nozzle stagnation pressure affects the flow field near the side nozzle and the high stagnation pressure increases total amount of drag by a few percent. However, minor drag loss due to the pressure drag might be fully overcomed by an additional axial thrust. The results of present study can be applied for the design of future hybrid projectile.

A modified theoretical analysis of the ballistic perforation on the double and multi-layered armour plates using an upper bound method has been presented in this paper. A modified model based on the suggestion of the Awerbuch-bodner model has been adapted and extended into double and multi-layered armour plates when the plugging type of penetration has been occurred. The residual projectile speed, ballistic limit velocity and contact time during the penetration process have been derived from the equation of motion at each stage.

A torque control method of a switched reluctance motor for the position control of a tank gun is presented. One of the widely used torque control scheme, torque sharing function method, is investigated and a new torque sharing function method is proposed that extends the definition region of the conventional TSF to both the positive and negative torque production regions. By using this definition, all kinds of the control inputs that consider switching on/off angle control as well as the current profiling can be described. A parametrized representation of the current profiles is proposed by using a series of B-spline functions, which reduces memory requirement and enables additional controllers. Optimal determination of the TSFs are also investigated for various control objectives. Moreover, the comparison study of each objective is presented. Since this method generalizes all of the possible control input, the current and torque profiles obtained from the optimization are the most suitable control input that satisfy the objectives.

Organic brake materials are installed in the braking system of korean model combat vehicles. Since the binder resin is decomposed in high temperature region, it may possible to drop the friction force which makes the vehicle stop within the desired distance. This study analyses the braking performance of the brake materials in high temperature region by using the pin-on-disk type friction tester. It is observed radical drop of friction coefficients and rapid increase of wear amounts from the transition temperature. It is due to the formation of oxide layer on the friction surface.

An Adaptive Positive Position Feedback method is presented for controlling the roll of the supersonic smart projectile. The proposed strategy combines the attractive attributes of Positive Position Feedback(PPF) of Goh and Caughey, and Lyapunov stability theorem. The parameters of Adaptive-PFF controller are adjusted in an adaptive mauler in order to follow the performance of an optimal reference model. In this way, optimal damping and zero steady-state errors can be achieved even in the presence of uncertain or changing plant parameters. The performance obtained with the Adaptive-PPF algorithm is compared with conventional PPF control algorithm. The results obtained emphasize the potential of Adaptive-PPF algorithm as an efficient means for controlling plants such as supersonic flight systems with uncertainties in real time.

In Underwater Flight Vehicle depth control system, the followings must be required. Firstly, It need robust depth control performance which can get over parameter variation, modeling error and disturbance. Secondly, It need no oveshoot phenomenon to avoid colliding with ground surface and obstables. Thirdly, It need continuous control input to reduce the acoustic noise and propulsion energy consumption. Finally, It need effective interpolation method which can reduce the dependency of control parameters on speed. To solve these problems, we propose the Fuzzy-PID depth controller with the control parameter interpolators. Simulation results show the proposed control scheme has robust and accurate performance with continuous control input.

This paper presents an application of forced oscillation technique to measure pitch dynamic stability derivatives of a missile model in the low speed wind tunnel. The missile model is oscillated by D.C. electric servomotor with constant amplitudes and frequencies. Phase shift is determined as the difference of peak values between input and output signals from the dynamic stability balance installed at the center of gravity of the model. Stability derivatives were calculated by using phase shifts, amplitudes, forcing moments and input frequencies. Test results show the proper usage of the force oscillation technique with good damping effects.

The design of an automatic aircraft recognition system involves two parts. The first part is extraction of invariant features independent of scale, rotation and translation. The second part is determination of optimal decision procedures, which are needed in the classification process. In this research, we extracted invariant aircraft features regardless of size, rotation and translation using Fourier Descriptors and Zernike Moments and classified using neural networks.

A synthetic aperture radar (SAR) system can provide all-weather, day and night, superior imaging capability, and thus is very useful in surveillance for military applications. In this paper, a X-band spaceborne SAR system design concept is introduced with the key design parameters for mission and system requirements characterized by small satellite system. The SAR imaging mode design procedure is presented, and the standard imaging mode design results are analyzed as an example. In line with the given mission and system requirements, the X-band SAR payload and ground reception/processing subsystems are designed and presented with the key design results. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.

A practical method is proposed to improve hit probability of the digital gun fire control system, when the measured rate of the tracking sensor becomes biased under some operational situation. For ground moving target it is shown that the well-known Kalman filter which uses position measurement only can be optimally used to eliminate the rate bias error. On the other hand, for 3D moving aircraft we present a new algorithm which incorporate FIR-type filter, which uses position and rate measurement at the same time, and the fixed-lag smoother using position measurement only, and show that it has the optimal performance in terms of both estimation accuracy and response time.

