จำนวน Repository ( 8 )
การผลิตและพัฒนาบรรจุภัณฑ์ที่ย่อยสลายได้จากวัสดุเชิงประกอบพลาสติก ชีวภาพและเส้นใยธรรมชาติที่ผ่านการปรับปรุงด้วยสารไซเลน
This work aimed to study the improvement of mechanical properties and cost reduction of biodegradable packaging made from polylactic acid (PLA) by using sisal fiber. Because sisal fiber as natural fiber is good mechanical properties biodegradable material and low cost. The variables studied were the addition of sisal fiber surface treatment with epoxy silane and fiber direction. Their effects were investigated by tensile flexural and impact testings and morphology analysis. The results suggested that the addition of sisal fiber increased Young’s modulus Flexural modulus and ultimate tensile stress whereas elongation at break and impact strength tended to decrease. For the effect of surface treatment it was found that tensile and flexural moduli increased with epoxy silane treatment but tensile flexural and impact strengths slightly changed. Surface treatment by epoxy silane led to good interfacial bonding by hydrogen bonding between oxirane ring of epoxy silane and hydroxyl group of PLA. The effect of fiber direction revealed that tensile properties of composite in fiber direction of 0o were higher than those of composite in fiber direction of 45o. Fiber direction did not affect flexural and impact properties.
แผ่นเกราะเซรามิกส์กันกระสุนด้วยวัสดุเชิงประกอบ
This research has been studied and created the ceramic armor plates with composite materials that been proceeded from drying compression process with mold. Al2O3 that use for compression forming has been analyzed by SEM and XRD. It showed that compound and powder particle led to 5 microns-sized. It had flat circle shape of colundum Al2O3 and hexagonal crystal system. Upper punch of molding has designed and analyzed by FEA to 2 forms first form was the end-point had flat face and second form was the end-point had a convex. Upper punch had been made from AISI 52100 with 64 HRC ceramic armor plate had been produced by compression at 1000 kN which had hexagon side shape of width 25.98 mm for each side or height between parallel side of 45 mm. Al2O3 had been compressed to investigate the distribution of relative density for the height after compression of 15 and 30 mm by analyzing 4 cases that consist of 1.) a case of smooth face of upper punch which has green compact of 15 mm height 2.) a case of convex face of upper punch which has green compact of 15 mm height 3.) a case of smooth end face of upper punch which has green compact of 30 mm height 4.) a case of convex face of upper punch which has green compact of 30 mm height. The result of this study is to propose the distribution of relative density on horizontal axis as it is a relative radius and vertical axis is a relative distance from the upper punch that is an axis of moving down action. This study found that the distribution of relative density form had analogous form for these 4 cases the density had few differences and had high value at the town edge of green compact due friction between die wall and upper punch. The ceramic armor plate has been set up on UHMWPE fiber plate and used special silicone to connect them together then will get the NIJ 3 standard of ceramic armor plate with Composite materials
การศึกษาสมบัติทางกลของโพลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบสำหรับล้อ Run-flat
This research project aimed to test the mechanical properties and the capability in wear resistance of ultra-high molecular weight polyethylene composite as well as determine the optimal formulation of UHMWPE-based composites which had a main component of aluminum oxide. The developed formula was used in the manufacture of run-flat wheels and thus applied to build run-flat wheels with an understanding of the proper molding conditions under the run-flat wheel forming process. Two materials used in the research consisted of super-high molecular weight polyethylene (UHMWPE) as the base material and the additive of aluminum oxide (Al2O3). The parameters employed in the hot compression process to obtain the specimen for the experiment consisted of compressive force temperature time and the ratio between super-high molecular weight polyethylene and aluminum oxide. The test for mechanical properties consisted of an impact test a hardness test according to the ASTM D2240 standard a tensile test according to the ASTM D638 standard type I and a wear test according to the ASTM G77 standard. The results indicated that a hot compression condition under a pressure of 5 MPa a temperature of 210°C for 90 min and using 5% Al2O3 HTM 30 material caused mixed uneven powder particle sizes between 2 to 5 µm. The tensile test results inferred the yield strength of 20.52 MPa ultimate tensile strength at 29.96 MPa breaking strength at 22.83 MPa elongation at break at 265.8% and modulus of elasticity at 784.46 MPa. The highest hardness was 62 shore D the high impact strength was 586.8 J/m and it was displayed for the wear rate of hot compression specimens made of UHMWPE mixed with 5% HTM-30. Moreover it introduced a coefficient of friction the wear rate and the density of 0.12 8.66E-11 mm3/N.m and 1.2446958 g/cm3 respectively.
