• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.373-376
• /
• 2006

There are representative two performance evaluation methods for performance-based design(PBD) of reinforced concrete structures by the nonlinear static analysis, one method includes the capacity spectrum method(CSM) suggested in ATC-40(996) and the other is the displacement coefficient method(DCM) in FEMA-273(1997). The objective of this paper is to compare and verify two methods and suggest the displacement-based design for new performance evaluation of reinforced concrete structures.

• Geomechanics and Engineering
• /
• v.15 no.4
• /
• pp.947-955
• /
• 2018

In this study, we propose a three-dimensional simplified slope stability analysis using a hybrid-type penalty method (HPM). In this method, a solid element obtained by the HPM is applied to a column that divides the slope into a lattice. Therefore, it can obtain a safety factor in the same way as simplified methods on the slip surface. Furthermore, it can obtain results (displacement and strain) that cannot be obtained by conventional limit equilibrium methods such as the Hovland method. The continuity condition of displacement between adjacent columns and between elements for each depth is considered to incorporate a penalty function and the relative displacement. For a slip surface between the bottom surface and the boundary condition to express the slip of slope, we introduce a penalty function based on the Mohr-Coulomb failure criterion. To compute the state of the slip surface, an r-min method is used in the load incremental method. Using the result of the simple three-dimensional slope stability analysis, we obtain a safety factor that is the same as the conventional method. Furthermore, the movement of the slope was calculated quantitatively and qualitatively because the displacement and strain of each element are obtained.

• Journal of Korean Association for Spatial Structures
• /
• v.13 no.1
• /
• pp.69-77
• /
• 2013

This study is the research appling the representative Displacement-Based Design which is the basic concept of Direct Displacement Based Design proposed by Chopra and Goel to original Reinforced Concrete moment frame and determining the thickness of retrofit Steel Jacket about the Maximum design ground acceleration, and developing the more improved Algorithm as well as program by the Retrofit Design method and Nonlinear analysis by the Performance design method before and after reinforcement appling the determined retrofit thickness. It also shows the result of the seismic performance improvement which is the ratio of seismic performance appreciation result yield displacement 19%, yield strength ratio 24%, displace ductility ratio the maximum 27% comparing Multi degree of freedom, column member of Reinforced Concrete with the performance improvement column member considering the thickness of the determined Steel Jacket. The developed Algorithm and program are easy to apply seismic design and application to the original Reinforced Concrete building, at the same time, it applicate to display well the design result of Target displacement performance level about nonlinear behavior.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.6
• /
• pp.1030-1035
• /
• 1992

This paper presents a non-contact type displacement sensor designed based on optical triangulation method. The optical principles of the sensor are described in detail with aids of paraxial geometric optics. A prototype sensor is designed and fabricated by using modern optoelectronic hardware. Its measuring performances are evaluated and discussed through a series of calibration processes.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.59-60
• /
• 2021

To measure the effect of the stress-strain dispersion across the installed waterproofing layer on the concrete surface, a strain gauge was attached to the gap between the waterproofing layer and the concrete structure at specified points of upper, center and bottom of the load-displacement simulation specimen, and the peak stress-strain at the displacement interface were measured and compared with stress-strain at other areas to analyze each material types' stress-strain dispersion ratio properties. Based on the results of the testing, it was shown that materials with high load-displacement resistance performance accordingly had high stress-strain dispersion ratio results, and the materials from highest performance to lowest performance were; CAS, SAS, PUC and CSC.

• Geophysics and Geophysical Exploration
• /
• v.6 no.2
• /
• pp.77-86
• /
• 2003

We designed a new time-domain, finite-difference, elastic wave modeling technique, based on a displacement formulation. which yields nearly correct solutions to Lamb's problem. Unlike the conventional, displacement-based, finite-difference method using a node-based grid set (where both displacements and material properties such as density and Lame constants are assigned to nodal points), in our new finite-difference method, we use a cell-based grid set (where displacements are still defined at nodal points but material properties within cells). In the case of using the cell-based grid set, stress-free conditions at the free surface are naturally described by the changes in the material properties without any additional free-surface boundary condition. Through numerical tests, we confirmed that the new second-order finite differences formulated in the cell-based grid let generate numerical solutions compatible with analytic solutions unlike the old second-order finite-differences formulated in the node-based grid set.

• Journal of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.491-497
• /
• 2007

In the current research, the scheme of displacement-based seismic design for seismic retrofit of concrete structures using FRP composite materials has been proposed. An algorithm of the nonlinear flexural analysis of FRP composite concrete members has been presented under multiaxial constitutive laws of concrete and composite materials. An algorithm for performance-based seismic retrofit design of reinforced concrete columns with FRP jacket has been newly introduced to modify the displacement coefficient method used in reinforced concrete structures. From applications of retrofit design, the method are easy to apply in the practice of retrofit design and give practical prediction of nonlinear seismic performance evaluation of retrofitted structures.

• Structural Monitoring and Maintenance
• /
• v.5 no.1
• /
• pp.129-150
• /
• 2018

This paper presents the structural performance monitoring of an urban footbridge located in Hangzhou, China. The structural health monitoring (SHM) system is designed and implemented for the footbridge to monitor the structural responses of the footbridge and to ensure the structural safety during the period of operation. The monitoring data of stress and displacement measured by the fiber Bragg grating (FBG)-based sensors installed at the critical locations are used to analyze and assess the operation performance of the footbridge. A linear regression method is applied to separate the temperature effect from the stress monitoring data measured by the FBG-based strain sensors. In addition, the static vertical displacement of the footbridge measured by the FBG-based hydrostatic level gauges are presented and compared with the dynamic displacement remotely measured by a machine vision-based measurement system. Based on the examination of the monitored stress and displacement data, the structural safety evaluation is executed in combination with the defined condition index.

• Journal of Korean Association for Spatial Structures
• /
• v.12 no.4
• /
• pp.99-108
• /
• 2012

In recently, sky-bridge are often applied to high-rised adjacent buildings for pedestrian bridge. the seisnic response control of adjacent buildings have been studied and magneto-rheological(MR) fluid dampers have been applied to seismic response control. In this study, vibration control effect of the MR damper connected adjacent buildings has been investigated. Adjacent building structures with different natural frequencies were used as example structures. Two typed of control methods, displacement based or velocity based, are applied to determinate control force of MR damper. In this numerical analysis, it has been shown that displacement-based control algorithm is more effective than velocity-based control algorithm for seismic response control of adjacent buildings. And, when displacement-based control method is applied to control of adjacent buildings, the control of building occurred large displacement is more efficient in reducing the seismic response.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.6 no.2
• /
• pp.1-7
• /
• 2002

A procedure for determination of performance point was developed based on the concept of the direct displacement-based design method. Using the proposed procedure, parametric study has been performed for various natural periods of the structure, yield strength, and the stiffness after the first yield. The proposed method was also applied to a 10-story steel frame, and the results were compared to those from the capacity spectrum method and the time history analysis. It was found from the comparison that there were good agreement between the results.