A design of CPS attitude determination system is described in this paper. The designed system is a low cost high precision 24 channel single frequency GPS(Global Positioning System) receiver which provides a precise absolute heading and pitch (or roll) as well as a position. It uses commercial chip-set and consists of two RF parts, two signal-tracking parts, a processor, memory parts and I/Os. In order to determine precise attitude, accurate carrier phase measurements and an efficient integer ambiguity resolution method are required. To meet these requirements, a PLL (Phase Locked Loops) is designed, and an algorithm called ARCE (Ambiguity Resolution with Constraint Equation) is adopted. The hardware and software structure of the system will be described, and the performance evaluated under various conditions will be presented. The test results will promise that more reliable navigation system be possible because the system provides all navigational information such as position, velocity, time and attitude.

This paper presents a fault detection and isolation(FDI) method based on Generalized Likelihood Ratio(GLR) test for the tightly coupled SDINS/CPS system. The GLR test is known to have the capability of detecting an assumed change while estimating its occurrence time and magnitude, and isolating the changing part. Once a fault is detected even if we don't know if the fault occurrs at either INS or GPS, multi-hypothesized GLR scheme performs the fault isolation between INS and GPS, and find which satellite malfunctions. However, in the INS faulty case, it turned out to fail to accomodate the fault isolation between accelerometer and gyroscope due to the coupling effects and a poor observability of the system. Hence, to isolate the INS fault, it needs to change the attitude of the vehicle resulting in enhancing the degree of observability.

This paper presents results from a computer-aided systems engineering application to system development projects. RDD-100 version of ALC Inc. was used in this work. The framework adopted in the study takes a unified approach to the system design and the process management associated with it, thereby coherent and full traceability between them is maintained. Conventional system engineering process supported by the tool is adopted in the system design. On the other hand, the same tool is also used to the systems engineering management to get full traceability between system design data and engineering management data. It is greatly helpful in managing many sub-contractors in the sense that the traceability can help identify the sub-project responsibility as well as the objectives of the project in coordination with interface requirements. We conclude with the advantage and limits of our unified approach.

This paper describes modeling and simulation of automotive forward collision warning and avoidance system using CASE(Computer-Aided Systems Engineering) tool. The system is composed or many sensors, a controller, warning devices, brakes and etc. The system was modeled by one activity chart, fourteen state charts and one module chart. Rear-end collision scenarios was generated by Simulink and used to support Stalemate model. The resulting model was used to evaluate the correctness of function and behavior of the system. A simulator for the system has been designed and used to validate the model under realistic operating conditions in the laboratory. To model and simulate the system's functionality and behavior brings clarity to system design early in the system development.

As the 21st century signifies an information-oriented society, the computer integration takes place in all walks of human presence. Needs for computer and network-integrated automation present new challenges in military as well as commercial facility systems engineering. Since the first intelligent building appeared in USA in 1984, it gradually became an essential capability for the building industry requirement these days. Intelligent Building System(IBS) is evolving to be very complex because there are many subsystems such as telecommunication(TC), office automation(OA), building automation(BA), security, construction environments, etc. During the planing phase of IBS development, therefore, a disciplined systems engineering must be performed to analyze stake- holder's requirements to build an optimized system while minimizing trial-and-error expenses and risks. This paper presents a conceptual design of BAS applying systems engineering methods. The contribution of this study includes the development of IBS subsystem specification for building automation subsystem, which is a part of IBS, using the methodology of requirement analysis, functional analysis, synthesis, and verification. A computer-aided systems engineering s/w, RDD-100, was used to improve the system design efficiency and to promote the product design knowledge management for reuse in later design programs.

Multi-disciplinary optimization design concept can provide a solution to many engineering problems. In the field of structural analysis, much development of size or topology optimization has been achieved in the application of research. This paper demonstrates an optimum design of a multi-layer cylindrical tube which behaves thermoelastically. A multi-layer cylindrical tube that has several different material properties at each layer is optimized within allowable stress and temperature range when mechanical and thermal loads are applied simultaneously. When thermal loads are applied to a multi-layer tube, stress phenomena become complicated due to each layer's thermal expansion and the layer thicknesses. Factors like temperature; stress; and material thermal thicknesses of each tube layer are very difficult undertaking. To analyze these problems using an efficient and precise method, the optimization theories are adopted to perform thermoelastic finite element analysis.

This paper deals with the improvement of defense codification system for the items of defense supplies. We review other country's codification systems, their concept and trend of the systems for development, and then apply the ideas to our defense codification system. The proposal for improvement of defense codification system consists of three parts. The first one is the aspect of policy, the second one is the aspect of organization, and the last one is the aspect of operation. This paper will be contributed to the development of national codification system, and defense logistics management.

