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Winya N.,Defence Technology Institute Public Organization | Winya N.,Kasetsart University | Hansupalak N.,Kasetsart University
MATEC Web of Conferences | Year: 2016

This study focused on improving the ablation properties and mechanical properties of natural rubber (NR)/ethylene propylene diene monomer (EPDM) blends by using two different commercial fillers: sepiolite and silica. The results showed that sepiolite and silica similarly improved both properties in the loading range of interest (0-12.5 phr). However, sepiolite was superior than silica as using less loading to acheive comparable mechanical and thermal properties. The optimum loading of sepiolite was 5 phr, while that of silica was 10 phr. For both filler systems, the minimum ablation rate found was approximately 0.17 mm/s, and the tensile strength and the hardness of corresponding NR/EPDM composite were improved after modification with sepiolite or silica.Thus, the composite reinforced with sepiolite or silica is suitable for many applications, such as internal insulations of rocket motor. © The Authors, published by EDP Sciences, 2016.

Hongthong M.,Defence Technology Institute Public Organization | Hongthong M.,Chulalongkorn University | Angkaew T.,Chulalongkorn University
2016 13th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, ECTI-CON 2016 | Year: 2016

This paper proposed a mathematical model for wide-angle structure to analyze and compare results from the first and second order of Padé approximation. The proposed method aims to improve accuracy and efficiency of the Vectorial Finite Element Beam Propagation Method (FE-VBPM) using the Padé approximation in the wide-angle formulation of the waveguide structure. The computational complexity is greatly reduced by using the transverse FE-BPM with rectangular nodal elements. The boundary condition includes the 2D perfectly matched layer (PML) in its calculation. The proposed method studies wave equations in the frequency domain of an isotropic medium. The relative power is calculated in the tapered waveguide, which is the non-uniform structure formulation. The simulation results are obtained and analyzed on four different angles of tapered waveguide structure. © 2016 IEEE.

Tawiwat V.,Defence Technology Institute Public Organization | Tosapolporn P.,Defence Technology Institute Public Organization | Kedit J.,Defence Technology Institute Public Organization
World Academy of Science, Engineering and Technology | Year: 2011

This research proposes the state of art on how to control or find the trajectory paths of the RRP robot when the prismatic joint is malfunction. According to this situation, the minimum energy of the dynamic optimization is applied. The RRP robot or similar systems have been used in many areas such as fire fighter truck, laboratory equipment and military truck for example a rocket launcher. In order to keep on task that assigned, the trajectory paths must be computed. Here, the open loop control is applied and the result of an example show the reasonable solution which can be applied to the controllable system.

Srihakulung O.,Defence Technology Institute Public Organization | Soongsumal Y.,Defence Technology Institute Public Organization
World Academy of Science, Engineering and Technology | Year: 2011

Among the chemicals used for ammunition production, TNT (Trinitrotoluene) play a significant role since World War I and II. Various types of military weapon utilize TNT in casting process. However, the TNT casting process for warhead is difficult to control the cooling rate of the liquid TNT. This problem occurs because the casting process lacks the equipment to detect the temperature during the casting procedure This study presents the temperature detected by infrared camera to illustrate the cooling rate and cooling zone of curing, and demonstrates the optimization of TNT condition to reduce the risk of air gap occurred in the warhead which can result in the destruction afterward. Premature initiation of explosive-filled projectiles in response to set-back forces during gunfiring cause by casting defects. Finally the study can help improving the process of the TNT casting. The operators can control the curing of TNT inside the case by rising up the heating rod at the proper time. Consequently this can reduce tremendous time of rework if the air gaps occur and increase strength to lower elastic modulus. Therefore, it can be clearly concluded that the use of Infrared Cameras in this process is another method to improve the casting procedure.

Jiradett K.,Defence Technology Institute Public Organization | Ornin S.,Defence Technology Institute Public Organization
World Academy of Science, Engineering and Technology | Year: 2011

With the advance in wireless networking, IEEE 802.16 WiMAX technology has been widely deployed for several applications such as "last mile" broadband service, cellular backhaul, and high-speed enterprise connectivity. As a result, military employed WiMAX as a high-speed wireless connection for data-link because of its point to multi-point and non-line-of-sight (NLOS) capability for many years. However, the risk of using WiMAX is a critical factor in some sensitive area of military applications especially in ammunition manufacturing such as solid propellant rocket production. The US DoD policy states that the following certification requirements are met for WiMAX: electromagnetic effects on the environment (E3) and Hazards of Electromagnetic Radiation to Ordnance (HERO). This paper discuses the Recommended Power Densities and Safe Separation Distance (SSD) for HERO on WiMAX systems deployed on solid propellant rocket production. The result of this research found that WiMAX is safe to operate at close proximity distances to the rocket production based on AF Guidance Memorandum immediately changing AFMAN 91-201.

Tawiwat V.,Defence Technology Institute Public Organization | Narongkorn D.,Defence Technology Institute Public Organization | Auttapoom L.,Defence Technology Institute Public Organization
World Academy of Science, Engineering and Technology | Year: 2011

This research proposes the change of damping coefficient regarding minimum displacement. From the mass with external forced and damper problem, when is the constant external forced transmitted to the understructure in the difference angle between 30 and 60 degrees. This force generates the vibration as general known; however, the objective of this problem is to have minimum displacement. As the angle is changed and the goal is the same; therefore, the damper of the system must be varied while keeping constant spring stiffness. The problem is solved by using nonlinear programming and the suitable changing of the damping coefficient is provided.

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