1,721,033 research outputs found
Fault-tolerant adaptive wormhole routing in 2D mesh
No full textA fault-tolerant wormhole routing algorithm on mesh-connected processors is proposed. The proposed algorithm is based on the solid fault model and allows the fault polygons to be overlapped. The algorithm compares the position of fault region relative to current channel with the fault direction held of a misrouted message to route around overlapped fault polygons. A node deactivating algorithm to convert non-solid fault region into solid fault region is also proposed. The proposed routing algorithm uses four virtual channels and is deadlock and livelock free
Monotonic moment-curvature relation of an RC beam
No full textA monotonic moment-curvature relation to simulate the non-linear behaviour of reinforced concrete (RC) beams is introduced, and material non-linear analyses of RC beams are carried out on the basis of the introduced model. Instead of the sophisticated layered section approach, which has some limitations in application to large structures with many degrees of freedom, we use the moment-curvature relations of RC sections previously constructed through section analysis. To reduce numerical instability according to the finite-element mesh size used, a relation simulating the tension-softening branch is taken into consideration. With the purpose of removing the imprecision in calculation of ultimate resisting capacity, we include the plastic hinge length in finite-element modelling. In addition, the governing equation describing the bond-slip behaviour in beams is derived. Unlike the present bond elements using double nodes, the proposed model uses beam elements representing the structural response by two nodes at both ends simplifies the finite-element modelling and analytical process, along with effectively describing the bond-slip behaviour Moreover the developed algorithm is reflected in the moment-curvature relation of the RC section. Finally, correlation studies between analytical and experimental results are conducted with the objective of establishing the validity of the proposed algorithms.The financial support of the Korean Science & Engineering
Foundation (KOSEF) through grant no. ROI-
2000-00367 is gratefully acknowledged
The origin of intrinsic stress and its relaxation for SiOF thin films deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition
No full textSiOF films were deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) on Si(100) substrates as a function of both the SiF4/O-2 flow ratio, as well as the Ar flow rate. The formation of Si-O and Si-F bonds was then confirmed using Fourier transform infrared spectroscopy (FTLR), and the residual stress in the SiOF thin films was also measured. While the SiOF thin films deposited in a SiF4/O-2 ECR plasma were in tensile intrinsic stress, the films deposited in a SiF4/O-2/Ar ECR plasma had compressive intrinsic stress. This transition between tensile and compressive stress was interpreted to result from Ar ion bombardment of the growing film. In the cases where films had compressive intrinsic stress, the magnitude of the compressive stress decreased with increasing SiF4/O-2 ratio. The relaxation of the compressive stress for a given Ar flow rate is related to an F- ion related open structure. (C) 2000 Elsevier Science B.V. All rights reserved.This work was fully supported by the Korea Science and Engineering Foundation, project no. 95-0300-15-01-3
Cyclic moment-curvature relation of an RC beam
No full textA hysteretic moment-curvature relation to simulate the behaviour of a reinforced concrete (RC) beam under cyclic loading is introduced in this paper, and the non-linear behaviour of RC beams subjected to flexural cyclic loading is analysed by means of the introduced model. Unlike previous moment curvature models and the layered section approach, the proposed model takes into consideration the bond-slip effect by using the monotonic moment-curvature relation introduced in the companion paper. This model was constructed on the basis of the bond-slip relation and cot-responding equilibrium equation at each nodal point. In addition, unlike linearised hysteretic curves, the rise of curved unloading and reloading branches inferred from the stress-strain relation of steel considering the Bauschinger effect is employed. This gives more exact structural responses, following a correct assessment of the energy-absorbing capacity of a structure at the large deformation stage. The advantages of the proposed model, compared to the layered section approach, may be on the reduction in calculation time and memory space in application to large-frame structures with many degrees of freedom. The modifications of the moment-curvature relation to reflect fixed-end rotation, axial force and pinching effect are also introduced. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.The financial support of the Korean Science of Engineering Foundation (KOSEF) through grant no. ROI-2000-00369 is gratefully acknowledged
Nonlinear analysis of RC beams based on moment-curvature relation
No full textMaterial nonlinear analyses of reinforced concrete (RC) beams considering the tension softening branch and bond slip have been conducted. Instead of adopting the sophisticated layer approach which has some limitations in application to large structures with many degrees of freedom, we have used the moment-curvature relationships of RC sections previously constructed through section analysis. To reduce numerical instability according to the finite element mesh size used, a relation simulating the tension softening branch has been taken into consideration. For the purpose of removing the imprecision in calculation of ultimate resisting capacity, we have included the plastic hinge length in finite element modeling. In addition, governing equations describing the bond-slip behavior in beams have been derived. Unlike the conventional bond elements using double nodes, the proposed model has used beam elements representing the structural response by two nodes at both ends, and has simplified the finite elements modeling and analytical process, besides effectively describing the bond-slip behavior. Moreover, the developed algorithm has been reflected in the moment-curvature relationship of RC section. Finally, correlation studies between analytical and experimental results have been conducted with the objective to establish the validity of the proposed algorithms. (C) 2002 Elsevier Science Ltd. All rights reserved
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