• Earthquakes and Structures
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• v.17 no.6
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• pp.611-621
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• 2019

Precast concrete structure has many advantages, but the assembled seam will affect potentially the overall seismic performance of structure. Based on the sidewall joint located in the bottom of assembled monolithic subway station, the main objectives of this study are, on one hand to present an experimental campaign on the seismic behavior of precast sidewall joint (PWJ) and cast-in-place sidewall joint (CWJ) subjected to low-cycle repeated loading, and on the other hand to explore the effect of shape and position of assembled seam on load carrying capacity and crack width of precast sidewall joint. Two full-scale specimens were designed and tested. The important index of failure pattern, loading carrying capacity, deformation performance and crack width were evaluated and compared. Based on the test results, a series of different height and variably-shape of assembled seam of precast sidewall joint were considered. The test and numerical investigations indicate that, (1) the carrying capacity and deformation capacity of precast sidewall and cast-in-place sidewall were very similar, but the crack failure pattern, bending deformation and shearing deformation in the plastic hinge zone were different obviously; (2) the influence of the assembled seam should be considered when precast underground structures located in the aquifer water-bearing stratum; (3) the optimal assembled seam shape and position can be suggested for the design of precast underground concrete structures according to the analysis results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.493-499
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• 2009

The assembled structures of pressure rice cooker are consisted of oven, top heater plate and locking ring. Since pressure is applied to the assembled structures, it should be necessary to check the safety. In this paper, structural analyses are performed from design and fracture point of view. For the design point of view, linear analysis is performed to assembled structure and for the fracture point of view, nonlinear analysis is performed to locking ring. From these results safety evaluation technique for the assembled structures of pressure rice cooker is proposed.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.213-218
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• 2001

Presented are the STM images of self-assembled monolayer of 2-mercaptoethanol on Au(111). Striped structures of ($6{\times}3_{\frac{1}{2}}$), ($5{\times}3_{\frac{1}{2}}$), ($4{\times}3_{\frac{1}{2}}$) and compact-($5{\times}3_{\frac{1}{2}}$) were observed after annealing at $80^{\circ}C.$ Analysis of the ordered structures revealed that the basic fundamental units of the ordered structures were three crystallographically non-equivalent ($3_{\frac{1}{2}}{\times}3_{\frac{1}{2}}$) $R30^{\circ}$ assemblies, and that the way of combination of the assemblies produced the four different structures. The($6{\times}3_{\frac{1}{2}}$) structure ( $\theta$ = 0.33) was composed of one ($3_{\frac{1}{2}}{\times}3_{\frac{1}{2}}$)$R30^{\circ}$ assembly, while the ($5{\times}3_{\frac{1}{2}}$) ( $\theta$ = 0.30) and ($4{\times}3_{\frac{1}{2}}$) ( $\theta$ = 0.38) structures were consisted of two ($3_{\frac{1}{2}}{\times}3_{\frac{1}{2}}$) $R30^{\circ}$ assemblies, separated by 5a and 4a, respectively. Furthermore, the compact-(5X 3½) structure ( $\theta$ = 0.50) was obtained by overlapping three ($3_{\frac{1}{2}}{\times}3_{\frac{1}{2}}$) $R30^{\circ}$ assemblies. In spite of the diversity in the adsorption structures, all the adsorption sites of 2-mercaptoethanol were fundamentally identical. On the other hand, the unannealed primitive SAM of 2-mercaptoethanol was characterized by two observations: a short-range order keeping the adsorbed molecules at approximately $3_{\frac{1}{2}}$ a and the small domains of the striped structures supporting that the observed surface structures on the annealed surface were the extension of the primitive layer of 2-mercaptoethanol. Comparing these observations with the already published structures of ethanthiol, it was concluded that the interaction between the hydroxyl groups of 2-mercaptoethanol might play a significant role in the adsorption step of 2-mercaptoethanol on Au(111) to organize the adsorption structures different from those of ethanthiol.