The waste ammunitions have been accumulated in excessive amounts these days. This study focused on the problems related to the method of ammunition disposal which leads the explosion inside the enclosure structure and controls the effects of detonation. This study enables us to design a new type of explosive disposal facilities that would fit to our environments. And this study gives us the prototype design of the explosive disposal structure that are explored in this research and will give us a chance to develop a new type structure that have not been devised by Army, and also will be applicable to construct a civilian explosive disposal structure located in airports, harbors, and public facilities.

An experimental study was performed to investigate the effect of surface temperature mismatch on measurements of skin friction using a plug-type skin friction gage mounted on the side wall of a supersonic wind tunnel. The freestream Mach number was 2.4 and Reynolds number per meter was $5.25 {\times}10^7$ with total pressure of 50 psi and total temperature of 275K. Temperature mismatch between the gage surface and surrounding wall surface was generated by hot water injection using the active temperature control system. Results of the tests showed that the temperature mismatch made sizable effects on the measurements of skin friction.

Plastic bonded explosive(PBX) is mainly composed of the nitramine explosives, RDX, HMX, and polymer binders. When the adhesion between nitramine crystals and binder is not particularly strong and can be failed under stress, dewetting occurs rather suddenly and this leads to a significant drop in tensile strength of explosives. Mechnical property of plastic bonded explosive depends on the surface characteristics of filler and binder. In order to design for better adhesion, an understanding of the surface properties of explosive and binder is essential. In this study, 2 kinds of RDX and 4 kinds of ethylene vinyl acetate copolymers are selected, since they are widely used in many plastic bonded explosives. The technical objective of this investigation is to calculate for the surface free energy of RDX and EVA using theory of Fowkes, van Oss, Neumann approaches and Kaelble equation and to predict the interaction between filler and binder from their surface free energies.

This paper describes a simulation of secondary motion of piston assemblies using PISDYN by Ricardo. Motions of the piston, pin, rod and skirt are separately calculated, by integrating equations of motion for individual components and dynamic degrees of freedom. The effects of engine speed at full load and pin offsets on the piston assembly secondary motions, forces and friction were investigated in parametric study for 4-cylinder gasoline engine. Results show that lateral displacement and friction loss of the piston increase as a function of engine speed. The lateral motion of the piston is affected by the change in pin offset. The minimum friction loss for the condition of 4800rpm WOT occurs at a pin offset of 1.6mm.

Thermal gradient chemical vapor infiltration (TG-CVI) process, which is one of the CVI techniques to densify a porous fiber preform, requires for a heater to have uniform surface temperature distribution. Thus, it is essential to design the shape of the heater and to predict the temperature distribution when the heater has a profile which is not a simple cylinder. In this study, an analytical method has been used to design the inner profile of a conical heater showing uniform temperature distribution, if its outer shape is specified. Temperature distribution on the heater surface has been calculated with the finite difference method and compared with the experimental results. When a heater had a combined profile with a large cone and a small cylinder, temperature was higher in the cylindrical part. To reduce the temperature difference between these areas, a hole-machining method has been proposed including other possible ones. A shape design and optimization program has been made to improve the temperature uniformity of the TG-CVI heater better than that designed with the analytical method.

본 논문에서는 soot을 배출하는 층류 확산 화염에 대한 음향 가진(acoustic excitation) 효과에 대해 연구하였다. 최근의 연구결과는 soot 배출 화염에 음향 가진을 작용시키면 radiation은 증가하고 soot 배출은 감소한다는 사실을 밝혀주었다. 음향 속도(acoustic velocity)는 음향 압력(acoustic pressure)과 900 상(phase) 차이가 있기 때문에 acoustic driver를 장착한 유리 튜브 내부의 축방향으로 soot을 배출하는 아세틸렌 확산 화염을 이동시킴으로서 soot 배출 감소에 대한 음향 속도와 음향 압력의 상대적인 중요도를 밝혀낼 수 있다. Soot을 배출하는 아세틸렌 화염에 soot 배출이 멈출 때까지 음향 가진을 작용시키고 유리 튜브 안의 최대 압력 위치에서 음향 압력을 측정하며, 화염 위치의 음향 속도와 음향압력은 운동량 방정식과 파동 방정식을 통해 계산된다. 실험 결과 음향 속도가 최대이고 음향 압력이 최소인 위치에서 보다 음향 속도가 최소이고 음향 압력이 최대인 위치에서 훨씬 더 큰 acoustic power가 필요함을 보여주었다. Soot 배출을 멈추는데 필요한 음향 속도의 크기는 유리 튜브의 축방향에 대해 거의 일정한 반면 음향 압력의 크기는 상당한 변화가 있었다. 이러한 결과는 Soot 배출의 감소가 주로 음향 속도에 의한 것임을 강하게 시사한다고 할 수 있다. 또한 연료의 유량이 증가함에 따라 soot 배출을 억제하는데 필요한 acoustic power도 증가한다는 사실을 확인 할 수 있었다.