Advanced Materials Research Vol. 658

Abstract: For the common diseases of the hinge joint, a new structure named thin-film layer is presented to simulate its function in finite element model. Through the field test of an on-built bridge, real measured results are used to determine the parameters of the layer in the model. The model result shows that the deformations of the hinge joint include vertical shear dislocation and transverse bending deformation, which may lead to different kinds of diseases of the structure. A certain amount of reinforcements with reasonable configuration focusing on intensifying the whole structure is preferred.

Abstract: Design reliability is analyzed for the interference fits of the railway wagon wheelset with 30 ton axle weigh. Aim focus on eliminating fretting fatigue damage of the wheelset. An extreme wheelset loads set is deduced by which can yields the thermal mechanical loads on the wheel same to the code AAR S 660. Integrated wheelset model of finite element method is applied to calculate the stresses on the fits to consider the physical fit relationship of wheelset, in which the rail pieces, wheels, axle, bearings, and adapters are fitted together by contact phases. It is revealed that the fits are all in the press stress states for the original design. But the stresses seem smaller than the least reasonable value for the reliable fits between wheels-axle. An improvement suggestion is provided to rise the fit scale to 0.23 mm equal to 0.01 percentage of the wheel-hub hole diameter. Calculation results verify that the press stresses have been controlled in the reasonable range.

Abstract: Design reliability of the railway wagon axle with 30 ton axle weigh is assessed on a basis of the code EN 13103 loads set. Constraint effects of the interference fits between wheels – axle and bearings – axle are taken into account. Integrated wheelset model of finite element method is applied to calculate the axle stresses, in which the rail pieces, wheels, axle, bearings, and adapters are fitted and analyzed together. Results reveal that the maximum stress section is at outer side close to wheel seat, different from the prediction of inner side close to wheel seat by the code analytic method. Under requirement of 3, 000, 000 km and 99 percentage of confidence, the evaluated axle design reliability is 0.9987 if manufacturing by the existent LZ50 axle steel. And if by the material EA1N or EA4T of the code EN 13103, the present design meets also the requirement of the code EN 13103.

Abstract: In this paper, the most serious loads configuration of High-Dynamic Flight Simulator (HDFS) was found firstly by rigid-body dynamics analysis, then level-by-levelfinite element analyzing based on substructure method for HDFS under the configuration above was carried out, from which we got the statics characteristic of arm/gondola frame/gondola and the dynamics characteristic of the overall structure respectively. Such analysis strategy couples the stiffness matrix and mass matrix of lower-level structures to upper-level structures, and takes the deformation of upper-level as boundary condition for lower lever by displacement coordinate relationship between them, consequently, the accuracy of this strategy is reliable, and the computational efficiency is evidently improved. Analysis results show that the statics and dynamics characteristic of HDFS could be carried out by the level-by-level analyzing strategy effectively and soundly. This kind of analysis strategy is able to extend to other multi-level structures, such as flight simulator, centrifuge, multi-axis turntable et al.

Abstract: Presently, large passenger vehicles are known to have high risk of an injury due to accident and insufficient of safety regulation. The strength of seat is one of important issues that affect to injury level of passenger. Therefore, suitable structure strength and design of the seat are very important to prevent injuries and passenger life. This study was to evaluate strength of the seat structure for bus according to preliminary safety regulation of Department of Land Transport. Finite element analysis is employed by using a static load. The seat model was simplified and simulated. Stress and impact scenario between seat-back and back of manikin will be investigated. The strength and deflection of the seat will be evaluated. This study is expected to provide the seat model which will be safe and satisfied according to the regulation.

Abstract: Since the vehicle accident is one of the major causes of dead and injury in Thailand, especially the large passenger vehicle. The seat anchorage was often damaged and lead to high number and critical of patient. To improve the safety of large passenger vehicle, seat anchorage should be investigated. The aim of this research was to analyze strength of seat anchorages for the bus according to European standard ECE Regulation 80 using finite element method and DOE(Design of Experimental) approach. In this study, the boundary conditions on finite element model of seat structure were defined according to the regulation. It is expected that the simulation techniques could be advantaged for seat anchorage analysis. This result will be used for further improvement of the bus seat anchorage design for safety and cost reduction in design processes.

Abstract: Recently, due to the rising of oil prices, interest in FCC Unit (Fluid Catalytic Cracking Unit) energy recycling is increasing. FCC Unit (Fluid Catalytic Cracking Unit) is a mechanical used to convert bunker C oil into high quality gasoline. Pressure vessel of FCC Unit is that refining the crude oil when is operating in high-temperature and high-pressure environment. So it needs analysis of structure carefully. In this paper, FEA (Finite element analysis) of the FCC unit was performed to evaluate its structural stability and weight reduction. The equivalent stress of the FCC unit was investigated and compared against the ASME code design specifications. The area of high stress concentration with maximum stress higher than the prescribed value was analyzed locally to carefully evaluate the stress. Finally, we were reduces the thickness of the CA nozzle in FCC unit, and it was satisfied structural stress.

Abstract: Since stainless steel has significant characteristics such as its superior corrosion resistance, durability, aesthetic appeal etc., it has been utilized as structural members in buildings. Recently, ultimate behaviors and curling influence in austenitic stainless steel single shear bolted connections with thin-walled plane plates have been investigated by T.S. Kim. In this paper, finite element analysis (FEA) has been conducted based on the existing test results of angle bolted connections in fabricated with austenitic stainless steel. The validation of the numerical analysis prediction was verified through the comparison of test results for fracture mode, ultimate strength and curling occurrence. Curling (out-of- plane deformation) also observed in the connections with a long end distance. The curling caused the ultimate strength reduction and the ultimate strength reduction ratios (varied from 12% to 25%) caused by curling have been estimated quantitatively through the comparison of FEA results of FE models with free edge and restrained curling.

Abstract: The ability to predict the forming severity with respect to crack and failure is essential to analysis of sheet metal forming process. The forming limit diagram (FLD) is commonly used to gauge the formability of sheet metal. In this article, forming limit diagrams of cold rolled carbon steel (JIS-SPCC), which widely used to produce the parts of automobile, are obtained by performing experiment and FE simulation with the Nakajima-test. By using the GTN (Gurson-Tvergaard -Needleman) damage mechanical model, a failure criterion based on void evolution was examined in this FE simulation. The parameters of GTN model are determined through comparison of experimental and numerical result with Nakajima-test. These parameters acceptably can be used in GTN model using given material. In application case, the reliability of the GTN model for failure criterion in simulation with automotive part was confirmed.

Abstract: In order to resolve the theorized design problems on the bionic non-smooth drag reduction surface of an arc-shaped revolution body, which mainly include the structure morphology and spatial arrangement of the non-smooth point, a kind of designing method on the bionic non-smooth drag reduction surface is presented based on biological phyllotactic theory, and the mathematical equation of the arrangement of the non-smooth point on the arc-shaped drag reduction surface has been established, the effects of the phyllotactic parameters on the arrangement form and density of the non-smooth point have been discussed, and the arrangement of the non-smooth point on an arc-shaped revolution body surface has been designed by using a 3D software. Research results have shown that the arrangement density of the non-smooth points increases with the decreasing of the phyllotactic coefficient, and the area ratio of the no-smooth point to the surface of revolution body increases with the geometric parameter of the non-smooth point.