• Title/Summary/Keyword: Collapse modes

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Modes of Innovation and the National Systems of Innovation of the BRICS Economies

  • Scerri, Mario
    • STI Policy Review
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    • v.5 no.2
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    • pp.20-42
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    • 2014
  • The Brazil, Russia, India China and South Africa (BRICS) group has emerged as a collection of large economies which are outside the traditional groups of industrialised "first world" economies and which have altered the global distribution of economic power. The basis of their emergence is a combination of their size and growth rates, and the fact that they lie outside the established centres of global economic power. As such, they have "diversified" the power base of the global economic order. The question which is asked in this paper is whether the phenomenon of the BRICS goes beyond this to mark the start of a possible challenge to the neoliberal orthodoxy which emerged as the globally dominant policy paradigm since the collapse of the Soviet Union. This paper develops and uses a "modes of innovation" approach to explore the potential of the BRICS to constitute a structural rupture in the current globally dominant neoliberal mode of innovation. This question is important since, in the absence of this rupture, the remarkable development trajectory of the BRICS will serve to reinforce the legitimacy of the global orthodoxy. The paper first articulates the modes of innovation concept and then proceeds to locate the BRICS systems of innovation within the current globally dominant mode. On this basis it then provides an appraisal of the possible impact of the BRICS on the evolutionary path of the global system of innovation.

Collapse-resistant performance of a single-story frame assembly and multi-story sub-frame under an internal column-removal scenario

  • Zhong, Wei-hui;Tan, Zheng;Tian, Li-min;Meng, Bao;Zheng, Yu-hui;Daun, Shi-chao
    • Steel and Composite Structures
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    • v.41 no.5
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    • pp.663-679
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    • 2021
  • To elucidate the differences in the collapse behavior between a single-story beam-column assembly and multi-story frame, two 1/3-scale two-bay composite frames, including a single-story composite beam-column assembly and a three-story composite sub-frame, were designed and quasi-statically tested. The load-displacement responses, failure modes, and internal force development of the two frames were analyzed and compared in detail. Furthermore, the resistance mechanisms of the two specimens were explored, and the respective contributions of different load-resisting mechanisms to the total resistances were quantitatively separated to gain deeper insights. The experimental tests indicated that Vierendeel action was present in the two-dimensional multi-story frames, which led to an uneven internal force distribution among the three stories. The collapse resistance of TSDWA-3S in the flexural stage was not significantly increased by the structural redundancy provided by the additional story, as compared to that of TSDWA-1S. Although the development of the load response was similar in the two specimens at flexural stage, the collapse mechanisms of the multi-story composite frame were much more complicated than those of the single-story beam-column assembly, and the combined action between stories was critical in determining the internal force redistribution and rebalancing of the remaining structure.

Energy Absorption Characteristics of the Al/CFRP/GFRP Hybrid Member under Quasi-static Axial Compressive Load (준정적 축 압축하중을 받는 Al/CFRP/GFRP 혼성부재의 에너지흡수 특성)

  • Kim, Sun-Kyu;Heo, Uk;Im, Kwang-Hee;Jung, Jong-An
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.4
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    • pp.588-592
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    • 2012
  • This study concentrates the effect of hybridisation on the collapse mode and energy absorption for composite cylinders. The static collapse behavior of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell under quasi-static axial compressive load has been investigated experimentally. Eight different hybrids of laminated(Al/CFRP/GFRP) circular-cylindrical composite shell were fabricated by autoclave. Eight types of composites were tested, namely, Al/carbon fiber/epoxy, Al/glass fiber/epoxy, Al/carbon-carbon-glass/epoxy, Al/carbon-glass-carbon/epoxy, Al/carbon-glass-glass/epoxy, Al/glass-glass-carbon/epoxy, Al/glass-carbon-glass/epoxy and Al/glass-carbon-carbon/epoxy. Collpase modes were highly dominated by the effect of hybridisation. The results also showed that the hybrid member with material sequence of Al-glass-carbon-carbon/epoxy exhibited good energy absorption capability.

Structural identification and seismic performance of brick chimneys, Tokoname, Japan

  • Aoki, T.;Sabia, D.
    • Structural Engineering and Mechanics
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    • v.21 no.5
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    • pp.553-570
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    • 2005
  • Dynamic and static analyses of existing structures are very important to obtain reliable information relating to actual structural properties. For this purpose a series of material test, dynamic test and static collapse test of the existing two brick chimneys, in Tokoname, are carried out. From the material tests, Young's modulus and compressive strength of the brick used for these chimneys are estimated to be 3200 MPa and 7.5 MPa, respectively. The results of static collapse test of the existing two brick chimneys are discussed in this paper and composed with the results from FEA (Finite Element analysis). From the results of dynamic tests, the fundamental frequencies of Howa and Iwata brick chimneys are estimated to be about 2.69 Hz and 2.93 Hz, respectively. Their natural modes are identified by ARMAV (Autoregressive Moving Average Vectors) model. On the basis of the static and dynamic experimental tests, a numerical model has been prepared. According to the European code (Eurocode n. 8: "Design of structures for earthquake resistance") non-linear static (Pushover) analysis of the two chimneys is carried out and they seem to be vulnerable to earthquakes with 0.25 to 0.35 g.

