The objectives of this research were to study the stress intensity in run-flat metal wheels and to design a new type of run-flat wheels that can be used in a small armored regular truck. Experimental methods and finite element methodologies were applied in the research process. The results obtained by comparing the strain values from the two methods demonstrated the consistency of both methods. The differences in stress values were in 10 -16 percentages which could confirm the capability to analyze the stress distribution and deformation of run-flat by a finite element method. Proven processes and procedures in Pre-processing with SolidWorks Simulation were utilized to design run-flat wheels and a reverse engineering process was next used to create wheel rims and design the cross-sectional shape of new run-flat wheels made of composite materials which have an important reactant; a polymer group and aluminum oxide powder added to enhance the strength. The designed parameters consisted of 1) the width of the run-flat wheels 2) the internal and external radius in which the internal radius depending on the size of the wheel rim and the outer radius which is a variable that determines the height of the run-flat wheels 3) the design of a lockset for tightening the run flat wheels to the wheel rims 4) materials used in the structure of the run-flat wheels and 5) tire pressure. The run-flat wheels designed and built into three-piece parts were designed for ease of wheel assembly or disassembly out of the wheel rims. By analyzing the intensity of stress accumulated in a conventional run-flat wheel (run-flat metal wheel) the stress generated in a run-flat wheel did not exceed the limit of the Yield stress and had a safety value between 3-5 times for new run flat wheels with a maximum stress of 26 MPa. Sizing and cross-sectional dimensions of run flat wheels thus resulted in stress which was in the range that could be withstood and acceptably employed. It was also possible to reduce the height of the flat wheels to make the rear flats lower and increase the width of the run flat wheels which would help distribute more weight to the wheel rims.

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.

The bulletproof plates with materials that can convincingly be destroyed by the 7.62 mm bullet with its speed at 878 ± 9.1 m/s were developed by designing according to the National Institute of Justice Level 4 (NIJ 4). The plates were made of two flat sheets stacking SKD11 and SUS304. Their components were composed of the front and back plates; the first sheet made of SKD11 material hardening at 65 HRC with a thickness of 6 mm and the back plate made of SUS 304 material with a thickness of 5 mm. The finite element method was applied to simulate and analyze the results to demonstrate the bullet resistance to the perforation by setting perpendicular sheet to the bullets. Therefore the simulating studies for the bullet firing were demonstrated by locating its angles of 15 30 45 and 60 degrees to the SKD11 sheet with a thickness of 6 8 and10 mm coupled with the SUS304 sheet with a thickness of 5 6 8 and 10 mm. These plates were stacking into two layers then the finite element method was applied to simulate one at a time. The results showed that the first sheet of SKD11 with 6 mm of thickness could resist the perforation of the bullet at 60 degree and the plate thickness of 8 and 10 mm could start resisting to the perforation at 45 degree. The second sheet of SUS304 with the thickness of 5 6 8 and 10 mm were incapable to resist to the perforation and the refraction of the bullet direction as good as that of SKD11. Therefore the principle applying two metal sheets stacked into layers was essential to impel the resistance of the bullet perforation and change the direction of the bullet.

This research aims to predict the thickness loss of parabolic forming by using hydromechanical deep drawing (HMD) process. The methodology used is the finite element method on the uncertainty of the mechanical properties for 1 mm thickness SPCC sheet metals. The properties consisted of three aspects: strength coefficient (K) strain hardening exponent (n-value) and plastic strain ratio for all three axis (r0 r45 and r90). Multiple simulations were completed by randomly selecting K n r0 r45 and r90 values following the distribution obtained from the uniaxial tensile test. The results would be analyzed by using the regression equation to create the equation to predict the thickness loss of the test pieces obtained from the formation process using the K n r0 r45 and r90 variables without the use of finite element method. This would results in a decrease in the simulation time. Based on 30 experiments of uniaxial tensile test it shows that the sheet metal properties are normally distributed. After that 60 cases of the five variables were randomly selected to simulate the formation by using the finite element method. Finally the results obtained from the aforementioned simulation is analyzed and generated into a regression equation. From the comparison between the value predicted from the regression equation and the result obtained from the formation process it can be seen that the regression equation can effectively predict the thickness loss when the five variables are under the same distribution properties. However the efficiency will decrease when the values of the five variables are beyond the distribution properties obtained from the experiment. In addition the uncertainty of mechanical properties of sheet metal in the simulation displays the chances of discovering test pieces with over 40% thickness loss. The simulation resulted in 5 damaged test pieces accounting for 8.33% of the total process.

In general for the refrigeration the cooling coil is almost used to be the device to decrease the temperature. Thus in order to design heat exchange we should study the heat transfer into the cooling coil. This research proposes the numerical using finite element method for calculating the temperature at any position of the cooling point for considering to porous media. After that to create an algebraic equation fmite element for writing the program to search the solution by estimating the temperature. The research demonstrates that the changing of temperature will be decreased to saturated condition that is the temperature around the region of the cooling coil model edge will be decreased. The longer time the lower temperature around each position will decrease respectively until the temperature at each position inside the model are the same as region of the cooling coil model edge. Therefore this search result can be the basic for the comparison with the similar problem of other