• Plant Journal
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• v.13 no.3
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• pp.30-35
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• 2017

Module can be categorized as PAS(Pre-Assembled Steel structure), PAR(Pre-Assembled pipe Rack), PAU(Pre-Assembled Unit), VAU(Vendor Assembled Unit) and VPU(Vendor Package Unit). At the stage of design and fabrication of module, the condition of land and ocean transportation is considered and these conditions are reflected on the module division design. The control of the module's center of gravity is important to transport and install modules safely and the steel structure should have the strength enough to resist the sea acceleration force during the ocean transportation. The transportation condition and the installation method influence the size and weight of module. The size and weight of module are considered for the design of module division.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.121-128
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• 1997

The Boundary Element Method(BEM) has many advantages. Nevertheless the applicability of BEM to structural analysis is seemed to be behind the other methods. This study presents the application of the BEM for analysis of assembled plate structures which is light weight and has a great loading capacity. Firstly, we formulate the boundary integral equation of the single plate, using the biharmonic fundamental solution for plate bending and internal force problems. Nextly, each plates are assembled on 3-dimensional space. In this process, the boundary conditions on assemble line are used. To verify the objectivity and universal validity of analysis by BEM, the results of BEM was compared to that of SAP90 by using FEM.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.191.1-191.1
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• 2014

Crystallization has become the most popular technique for the separation of enantiomers since the Pasteur's discovery. To investigate mechanism of crystallization of chiral molecules, it is necessary to study self-assembled structures on two-dimensional surface. Here, we have studied two-dimensional self-assembled structures of an unnatural amino acid, (S)-${\beta}$-methyl naphthalen-1-${\gamma}$-aminobutyric acid (${\gamma}^2$-1-naphthylalanine) on Au(111) surface at 150 K using scanning tunneling microscopy (STM). At initial stage, we found two chiral honeycomb structures which are counter-clockwise and clockwise configurations in one domain. The molecules are arranged around molecular vacancies, dark hole. By further increasing the amounts of adsorbed ${\gamma}^2$-1-naphthylalanine, a well-ordered square packed structure was observed. In addition, we found the other structure that molecules were trapped in the pore of the hexagonal molecular assembly.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.280-280
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• 2013

Using both experimentaland theoretical methods, we have investigated the structural and electronic properties of self-assembled two-dimensional organic molecule (hexaaza-triphenylene-hexacarbonitrile, HATCN), which is used as an efficient OLED hole injection material, on Au(111) surfaces. Low-temperature scanning tunneling microscope (STM) measurements revealed that self-assembled linear and hexagonal porous structures are formed at atomic steps and terraces of Au(111), respectively. We also found that the hexagonal porous structure have chirality and forms only small (＜1,000 nm2) phase-separated chiral domains that can easily change their chiral phase in subsequence STM images at 80 K. To explain these observations, we calculated the molecular-molecular and molecule-surface interaction energies by using first-principles density functional theory method. We found that the change of their chiral phase resulted from the competition between the two energies. These results have not only verified our experimental observations, but also revealed the delicate balance between different interactions that caused the self-assembed structures at the surface.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.270-270
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• 2013

We have investigated the self-assembled structures of glutaric acid (HOOC-(CH2)3-COOH) on the Cu(110) surface as a function of coverage using Scanning Tunneling Microscopy (STM). At low coverage, glutaric acid molecules diffuse freely on Cu(110) surface at room temperature, thus they can't form ordered structures at this coverage. However, when we scanned the same area several times, novel structures have been created during scanning due to the field-induced self-assembly. Also, the induced structures are quite stable during continuous scanning process. At 0.25 ML, glutaric acid adsorbs as a bi-glutarate (-OOC(CH2)3-COO-) after annealing to 450 K producing a racemic conglomerate of coexisting mirror domains. Although the molecule is achiral, it forms chiral domains on the surface from adsorption-induced asymmetrization. At 0.5 ML coverage, zigzag structure is observed, and still gltutaric acid adsorbs as a bidentate configuration. This bi-glutarate structure is stable until 650. Finally, at 1ML, glutaric acid adsorbs as a mono-glutarate at room temperature forming close packed structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.948-954
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• 2002

The structural vibration of a diesel generator set was investigated through analyses and tests. FE modeling and normal mode analysis were performed and compared with measured results for both structure components and generator set assembly. The results of component analyses were fairly well coincident with measured results but those of assembled generator set showed more or less discrepancies. Discussions were given about the uncertainties for vibration characteristics of component structures and assembled running structures especially concerning their nonlinearities and damping effects. Detailed excitation analysis fellowed by forced response analysis was done from the engine and pressure data to compare with the actual measured vibration. As results the vibration prediction for frame structures of reciprocating internal combustion engine was confirmed reliable to some extent.

• Proceedings of the Korean Fiber Society Conference
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• 1999.10a
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• pp.505-508
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• 1999