Crush FE Analysis of Front Side Assembly of Passenger Cars for Identifying the Roles of Major Parts Influencing on Collapse Mode with Reverse Engineering (승용차 프론트 사이드 조립체 부품의 역할과 붕괴모드에 관한 역설계적 유한요소 충돌해석)

  • Kim, Yong-Woo;Kim, Jeong-Ho;Jeong, Kyung-Shin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.4
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    • pp.33-40
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    • 2007
  • Crashworthiness design is of special interest in automotive industry and in the transportation safety field to ensure the vehicle structural integrity and more importantly the occupant safety in the event of the crash. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on auto-makers and size of vehicles. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of passenger cars to identify the mechanical roles of major parts in relation to collapse modes from the viewpoint of reverse engineering. To do this, we have performed crash FE analysis for the two different assemblies of small car and heavy passenger car and have compared dynamic behaviors of the two.

Nonlinear Buckling Characteristics of Ring-stiffened Circular Cylinders under Uniform External Pressure (균일한 외압을 받는 원환보강 원통구조의 비선형 좌굴 특성)

  • Ahn, Dang;Kim, Soo-Young;Shin, Sung-Chul;Chung, Bo-Young;Koo, Youn-Hoe
    • Journal of Ocean Engineering and Technology
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    • v.26 no.2
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    • pp.79-84
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    • 2012
  • This study aimed to analyze the nonlinear buckling of ring-stiffened circular cylinders under uniform external pressure, e.g. hydrostatic pressure, considering material nonlinearity and initial imperfection. In the present study, we analyzed the collapse pressure of pressure vessels using ANSYS Workbench, which is a framework of finite element methods. First, linear buckling analysis is performed to find collapse modes of the model. Second, scaling the first mode shape with small factor, geometric model is pre-deformed. And then, by analyzing the nonlinear buckling of the pre-deformed shape, the collapse pressure is estimated. To verify the validity of the analyses, we compared the results with Ross' experimental results. Finally, we applied it to ring-stiffened circular cylindrical shell of the pressure hull of a small submarine.

An Experimental Study on Deep Collapse of Steel Tubes under Pure Bending (순수 굽힘 시험기를 이용한 연강 사각관의 굽힘 붕괴에 관한 실험적 연구)

  • KiM, C.S.;Chung, T.E.;Kang, S.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.9
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    • pp.37-44
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    • 1997
  • In this paper the bending collapse characteristics of square and rectangular steel tubes were studied with the pure bending test machine which apply pure bending moment without imposing shear and tensile forces. Under pure bending moment, delayed buckling modes occur and depend on test length and shape of section. For delayed mode, the endrgy of bending moment is absorbed by strain hardening energy. The pre- dictions of maximum moment and moment-rotation angle curve from those concepts are in good agreement with experimental observations.

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Topology Optimization of Structures in Plastic Deformation using Finite Element Limit Analysis (유한요소 극한해석을 이용한 소성변형에서의 구조물의 위상최적화)

  • Lee, Jong-Sup;Huh, Hoon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.603-608
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    • 2008
  • It is well known that the topology optimization for plastic problem is not easy since the iterative analyses to evaluate the objective and cost function with respect to the design variation are very time-consuming. The finite element limit analysis is an efficient tool which is possible to predict collapse modes and sequential collapse loads of a structure considering not only large deformation but also plastic material behavior with moderate computing cost. In this paper, the optimum topology of a structure considering large and plastic deformation is obtained using the finite element limit analysis. To verify the constructed optimization code, topology optimizations of some typical problems are performed and the optimal topologies by elastic design and plastic design are compared.

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Metal Ion-Containing Langmuir-Blodgett Films of a Monooctadecyl Itaconate Copolymer

  • 손종현;최기선;이범종;Kazue Kurihara
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.316-320
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    • 1995
  • The incorporation of metal ion into the Langmuir-Blodgett (LB) film of an itaconate copolymer was investigated. The polymer was prepared via radical copolymerization of monooctadecyl itaconate with triethyleneglycol methyl vinyl ether. The metal ions employed were Na+, Cs+, Mg2+, Fe2+, Al3+, and Fe3+. The surface pressure-area isotherms indicated that all the monolayers studied on subphases with metal ions showed more expanded areas than that observed on pure water. The monolayers showed an irreversible collapse behavior. The collapse pressure of the monolayers was low on subphases containing trivalent metal ions. From the FT-IR spectra by reflection and transmission modes, the formation of carboxylate salts and the uprisen orientation of the pendant against substrate surface in the polymer LB film were determined. It was estimated by XPS measurement that ca. 13.1 repeat units of the polymer contain one Na+ ion, while one Mg2+ ion corresponds to 5.9 carboxyls.

Neural network based modeling of infilled steel frames

  • Subramanian, K.;Mini, K.M.;Josephine Kelvina Florence, S.
    • Structural Engineering and Mechanics
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    • v.21 no.5
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    • pp.495-506
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    • 2005
  • A neural network based model is developed for the structural analysis of masonry infilled steel frames, which can account for the non-linearities in the material properties and structural behaviour. Using the data available from the analytical methods, an ANN model with input parameters consisting of dimension of frame, size of infill, properties of steel and infill was developed. It was found to be acceptable in predicting the failure modes of infilled frames and corresponding failure load subject to limitations in the training data and the predicted results are tested using the available experimental results. The study shows the importance of validating the ANN models in simulating structural behaviour especially when the data are limited. The ANN model was also compared with the available experimental results and was found to perform well.