In this article, we reported the characterization of mechanical properties for several scaffolds fabricated by different techniques: bio-plotter technique and WNM(wire-network molding). Firstly, we constructed numerical models for ABAQUS: a commercial computational analyzing program. Using ABAQUS, effective compressive are calculated and compared with the experimental results from UTM tests. The results show that the stiffness of the scaffold fabricated by WNM is stronger than that by bio-plotter technique.
The wheel is an active area of automobile component design and development. The wheel must be durable enough to tolerate significant loads and harsh environment. Temporary tire substituted for spare tire is made in a half band wheel size. Therefore this temporary tire is carried out lightweight and fuel saving of automobile. In this research, structural analysis and fatigue analysis of the temporary steel wheel are carried out using ANSYS 3D-modeling. The model is verified by the equivalent(von-Mises) stress analysis obtained from the ANSYS static structural analysis. Fatigue analysis is performed at the equivalent stress considering the automobile load and moment. Finally, this temporary wheel can be used temporary but not continuously.
About 30 percents of the energy produced by a gasoline engine is used to move a car, and nearly 70 percent is lost through waste heat. A thermoelectric generator module can harvest some of this waste heat. Thermoelectric power generation voltage and current according to the temperature change at high temperature part of thermoelectric module is increased. The reason is that the Bi-Te based thermoelectric module which is to recover waste heat of exhaust gas is increased according to high temperature. The maximum power of 5.1 Watt at 230℃ was generated at energy harvesting system using exhaust gas from internal combustion engine. Thermal power module temperature difference between both ends of the high temperature and low temperature section increases the maximum output power increases. The key factor of Thermoelectric power generation performance is the temperature difference between the both ends
A 2D axisymmetric numerical analysis was performed to study the characteristics of charge process inside solar thermal storage tank. The interfacial area density and inertial resistance of filler material are selected as simulation parameters. The interfacial area density is varied as 800, 2000, and 4000 1/m. The inertial resistance is varied as 1, 3, and 5 1/m. When the interfacial area density increases from 800 to 4000 1/m, the discrepancy of the temperature distributions between the filler and heat transfer fluid decreases. As inertial resistance increases from 1 to 5, both of the temperature and fluid flow pattern changes considerably.
This study is for a pipe cutting apparatus for use in a process of a pipe. The system refers to a novel structure comprised of a main bed, a feeder part and a cutter part. The feeder part is comprised of an AC servo motor unit, a feeding gear unit, a LM guide and a rail. The cutter part is comprised of a blade unit consisting of a blade for cutting, a AC servo motor to rotate the blade unit and a clamp unit to fix the pipe. This study proposes a mechanism of a product by designing the system and analyzes the cutting power. This study will be used as basic data for the design by analyzing the vibration and the structure
A three dimensional numerical analysis was performed to study the cooling performance of xEV battery module depending on cooling fluid inlet position. Depending on the inlet position from the top, case 1 (top inlet), case 2 (middle inlet), and case 3 (bottom inlet) are selected. For the case 1, the temperature of the battery near inlet was higher than that of the battery near outlet. For the case 2 and 3 the temperature of the battery near inlet was lower than that of the battery near outlet. From the analysis result, the cooling performance is higher in the order of case 2, case 3, and case 1.
In this study, the system Jacobian matrix is derived using symbolic method and developing general program to analyze quasi-static problem for mechanical system. The constraint equations in terms of generalized coordinates are generated symbolically by using the symbolic computation tool such as Maple, and then, the differentiation can be carried out easily. An algorithm based on Lagrange polynomial is developed to ensure efficiency and accuracy associated with numerical differentiation. The derived Jacobian matrix for a system is proved to be valid and accurate both analytically and through solution of numerical example. In order to verify the accuracy of a program, I was verified applying the 4-bar system
In this paper, we present a CMOS voltage regulator for application in electric device. This works shows that unlike the traditional voltage converter, this regulator can achieve high efficiency with a good step-down voltage ratio. The circuits which are implemented in this paper is simulated with LT SPICE tool of computer.
The lay outs in this thesis is based on basic theories and the test the performance of the product by wind tunnel test and vehicle test. Furthermore, in order to find out the effect of structure change on hub which is one of the components of wind turbine, I compared the actual performance between the existing model and the modified model thoroughly. To improve the performance of wind turbine, I modify the structure of the hub and analysing base model and modify model by using Star-CCM+. As a result, I found out the wing-shaped hub used model stablizes the spin in shorter time than existing model. Therefore, with the optimal blade selection, the structure modification on hub is a considerable variable on wind turbine design which is aiming better performance.
