• Title/Summary/Keyword: failure mechanisms

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Experimental study on shear behavior of I-girder with concrete-filled tubular flange and corrugated web

  • Shao, Y.B.;Wang, Y.M.
    • Steel and Composite Structures
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    • v.22 no.6
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    • pp.1465-1486
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    • 2016
  • Conventional plate I-girders are sensitive to local buckling of the web when they are subjected mainly to shear action because the slenderness of the web in out-of-plane direction is much bigger. The local buckling of the web can also cause the distorsion of the plate flange under compression as a thin-walled plate has very low torsional stiffness due to its open section. A new I-girder consisted of corrugated web, a concrete-filled rectangular tubular flange under compression and a plate flange under tension is presented to improve its resistance to local buckling of the web and distorsion of the flat plate flange under compression. Experimental tests on a conventional plate I-girder and a new presented I-girder are conducted to study the failure process and the failure mechanisms of the two specimens. Strain developments at some critical positions, load-lateral displacement curves, and load-deflection curves of the two specimens have all be measured and analyzed. Based on these results, the failure mechanisms of the two kinds of I-girders are discussed.

Tensile Fracture Behavior of Glass Fiber/Polypropylene Composites for Various Fiber Volume Fraction (섬유함유율에 따른 GF/PP 복합재료의 인장파괴거동)

  • Koh, Sung-Wi;Um, Yoon-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.2
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    • pp.161-165
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    • 2004
  • The main goal of this work is to study the effect of glass fiber volume fraction on the result of tensile test with respect to glass fiber/polypropylene(GF/PP) composites. The tensile test and failure mechanisms of GF/PP composites were investigated in the fiber volume fraction range from 10% to 30%. The tensile strength and the fracture strength increased with the increasing of the fiber volume fraction in the tested range. Fiber pull-out and debonding of this composites increased with the fiber volume fraction in thc tested range. The major failure mechanisms were classified into the debonding, the fiber pull out, the delamination and the matrix deformation.

An Experimental Study on the Failure Mechanism of Foundation with Depth (근입깊이에 따른 기초지반의 파괴형태에 관한 실험적 연구)

  • Bong, Hyoun Gyu;Lee, Sang Duk;Koo, Ja Kap;Jeon, Mong Gag
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.4
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    • pp.923-932
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    • 1994
  • The studies on the bearing capacity of shallow and deep foundations have been made in various fields and formulas for various failure mechanisms have been presented. But, for these models, the method of classification with foundation depth has been obscure and bearing capacity factors have not been uniformly applied. An experiment was performed, in plane strain conditions, with ground model made of carbon rods. The failure mechanism of foundation and ultimate bearing capacity with foundation depth were observed. Based on experimental results the classification between shallow and deep foundations by failure shape was tried. Various present failure mechanisms of foundation were verified through the experiment.

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Development of Earthquake Resistant Analysis Models for Typical Roadway Bridges (일반도로교의 내진해석모델 개발)

  • 국승규;김판배
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.4
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    • pp.1-6
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    • 2002
  • The structural safety required in general design is to be proved with safety factors provided for structural members in elastic range. But, for the safety requirement in the earthquake resistant design, a specific ductile failure mechanism in plastic range should be verified according to the structural configuration. Therefore such verifications should be done in the preliminary design stage by comparing various design alternatives. In the main design stage only a confirmation of the ductile failure mechanism is required. In this study typical roadway bridges are selected and analysis models are presented for the preliminary and main design. For the two models, vibration periods and mode shapes are compared and the multi-mode spectrum method is applied to determine failure mechanisms. The failure mechanisms obtained with the two models are compared to check the properness of the model used for the preliminary design, which may well be used as an earthquake resistant analysis model in practice.

