• Transactions of Materials Processing
• /
• v.21 no.4
• /
• pp.234-239
• /
• 2012

This study examines the forming properties and forming loads needed to increase the edge thickness on the external face of a plate using finite element analysis(FEA). Recently, forming optimization techniques within FEA are being extensively used in designing the optimal forming conditions for processes like forging, extrusion, rolling, and spinning. Most of these existing forming operations involve reducing the volume per unit length, but research for increasing volume per unit length is not very extensive. For this study we chose an automotive engine flywheel which is a welded assembly of a plate and a gear with each component having a different thickness. We considered a forming technique to increase the thickness in order to allow the machining of the gear directly on the external face of plate alleviating the need for a weld. To study various forming techniques, we used the finite element method with the flow stress of material and incremental forming steps. We conclude from this study that the analysis of forming properties and forming loads by using the finite element analysis and testing is useful as a method to increase the thickness per unit length.

• Journal of the Korean Society for Railway
• /
• v.9 no.2 s.33
• /
• pp.160-168
• /
• 2006

The major objective of this study is to investigate the effects and application of external post-tensioning method far steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis, field test and laboratory test fur the lateral dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the lateral dynamic response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease lateral acceleration and deflection on steel plate girder bridge for serviceability. And the external post-tensioning method reduce dynamic maximum displacement(about $10{\sim}24%$), the increase of dynamic safety is predicted by adopting external post-tensioning method. From the dynamic test results of the servicing steel plate girder bridge, it is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method The servicing steel plate girder bridge with external post-tensioning has need of the reasonable reinforcement measures which could be reducing the effect of lateral dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• Journal of the Korean Magnetics Society
• /
• v.8 no.4
• /
• pp.231-240
• /
• 1998

We investigated that the fabrication and reproducing signal characteristics of tri-layered magnetoresistance (MR) element for the high density magnetic thin film heads and sensors. Magnetoresistance curve of tri-layered MR element predicted by computer modeling was saturated above external field of -15 Oe~+22 Oe, and it was shifted to linearized region as large as 4 Oe. In the case of fabricated real device, magnetoresistance curve was saturated above external field of $\pm$15 Oe, and it was shifted to linearized region as large as 4 Oe. As shown in real device, MR response curve was in good agreement with the simulation results. As a result of experimental data of reproducing output signal in real device, it retained normal sinusoidal waveforms in 1~4 Oe external magnetic field. In this magnetic field region, the fabricated heads with tri-layered MR element can be operated with good reproduced characteristics. This will be beneficial to the use of efficient processes of manufacturing elements and the vacuum deposition techniques which control thin film properties.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.5 no.4
• /
• pp.147-153
• /
• 2001

The major objectives of this study are to investigate experimental and analytical behavior of composite steel plate strengthened by external post prestressing method and to study the increasing magnitude of load carrying capacity by the external post prestressing method. With installed strain gauges and LVDT, the change of structural behaviors according to the amount of prestressing force is measured and the effects of shear strengthening according to the degree of angle in tendon are studied. The analytical structural behavior according to the amount of prestressing force is also investigated using finite element method. The effectiveness of strengthening of external post prestressing method is proved and an efficient FEM model is suggested by comparing the test results and analyzing results.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.1151-1152
• /
• 2003

Harmonic analysis, based on finite element method, is popularly used to predict a response of shadow mask to the external excitation from speakers. Since vibration wave travels from speakers to the shadow mask, a finite element model must include all mechanical parts between the speakers and the shadow mask, which increases total time needed in finite element modeling and computation. In this paper, we perform the harmonic analysis on a MF assembly to obtain frequency response function of a shadow mask, and compare the solutions with experimental results.

• KIEAE Journal
• /
• v.4 no.3
• /
• pp.45-52
• /
• 2004

The purpose of this research was to identify the structural characteristics of open housing typologically and systematically. The main method of this study was content analysis and literature review on open housing. This study found that the typological analysis on terminology and the details of the constituents concerning structural patterns in open housing indicated that the main approaches were classified into three criteria such as 'Organization Element', 'Construction Element', and 'Equipment Element'. Organization Element was classified into 'Main Dwelling Unit Area and its Form', 'Room Organization Method', 'Relationship with the Main Dwelling Unit's External Constituents', and 'Combination Method of Support and Infill'. Construction Element was classified into 'Method of Structure' and 'Structural Element Technology'. Equipment Element was classified into 'Method of Using Duct' and 'Wet Zone Method'. The attributes were determined based on these classifications. The results of this study can be used to construct an evaluation tool and further to develop a framework in understanding open housing. Technical research should be conducted on the variables that affect the flexibility of space.

• Structural Engineering and Mechanics
• /
• v.6 no.8
• /
• pp.883-899
• /
• 1998

The strength, deformation and buckling of a large engineering structure consisting of four ellipsoidal shells, two cylindrical shells with stiffening ribs and large holes, one conical shell and three pairs of large flanges under external pressure, self weight and heat sinks have been analysed by using two kinds of five different finite elements - four assumed displacement finite elements (shell element with curved surfaces, axisymmetric conical shell element with variable thickness, three dimensional eccentric beam element, axisymmetric solid revolutionary element) and an assumed stress hybrid element (a 3-dimensional special element developed by authors). The compatibility between different elements is enforced. The strength analyses of the top cover and the main vessel are described in the paper.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.514-521
• /
• 2006

In strengthening structure, the external post-tensioning method which secure clearness in the structure analysis process is adopted to bridge as well as architecture structure. Therefore, the major objective of this study is to investigate the effects and application of external post-tensioning method for steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis and laboratory test for the dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease stress and deflection on steel plate girder bridge for serviceability. It is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method. The servicing steel plate girder bridge with external post-tensioning is the reasonable reinforcement measures which could be secured the stability of dynamic behavior and increase a dropped durability.

• Tribology and Lubricants
• /
• v.37 no.4
• /
• pp.136-143
• /
• 2021

This paper presents the loosening behavior that occurs after the application of an external load to internal and external connection types of dental implants using the finite element method. We use fastening force between an abutment and a fixture to clamp the dental implant system; however, loosening and breakage may occur owing to cyclic external loads. In this study, we considered the initial fastening condition in the pre-load analysis and then investigated the change in stress and contact surface status when applying external loads. After the application of the initial fastening load, we verified that the internal connection-type model exhibited a relatively lower stress distribution than that of the external connection-type one. Moreover, we found that the former model showed a lower stress concentration after the application of the external load. In addition, after the application of this load, we found that the higher the shear load acting on the implant system, the higher the possibility of loosening. The study results showed the change in stress distribution and contact surface according to the connection type of the dental implants and the phenomenon of loosening by cyclic loads. We expect that the results of this study will be useful for the study of reliability and design of dental implant systems.

• Journal of the Society of Disaster Information
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2015

This paper presents finite element (FE) analyses to clarify the effects of external pressure on the residual stresses in a girth-welded steel pipe. At first, FE simulation of the girth welding process is carried out to obtain the weld-induced residual stresses employing sequentially coupled three-dimensional (3-D) thermo-mechanical FE formulation. Then, 3-D elastic-plastic FE analyses incorporating the residual stresses and plastic strains obtained from the preceding FE simulation are performed to investigate the residual stress behavior in the girth-welded pipe under external pressure. The FE analysis results show that the hoop compressive stresses induced by the external pressure significantly alter the hoop residual stresses in the course of the mechanical loading.