유은종 교수

Abstract In this study, we determine an updated finite element model of a reinforced concrete building—which was damaged from shaking during 1994 Northridge earthquake—using forced‐vibration test data and a novel model‐updating technique. Developed and verified in the companion paper (viz. BVLSrc, Earthquake Eng. Struct. Dyn . 2006; this issue), this iterative technique incorporates novel sensitivity‐based relative constraints to avoid ill conditioning that results from spatial incompleteness of

The nees @UCLA mobile field laboratory was utilized to collect forced and ambient vibration data from a four‐story reinforced concrete (RC) building damaged in the 1994 Northridge earthquake. Both low amplitude broadband and moderate amplitude harmonic excitation were applied using a linear shaker and two eccentric mass shakers, respectively. Floor accelerations, interstory displacements, and column and slab curvature distributions were monitored during the tests using accelerometers, linear var

Abstract In this study, we formulate an improved finite element model‐updating method to address the numerical difficulties associated with ill conditioning and rank deficiency. These complications are frequently encountered model‐updating problems, and occur when the identification of a larger number of physical parameters is attempted than that warranted by the information content of the experimental data. Based on the standard bounded variables least‐squares (BVLS) method, which incorporates

Abstract This paper describes the development and numerical verification of a test method to realistically simulate the seismic structural response of full‐scale buildings. The result is a new field testing procedure referred to as the linear shaker seismic simulation (LSSS) testing method. This test method uses a linear shaker system in which a mass mounted on the structure is commanded a specified acceleration time history, which in turn induces inertial forces in the structure. The inertia fo

In this study, an experimental program was performed on masonry-infilled frame specimens with varied construction precision and masonry thickness. A total of five portal frame specimens, which consist of four masonry-infilled frames and a bare frame, were tested, and the results were analyzed to investigate the effects of construction precision and interaction between the masonry infill and the frame. The test results indicated that the gap in the masonry infill decreased strength by 75% to 80%

Finite element (FE) model updating is a useful tool for global damage detection technique, which identifies the damage of the structure using measured vibration data. This paper presents the application of a finite element model updating method to detect the damage of a small-scale reinforced concrete building structure using measured acceleration data from shaking table tests. An iterative FE model updating strategy using the least-squares solution based on sensitivity of frequency response fun

The nees@UCLA mobile field laboratory was utilized to collect data from forced and ambient vibration testing of a four-story RC building damaged in the 1994 Northridge earthquake. Both low amplitude broadband and moderate amplitude harmonic excitation were applied using a linear shaker and two eccentric mass shakers, respectively, and ambient vibrations were measured before and after each forced vibration test. Accelerations, interstory displacements, and curvature distributions were monitored u

Abstract In this study, an output-based neuro controller was built based on the idea of the adaptive neuro-fuzzy inference system (ANFIS) and its capabilities in response simulation, data cleansing and restoration capability were verified using measurement data from actual structural testing. The ANFIS is a family of the deep learning algorithm, which incorporates the benefits of adaptive control technique, artificial neural network, and the fuzzy inference system. Thus, it is expected to produc

The focus of this study is the application of novel as well as existing methods of modal system identification and finite element model updating techniques to experimental data. The data are collected during a small earthquake and from ambient vibrations. The specimen structure is named the "Louis and Doris Factor Building," and is located at the UCLA campus. It was instrumented by the U.S. Geological Survey with an embedded 72-channel accelerometer network following the 1994 Northridge earthqua

Previous studies on gabled hyperbolic paraboloid shells (gabled hypar) revealed that shell loads are transferred to the supports mainly through diagonal arch action, and the contribution of edge beams, which have been traditionally included based on the assumptions of membrane theory, is actually very limited. This finding introduced a new shape of gabled hypars in which the edge beams are removed. This paper investigated the behaviors of gabled hypars with and without edge beams for various cas