• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.10-21
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• 2007

It is necessary to study about moment performance of glulam-dowel connections which had been applied rotation. To analyze and predict the moment performance, angled to grain load was replaced with parallel to grain load and perpendicular to grain load. The dowel bending strength and dowel bearing strength were tested. And tensile strength test for connections of two different end distances was performed. Specimens of rotation test were composed with different drift pin numbers and drift pin arrangement. Connection deformation was occurred by plastic behavior of drift pin after yield when tensile load applied at connection. And the absorbing drift pin deflection by end distance continued the connection deformation. When rotation applied at connection that 2 drift pins were arranged parallel to grain (b2h), it showed similar performance with tensile perpendicular to grain. And connection that 2 drift pins were arranged perpendicular to grain (b2v) showed similar performance with tensile parallel to grain. Connection capacity that 4 drift pins were arranged rectangular (b4) showed 1.7 times as strong as connection that 2 drift pins were arranged parallel to grain (b2h). These results agreed predicted values and it is available that rotation replaced with tensile load.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.683-692
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• 2011

In piloti-type low-rise RC residential buildings, severe damages have been usually concentrated at piloti stories under the earthquake. In this study, a piloti story was retrofitted by installation of buckling-restrained braces (BRB's) to increase strength and stiffness of piloti story and by application of fiber reinforced polymer (FRP) sheet on columns to avoid the brittle shear and axial failure of columns. To verify this retrofit performance, reversed cyclic lateral load tests were performed on 1:5 scale bare and retrofitted frames. The test results showed that yield strength (43.2 kN) appeared to be significantly larger than design value (30 kN) due to the increase of strength in the compression side, but the stiffness value (11.6 kN/mm) turned out to be approximately one-half of the design value (24.2 kN/mm). The reasons for this difference in stiffness were due to slippage at joint between the frame and the BRB's, displacement and rotation at footing. The energy absorption capacity of the retrofitted frame was 7.5 times larger than that of the bare frame. The change of the number of load cells under the footing from 2 to 1 reduced lateral stiffness from 11.6 kN/mm to 6 kN/mm, which was only three times larger than that of the bare frame (2.1 kN/mm).

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.1
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• pp.25-35
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• 2023

Considering the non-linear behavior of structure and soil when evaluating a nuclear power plant's seismic safety under a beyond-design basis earthquake is essential. In order to obtain the nonlinear response of a nuclear power plant structure, a time-domain SSI analysis method that considers the nonlinearity of soil and structure and the nonlinear Soil-Structure Interaction (SSI) effect is necessary. The Boundary Reaction Method (BRM) is a time-domain SSI analysis method. The BRM can be applied effectively with a Perfectly Matched Layer (PML), which is an effective energy absorbing boundary condition. The BRM has a characteristic that the magnitude of the response in far-field soil increases as the boundary interface of the effective seismic load moves outward. In addition, the PML has poor absorption performance of low-frequency waves. For this reason, the accuracy of the low-frequency response may be degraded when analyzing the combination of the BRM and the PML. In this study, the accuracy of the analysis response was improved by adjusting the PML input parameters to improve this problem. The accuracy of the response was evaluated by using the analysis response using KIESSI-3D, a frequency domain SSI analysis program, as a reference solution. As a result of the analysis applying the optimal PML parameter, the average error rate of the acceleration response spectrum for 9 degrees of freedom of the structure was 3.40%, which was highly similar to the reference result. In addition, time-domain nonlinear SSI analysis was performed with the soil's nonlinearity to show this study's applicability. As a result of nonlinear SSI analysis, plastic deformation was concentrated in the soil around the foundation. The analysis results found that the analysis method combining BRM and PML can be effectively applied to the seismic response analysis of nuclear power plant structures.