In this paper, heat treatment on the cutting device for automatic welding electrode is proposed. The electrode can be fed continuously by general automatic welding. When the leading end of wire is bent, it must be cut with the constant length. The wire has been cut by manual method previously but the automatic cutter device is proposed and designed in this study. These new device parts are designed and the heat treatment of cutter is determined analytically. The numerical three-dimensional analysis is carried out by means of DEFORMTM-HT, the common heat-treatment software. The meshes are divided with tetrahedral elements. As the result, the highest hardness is observed at the end edge of cutter and especially the hardness at edge is reached even HRc 64.3. The layer, 90% of which consists of martensite structure, is extended to the end edge of cutter. And the layer, 50% of which consists of the micro-structure, becomes its middle area. Because the mechanical property can be predicted by this analytical approach, it is not necessary to have any onsite heat treatment. The life of cutter can be improved by using this study result.
In automobiles, the main source contributing to the resulting car interior noise is the combustion engine, including gearbox, driveline, intake and exhaust system, wind, tire. Interior noise of a vehicle is usually caused by the vibration of the vehicle’s body transmitted from engine und driveline through the mounting system. The vibration and sound radiation is extremely complex. The final result of interest is in any case the sound pressure in the driver’s ear canals. The transferpath are separated into structure-borne and air-borne path. In oder to estimate the contribution of these components to car interior noise, the total sound pressure in car interior is estimated by using Transferpathanalysis method. In dies paper, experimental simulation has been carried out to analyze transfer characteristics for car interior noise transferred from sound source of the engine and driveline. The results from this study could be applicable for optimal design of noise reduction system in car.
Mechanical stimulation has been reported to improve cell growth in bone and cartilage regeneration. Various research groups have described their own bioreactors that stimulate cell-seeded scaffolds. We have developed a bioreactor capable of applying controlled compressive loading to a cell-encapsulated agarose hydrogel. To compare the effect of mechanical stimulation on agarose hydrogel, we used one control group (static mode) and five experimental groups. The results show that the intermittent_3sec conditions improve proliferation of cells better than the other conditions studied.
Among many potential problems associated with automobiles, the problem regarded as most sensitive and important to the customers is the automobile’s quietness. In particular, because the trend toward the high-performance automobiles is increasing, the quietness should be considered reflecting the increasing demand of the customers for the comfort of automobile ride. Road noise is the low-frequency range in the region of 20Hz to 350Hz, generated when the tires are making contacts with the rough road surface while the automobile is running, in which the noises are resonating within the passenger compartment or with the automobile suspension. In this research, among the factors related to the road noise, the influencing factors associated with the suspension and the tire design were investigated. In particular, among the tire design factors, the structure and the rubber material were investigated as the influencing factors, and for the investigative purpose, experimental tires were manufactured and road noise evaluations were conducted thorough actual feeling tests. Then the test results and correlations were analyzed using the 6-Sigma statistical method. Results from this study shows that, among the tire design factors, the apex is the most influencing factor, in which the height of the apex is the key. The influential factors were found out to be apex height, belt angle, and tread hardness, in that order, and when the suspension is of a same kind, the tendency of the road noise was found to be similar.
Tool tips of the circular saw for the steel cutting have commonly applied to brazing type welded the saw body to tips. In this case, when the tool tip is required to the exchange, many problems were occurred as the exchange cost is high and its time is long. In this study, to resolve the brazing type circular saw, the insert type circular saw has designed and made. Also, to confirm the performance of new type circular saw, the various experiments were carried out under condition of tip's shape and machining conditions.
This study was to develop the automatic fin tube cutting machine, equipped with semi-automatic supplying board, automatic transfer equipment, fin tube holder, and cutting equipment assembly for the effective and safe fin tube cutting. The development of the automatic fin tube cutting machine resulted in improving 150% of productivity, 300% of cutting length precision, and 230% of a vertical angle precision on the cutting plane. In addition, we were able to secure safety of the workers and to automate production management, and further to reduce environmental pollution by recycling cutting chips.
The application of sublimation transfer printing is widely expanded in the textile industry according to the growth of IT technology. Therefore, its improvement of manufacturing process is strongly needed. In this paper, new manufacturing process of sublimation transfer printing by combining conveyor system and hot plate pressing is developed. New process has improved quality and productivity of sublimation transfer printing. It is shown that the new process has better indices than existing process in the required time, man power, production output and sales. New process is able to cope with mass production and various manufacturing condition actively.
In aquaculture operations with nets including scallop aquaculture, there exist many problems as the management of fishing gears is dependent on the traditional method that has been using the pure labor forces. These give rise to the environmental contamination and increase of total fishery costs because they prevent the fishermen from reusing the fishing gears. Due to the eco-friendly issues and aggravation of the management cost, the need to automate the washing operation of the fishing gears has been required consistently. In this study, development of scallop fishing gear washing apparatus was carried out. We conducted the preliminary experiments applying Taguchi experimental method in order to find the influential factors and optimal levels to the washing performance. Based on these result, we designed the structure and the kinematic mechanism of the fishing gear washer. Final prototype was verified to be effective in maximizing the washing rate through the performance test.