• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.91-92
• /
• 2009

This paper presents an experimental investigation of seismic performance of cast-in-place concrete filled FRP tube in which the FRP is used for concrete form and lateral confinement.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.211-217
• /
• 2006

This analysis evaluated small and large temperature gradient effects on the FRP deck considering lightweight of FRP deck and ply orientations at the interface between steel girders and FRP deck. Finally, the analytical results shows the possible failure mechanism of FRP deck under various temperature changes and its corresponding index is suddenly varied depending on the rapid change of temperature on the deck plate.

• The magazine of the Korean Society for Advanced Composite Structures
• /
• v.3 no.2
• /
• pp.20-24
• /
• 2012

• Computational Structural Engineering
• /
• v.20 no.1 s.75
• /
• pp.71-77
• /
• 2007

• The magazine of the Korean Society for Advanced Composite Structures
• /
• v.2 no.3
• /
• pp.26-32
• /
• 2011

• Coupled systems mechanics
• /
• v.9 no.4
• /
• pp.359-379
• /
• 2020

Due to susceptibility of bridges in the past earthquakes, vulnerability assessment and strengthening of bridges has gained a particular significance. The objective of the present study is to employ an analytical method for the development of fragility curves, as well as to investigate the effect of strengthening on the RC box-girder bridges. Since fragility curves are used for pre-and post-earthquake planning, this paper has attempted to adopt the most reliable modeling assumptions in order to increase the reliability. Furthermore, to acknowledge the interaction of soil, abutment and pile, the effect of different strengthening methods, such as using steel jacketing and FRP layers, the effect of increase in the bridge pier diameter, and the effect of vertical component of earthquake on the vulnerability of bridges in this study, a three-span RC box-girder bridge was modeled in 9 different cases. Nonlinear dynamic analyses were carried out on the studied bridges subjected to 100 ground motion records via OpenSEES platform. Therefore, the fragility curves were plotted and compared in the four damage states. The results revealed that once the interaction of soil and abutment and the vertical component of the earthquake are accounted for in the calculations, the median fragility is reduced, implying that the bridge becomes more vulnerable. It was also confirmed that steel jackets and FRP layers are suitable methods for pier strengthening which reduces the vulnerability of the bridge.

• Journal of Mechanical Science and Technology
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2003

This paper summarizes the results of the fatigue test of four composite bridge decks in extreme temperatures (-30$^{\circ}C$ and 50$^{\circ}C$ ). The work was performed as part of a research program to evaluate and install multiple FRP bridge deck systems in Dayton, Ohio. A two-span continuous concrete deck was also built on three steel girders for the benchmark tests. Simulated wheel loads were applied simultaneously at two points by two servo-controlled hydraulic actuators specially designed and fabricated to perform under extreme temperatures. Each deck was initially subjected to one million wheel load cycles at low temperature and another one million cycles at high temperature. The results presented in this paper correspond to the fatigue response of each deck for four million load cycles at low temperature and another four million cycles at high temperature. Thus, the deck was subjected to a total of ten million cycles. Quasi-static load-deflection and load-strain responses were determined at predetermined fatigue cycle levels. Except for the progressive reduction in stiffness, no significant distress was observed in any of the composite deck prototypes during ten million load cycles. The effects of extreme temperatures and accumulated load cycles on the load-deflection and load-strain response of FRP composite and FRP-concrete hybrid bridge decks are discussed based on the experimental results.

• Steel and Composite Structures
• /
• v.23 no.2
• /
• pp.205-215
• /
• 2017

The use of advanced fibre composite materials in bridge engineering offers alternative solutions to structural problems compared to traditional construction materials. Advanced composite or fibre reinforced polymer (FRP) materials have high strength to weight ratios, which can be especially beneficial where dead load or material handling considerations govern a design. However, the reduced weight and stiffness of FRP footbridges results in generally poorer dynamic performance, and vibration serviceability is likely to govern their design to avoid the footbridge being "too lively". This study investigates the dynamic behaviour of the 51.3 m span Wilcott FRP suspension footbridge. The assessment is performed through a combination of field testing and finite element analysis, and the measured performance of the bridge is being used to calibrate the model through an updating procedure. The resulting updated model allowed detailed interpretation of the results. It showed that non-structural members such as the parapets can influence the dynamic behaviour of slender, lightweight footbridges, and consequently their contribution must be included during the dynamic assessment of a structure. The test data showed that the FRP footbridge is prone to pedestrian induced vibrations, although the measured response levels were lower than limits specified in relevant standards.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2009.04a
• /
• pp.209-212
• /
• 2009

최근 국내에서 적용되고 있는 콘크리트 충진 FRP 스트럿은 시공성 및 경제성 면에서 매우 뛰어난 공법으로 주목 받고 있으나 그 설계 및 시공에 있어 아직도 불확실한 요소를 내포하고 있다. 특히 최근에는 PSC 박스 거더교에서 교폭을 늘리고 자중을 줄이기 위해 콘크리트 충진 FRP 스트럿을 설치하는 공법이 다수 시공되고 있다. 본 연구에서는 이러한 대상교량에 대해 현장시험을 실시하여 교량시스템에서의 콘크리트 충진 FRP 스트럿 거동을 분석하는데 목적이 있다. 특히 전자기파 간섭에 면역이 우수한 광센서인 FBG 센서를 기반으로 하는 계측을 실시하여 잡음이 없는 우수한 결과를 성공적으로 획득하였다. 그 결과 FRP 스트럿은 하중 재하 위치와 속도에 관계없이 압축응력 상태에 존재하고 있으며 횡방향 거동에 지배되고 있음을 확인하였다.

• Structural Engineering and Mechanics
• /
• v.84 no.1
• /
• pp.101-111
• /
• 2022

It is widely known that axially loaded fiber-reinforced polymer (FRP) confined concrete presents significant and enhanced mechanical properties with reference to the unconfined concrete. Therefore, to predict the mechanical behavior of FRP-confined concrete two quantities-peak strength and ultimate strain are required. Despite the significant advances, the determination of the ultimate strain of FRP-confined concrete is one of the most challenging problems to be resolved. This is often attributed to our persistence in desiring the conventional methods as the sole technique to examine this phenomenon and the complex nature of the ultimate strain of FRP-confined concrete. To bridge the research gap, this study adopted two machine learning (ML) techniques-artificial neural network (ANN) and Gaussian process regression (GPR)-to analyze observations obtained from 627 datasets of FRP-confined concrete circular and non-circular sections under axial loading test. Besides, the techniques are also used to predict the ultimate strain of FRP-confined concrete. Seven parameters namely width/diameter of the specimens, corner radius ratio, the strength of concrete, FRP elastic modulus, FRP thickness, FRP tensile rupture strain, and the axial strain of unconfined concrete-are the input parameters used to predict the ultimate strain of FRP-confined concrete. The results of the current study highlight the merit of using AI techniques in structural engineering applications given their extraordinary ability to comprehend multidimensional phenomena of FRP-confined concrete structures with ease, low computational cost, and high performance over the existing empirical models.