แผ่นเกราะโลหะกันกระสุน
This research project aimed to analyze and design the pattern of a bulletproof metal armor plate as well as build a bulletproof metal armor plate for a small armored regular truck. The methodology consisted of the NIJ standard test and the finite element analysis. The bulletproof plates created were tested for a real firing. Their firing results were compared with those of NIJ-standard using a finite element program in this case applying with the program Ansys/Explicit Dynamic. SolidWorks program is employed as a tool to design and create 3D models of armor plates and bullets. The materials taken in the finite element simulation were SKD11 and SUS304 and the parameters utilized in the research were material types hardness values spacing between the plates and thickness. In the case of two armor plates stacked SKD11 material was designed for the first armor plate to be hit by the bullet. It served to destroy bullets. In addition the second armor plate made of SUS304 material served to absorb energy and obstruct the movement of bullets. For testing a 30-06 caliber M2 AP 166 Gr bullet was selected at a 0-degree angle and the velocities measured and set by the Ansys/Explicit Dynamic program were 901.7 m/s and 880 m/s respectively. The front plate made of SKD11 material with a thickness of 10 mm and the back plate made of SUS304 material with a thickness of 10 mm were fired 1 shot. The results showed that the bullet could penetrate the front armor plate but not penetrate the back-armor plate. In the NIJ 3 standard tests the shooting with a 7.62x51 mm NATO FMJ 148 Gr shell at a 0-degree angle for 5 times with velocities equal to 846.4 841.3 839.1 838.2 and 845.3 m/s was performed on the stacking front and back armor plates both made of SUS304 material with a thickness of 8 mm. The bullet velocity simulated by the Ansys program was 847 m/s resulting in the front plate having a bullet penetration and a slight bulge on the back plate. From the finite element simulation results and the actual test results it was found that the damage to the armor plates detected by both methods was consistent. Therefore the finite element program was selected to simulate the damage of armor plates resistant to penetration according to the NIJ standard Level 4. The results of the research could be concluded that the use of armor plates stacked with suitable different materials in multiple layers would affect the penetration resistance. Increased thickness and optimal spacing between the armor plates were important parameters in penetration resistance. Moreover it revealed that the higher the material hardness the better its ability to resist penetration. In particular this suggestion should be applied to the first armor plate or front armor plate.
การศึกษาพารามิเตอร์ในการขึ้นรูปแผ่นเกราะเซรามิกส์รูปร่างหกเหลี่ยมกันกระสุน
This research had two objectives that were to study parameters for forming bulletproof ceramic armor plates and to create a model of a bulletproof ceramic armor plate for small armored regular trucks. The parameters used to form a ceramic armor plate contain the thickness of the armor plate and the compressive strength which affects the density distribution of the green compact. A ballistic ceramic armor plate with a hexagonal shaped material was created as a concave bulletproof plate. Extrusion results displayed that the hexagonal material was formed at a very high density on the side surface of the armor plate but with uneven capacity distributed across the overall plate due to the friction occurring on the wall of the mold. The finite element method particularly at the Ansys/Explicit Dynamic tools were applied to analyse the damage of bulletproof plates. The model of a concave-shaped bulletproof plate was set for the SKD11material influencing the changes in the direction of the bullet firing when the bullet hit the bulletproof plate at a velocity of 880 m/s in accordance with the NIJ 4 standard. The bullet was made of tungsten carbide and the ceramic armor plate was built with a size of 300×300 mm and thicknesses of 14 16 18 and 20 mm. The bullet was fired into the center part and onto the curved surface of the ceramic plate. The result shows that the armor plate could not resistant to penetration. In this situation the direction of the bullets movement against the armor plate especially at a curved surface as a slope could result the deflection of the bullet direction as well as reduction of penetration capability.