Detection and Diagnosis Solutions for Fault-Tolerant VSI

  • Cordeiro, Armando;Palma, Joao C.P.;Maia, Jose;Resende, Maia J.
    • Journal of Power Electronics
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    • v.14 no.6
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    • pp.1272-1280
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    • 2014
  • This paper presents solutions for fault detection and diagnosis of two-level, three phase voltage-source inverter (VSI) topologies with IGBT devices. The proposed solutions combine redundant standby VSI structures and contactors (or relays) to improve the fault-tolerant capabilities of power electronics in applications with safety requirements. The suitable combination of these elements gives the inverter the ability to maintain energy processing in the occurrence of several failure modes, including short-circuit in IGBT devices, thus extending its reliability and availability. A survey of previously developed fault-tolerant VSI structures and several aspects of failure modes, detection and isolation mechanisms within VSI is first discussed. Hardware solutions for the protection of power semiconductors with fault detection and diagnosis mechanisms are then proposed to provide conditions to isolate and replace damaged power devices (or branches) in real time. Experimental results from a prototype are included to validate the proposed solutions.

Failure mechanisms of a rigid-perfectly plastic cantilever with elastic deformation at its root subjected to tip pulse loading

  • Wang, B.
    • Structural Engineering and Mechanics
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    • v.2 no.2
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    • pp.141-156
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    • 1994
  • In this paper, the effect of material elasticity was evaluated through a simple model as proposed by Wang and Yu (1991), for yield mechanisms of a cantilever beam under tip pulse loading. The beam was assumed rigid-perfectly plastic but instead of the usual fully clamped constraints at its root, an elastic-perfectly plastic rotational spring was introduced there so the system had a certain capacity to absorb elastic energy. Compared with a rigid-perfectly plastic beam without a spring root, the present beam-spring model showed differences in the initial plastic hinge position and the minimum magnitude of the dynamic force needed to produce a plastic failure. It was also shown that various failure responses may happen while the hinge travels along the beam segment towards the root, rather than a unique response mode as in a rigid perfectly plastic analysis.

Detailing in RC Pier Coping According to the Design Methods (설계방법에 따른 RC 교각 코핑부의 배근상세)

  • Park Kyu Yul;Lee Seung Hun;Eom Jang Sub;Jin Chi Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.217-220
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    • 2005
  • The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The reinforced concrete pier coping consists of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, reinforced concrete pier coping is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. The results show that strut-tie model can be a rational and an economical design than current conventional design methods.

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Slope Stability Analysis Using Continuum/FEM Approaches (유한요소법과 연속체역학을 이용한 사면안정해석)

  • 서영교
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.135-142
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    • 2000
  • A framework alternative to that of classical slope stability analysis is developed, wherein the soil mass is treated as a continuum and in situ soil stresses and strengths are computed accurately using inelastic finite element methods with general constitutive models. Within this framework, two alternative methods of stability analysis are presented. In the first, the strength characteristics of the soil mass are held constant, and the gravitational loading on the slope system is increased until failure is initiated by well-defined mechanisms. In the second approach, the gravity loading on the slope system is held constant, while the strength parameters of the slope mass are gradually decreased until well-defined failure mechanisms developed. Details on the applying both of the proposed methods, and comparisons of their characteristics on a number of solved example problems are presented.

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Detailing in Rectangular Shaped Corbel According to the Design Methods (설계방법에 따른 직사각형 단면 코벨의 배근상세)

  • Kim, Dae-Seong;Kim, Tae-Wan;Lee, Seung-Hun;Eom, Jang-Sub;Jin, Chi-Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.373-376
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    • 2004
  • The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The rectangular shaped corbel consist of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, rectangular shaped corbel is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. The results show that strut-tie model can be a rational and an economical design than current conventional design methods.

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Detailing in the Pi(${\pi}$)-Shaped RC Rahmen Bridge According to the Design Methods (설계방법에 따른 ${\pi}$형 RC 라멘교의 배근상세)

  • We, Jeung-Bok;Lee, Seung-Hun;Eom, Jang-Sub;Jin, Chi-Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.213-216
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    • 2006
  • The designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of D-region. The reinforced concrete pi(${\pi}$)-shaped RC rahmen bridge consists of various failure mechanisms as the crushing or splitting from compression concrete, and shearing failure under the loading plate. However, predicting those failure mechanisms is very difficult. In this study, the pi(${\pi}$)-shaped RC rahmen bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice. As a result that designing the structures should be maked a comparison between strut-tie model and current conventional design method.

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