จำนวน Repository ( 7 )

การวิเคราะห์มุมเอียงและความหนาของแผ่นเกราะที่มีผลกระทบต่อการต้านทานการเจาะทะลุของกระสุนบนแผ่นเกราะอลูมิเนียมและสแตนเลส ด้วยระเบียบวิธีไฟไนต์เอลิเมนต์
การวิเคราะห์มุมเอียงและความหนาของแผ่นเกราะที่มีผลกระทบต่อการต้านทานการเจาะทะลุของกระสุนบนแผ่นเกราะอลูมิเนียมและสแตนเลส ด้วยระเบียบวิธีไฟไนต์เอลิเมนต์

This thesis was an analysis of the significance of angle of inclination and the thickness of the armor plate on the penetration resistance of bullets on aluminum and stainless steel armor plates determined by the finite element method. In this study the information results obtained from actual firing of bulletproof armor and the finite element simulation according to NIJ 3 standards were compared to create a pattern of bulletproof and bulletproof armor using the SolidWorks program. The simulation model of the armor shooting was created by the Ansys/Explicit Dynamics program. The bullet material was 7.62 mm tungsten carbide (WC). There were three plate types used in the simulation were made of different bulletproof armor materials: 1) stainless steel SUS304 using for the plate thickness of 5 6 8 10 14 20 30 40 45 and 55 mm. 2) aluminum AL7075 using for the plate thicknesses of 6 8 10 and 20 mm. Additionally 3) tungsten carbide using for the plate thicknesses of 6 8 and 10 mm. Each of these plates had a width x length of 300 x 300 mm. The simulation models were divided into two types: Type 1 a simulation firing at one plate at a time. Type II a simulation firing at two layered plates stacked together without any gaps between plates. The front and the back plates made of stainless steel and aluminum respectively or tungsten carbide and stainless steel respectively were determined. The angles of firing at bulletproof armor were set at 0 30 and 45 degrees. The output results were that in Type I the stainless-steel plate with a thickness of 30 mm or more could resist the penetration of bullets. However in Type II 2 stacked layers of the armor plates using the front stainless plate with a thickness of only 20 mm and the back aluminum plate with a thickness of only 8 mm could provide the same constructive results as those of tungsten carbide and stainless steel plates for the front and back plates with both thickness setting at 16 mm. All of them showed the resistance of the penetration to the bullets. More observation was that the increases in angles as a result enhanced more resistance of the bulletproof plates to bullet penetration.

2566
ความสามารถในการดัดขึ้นรูปและกลไกความเสียหายของโลหะแผ่นอลูมิเนียม AA6016
ความสามารถในการดัดขึ้นรูปและกลไกความเสียหายของโลหะแผ่นอลูมิเนียม AA6016

Aluminium alloys was used in the automotive parts industry increased for compensate steel parts material due to its lightweight and good surface. Since aluminium alloys are there relatively low mechanical properties although they can be deformed easily but the major limitation is their low formability. Especially the less bending radius which is often bending surface damaged easily. In the present work five-difference ratio of sheet thickness and bending radius for study to the bendability of cold rolled aluminum alloys AA6016 at low bending radius. The bending test by Air-bending method according to ISO 7438: 2010. To compare the results every 15 degrees. The mechanical behaviour surface roughness microstructure and damage evolution in the fillet region were analysed by experimental research. The experiment clearly showed that the Spring-back angle and bendability tend to decrease as the bending angle and material thickness increase. Due to the high tensile stress on the bending surface it effected to the surface roughness increases rapidly and led to the damage on the specimen bending surface. The initial cracks occur on the middle of the outer surface curvature and propagation in the shear plane pattern to the middle of the sheet thickness along the grain boundary. This is the consequence of plastic deformation by bending test.

2565
การปรับปรุงสมบัติทางไทรโบโลยีของผิวอะลูมิเนียมด้วยกระบวนการอโนไดซ์เสริมนาโนไททาเนียมไดออกไซด์
การปรับปรุงสมบัติทางไทรโบโลยีของผิวอะลูมิเนียมด้วยกระบวนการอโนไดซ์เสริมนาโนไททาเนียมไดออกไซด์

Aluminium was used in many industrial applications due to good properties such as ductile high corrosion resistant and high electrical conductivity. Since wear resistance of aluminium was very poor so that it was a limitation of using this material in several conditions. In this research aluminium was improved the wear resistance properties by using anodizing process and adding some titanium dioxide particles on the surface. The effect of anodizing process duration on the wear resistence property was studied. It was found that the process duration and amount of titanium dioxide play the important role on improvement of tribological properties of aluminium.

2563
การเพิ่มสมบัติทางไทรโบโลยีของผิวอลูมิเนียมด้วยกระบวนการทางเคมีไฟฟ้ากับนาโนซิลิกอกนไดออกไซด์
การเพิ่มสมบัติทางไทรโบโลยีของผิวอลูมิเนียมด้วยกระบวนการทางเคมีไฟฟ้ากับนาโนซิลิกอกนไดออกไซด์

Aluminum is a lightweight material which are popularly used in various parts of the industry. However there are some limitations on the tribological properties such as abrasive wear and friction when it was compared to other metals. Tribological properties of aluminium was improved with anodizing process and silicon dioxide supplement. the effect of time on surface structure and friction coefficient were studied with with scanning electron microscope and sliding wear tester. It was found that friction coefficient of aluminium was decreased after improvement process was applied.

2563
ผลกระทบของตัวแปรในกระบวนการดัดขึ้นรูปแบบอิสระที่ส่งผลต่อพฤติกรรมการดีดตัวกลับของโลหะแผ่นอลูมิเนียมผสม AA6016
ผลกระทบของตัวแปรในกระบวนการดัดขึ้นรูปแบบอิสระที่ส่งผลต่อพฤติกรรมการดีดตัวกลับของโลหะแผ่นอลูมิเนียมผสม AA6016

Springback behavior is a major problem of sheet metal forming process. Especially aluminum alloy which often encounter such problems often. At present aluminum alloy is increasingly of used in the automotive industry for replace of the steels due to its lightweight and good finished surface. This work aims study to springback behavior of cold rolled aluminum alloy (AA6016) during air-bending process by ISO7438/2010 test standard. To analyze the influence of bending process parameter are included: sheet thickness punch radius bending angle die open and the ratio of bending radius and material thickness (r/t) effecting to springback behavior. The results are clearly that the springback angle is likely to increase with increase of the punch radius size of die open and the ratio of punch radius and sheet thickness and the springback tenor to decrease when the sheets thickness and bending angle increased. The increased bending angle will resulted to bending surface region is roughness increase and crack occurred to follow. As a result the bending force and the springback angle decreased.

2561