The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

Phuong Tran - One of the best experts on this subject based on the ideXlab platform.

  • hybrid Mesh modelling validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

  • Hybrid-Mesh modelling & validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

Eric Yang - One of the best experts on this subject based on the ideXlab platform.

  • hybrid Mesh modelling validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

  • Hybrid-Mesh modelling & validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

Steven Linforth - One of the best experts on this subject based on the ideXlab platform.

  • hybrid Mesh modelling validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

  • Hybrid-Mesh modelling & validation of woven Fabric subjected to medium velocity impact
    International Journal of Mechanical Sciences, 2018
    Co-Authors: Eric Yang, Steven Linforth, Phuong Tran
    Abstract:

    Abstract Simulation of the ballistic impact on a woven Fabric structure is known to be difficult due to their warp-weft yarn interlacing geometry, the varying cross-section of a yarn along its length, the multi-layer and direction of the Fabric, and the contact between individual yarns. To account for the complex geometry and contact behaviour, Fabric structures were modelled with meso‑scale (yarn level) geometrical details, which demanded a substantial amount of computational resources. In this research, a hybrid-Mesh finite element modelling approach that possesses greater computational efficiency has been developed to simulate the behaviour of multi-layer woven Fabrics subjected to medium velocity impact. Yarn models are developed using different Mesh sizes: four, six, eight, and twelve solid elements per cross-section with one and two layer Mesh arrangements. They are then used to create hybrid-Mesh Fabric models, in which the finest Mesh yarns are placed at the impact centre, and gradually decreasing Mesh densities are used towards the Fabric boundaries. The FE results, including deformation, stress distribution, and wave propagation, are evaluated. The simulation indicated a significant reduction in computational resources while maintaining the necessary accuracy.

E. Leonardi - One of the best experts on this subject based on the ideXlab platform.

  • Deadlock-free routing in an optical interconnect for high-speed wormhole routing networks
    Proceedings of 1996 International Conference on Parallel and Distributed Systems, 1996
    Co-Authors: P. Palnati, M. Gerla, E. Leonardi
    Abstract:

    The Supercomputer SuperNet (SSN) is a two-level hierarchical high-speed network. The lower level is a high speed electronic Mesh Fabric; the higher level is a WDM optical backbone network interconnecting the high-speed Fabrics distributed across a campus or metropolitan area. The salient characteristics of this architecture are the use of wormhole routing and backpressure hop-by-hop flow control mechanism. Because of these features, deadlocks are possible in SSN. In this paper, we address the issue of deadlock-free routing which is an essential prerequisite for the proper operation of SSN. To this end, we first present a deadlock free routing scheme for the WDM backbone which is implemented with a shufflenet multihop virtual topology. We use the notion of virtual channels to obtain mappings of virtual channels to physical channels such that deadlock-free routing is achieved for any (p,k) shufflenet (uni and bidirectional). Then, we compare the virtual channels scheme with the more conventional up/down deadlock free routing scheme for the bidirectional shufflenet and show that the former yields much better performance. Finally, we address the problem of deadlock prevention across the entire network (i.e., lower level Fabric as well as the optical backbone) and develop an integrated solution combining different schemes best suited for the different levels.

  • ICPADS - Deadlock-free routing in an optical interconnect for high-speed wormhole routing networks
    Proceedings of 1996 International Conference on Parallel and Distributed Systems, 1996
    Co-Authors: P. Palnati, M. Gerla, E. Leonardi
    Abstract:

    The Supercomputer SuperNet (SSN) is a two-level hierarchical high-speed network. The lower level is a high speed electronic Mesh Fabric; the higher level is a WDM optical backbone network interconnecting the high-speed Fabrics distributed across a campus or metropolitan area. The salient characteristics of this architecture are the use of wormhole routing and backpressure hop-by-hop flow control mechanism. Because of these features, deadlocks are possible in SSN. In this paper, we address the issue of deadlock-free routing which is an essential prerequisite for the proper operation of SSN. To this end, we first present a deadlock free routing scheme for the WDM backbone which is implemented with a shufflenet multihop virtual topology. We use the notion of virtual channels to obtain mappings of virtual channels to physical channels such that deadlock-free routing is achieved for any (p,k) shufflenet (uni and bidirectional). Then, we compare the virtual channels scheme with the more conventional up/down deadlock free routing scheme for the bidirectional shufflenet and show that the former yields much better performance. Finally, we address the problem of deadlock prevention across the entire network (i.e., lower level Fabric as well as the optical backbone) and develop an integrated solution combining different schemes best suited for the different levels.

Alberto Franchi - One of the best experts on this subject based on the ideXlab platform.

  • Optimisation of ductility of welded steel bars, ribbed coils and Mesh Fabric for reinforced concrete elements under severe seismic loads
    Europace, 2020
    Co-Authors: Alberto Franchi, R. Santoro, G. Demofonti, P. Michelis, M. Pipa, M. Gomes, L. Bianco
    Abstract:

    Major open problems concerning steel reinforcement, recognised at the international level in the technical and scientific literature, are addressed in the present research report and shortly listed and commented with the obtained results in the following. Ductility, intended both as ultimate to yield stress ratio and deformation at ultimate monotonic loading, is too low in several reinforcing products available on the European production. A set of parallel experimental tests performed by various independent laboratories have allowed to identify mechanical properties of the skin and of the core of the rebar product as a function of the carbon content and of the equalisation temperature. An analytical model has been formulated, implemented and validated for the prediction of strength and ductility parameters under monotonic loading as a function of carbon content and equalisation temperature, allowing for the different diameters and rib geometry. A finite element model of the ribbed bar in the elastic-plastic finite deformation range, conceived as a skin, an intermediate zone and a core, has been conceived, implemented and validated with comparison to the experimental results; it has allowed to better understand the local mutual influence of various zones with different material properties, and evaluate the stress concentration due to the rib geometry. An optimised steel rebar, in terms of carbon content and equalisation temperature, has been formulated for a given yield stress of 450 MPa and optimising the ductility parameters. An optimised steel wire, in terms of carbon content and stretch amount, has been formulated for the same purposes as explained above for the rebar product. Energy dissipation during low cycle fatigue tests is to be increased, in order to meet the requirements and expectations of reinforced concrete structure designers, especially in seismic areas, where the kinetic energy transferred to the structure by the grounds motion has to be dissipated in the so called "plastic hinge" essentially by the steel reinforcement. An extensive testing program, involving different independent laboratories, has been completed for rebar, stretched wire and welded joints under cyclic loading condition. The failure mechanism has been observed clearly, and confirmed by all investigators. Major important variables have been identified in the geometrical differences, imprecision and possible defects. In particular, rib geometry has been proved to be an essential aspect; more precisely the radius of curvature of the interaction of the rib surface with the cylindrical external surface of the bar has been observed to be critical. Special attention is to be paid to the welding procedures inside the "plastic hinge", where now welding is forbidden but significant improvements have to be expected if proper and industrially controlled welding procedures are studied and then standardised. Welding techniques have been studied extensively in the past with respect to the monotonic loading; almost nil has been done on these products in terms of cyclic loading. A set of experiments has been conceived, implemented and discussed on welded cruciform joints, demonstrating the technical capability to reach a joint which does not decrease the original mechanical properties of the parent materials, both in terms of strength and ductility.

  • Behavior of Reinforced Concrete Walls with Welded Wire Mesh Subjected to Cyclic Loading
    Aci Structural Journal, 2001
    Co-Authors: Paolo Riva, Alberto Franchi
    Abstract:

    This paper presents the results from an experimental research project on 18 cantilever walls subjected to in-plane cyclic loading. The primary aim was to determine whether welded wire Mesh Fabric could provide sufficient ductility for seismic applications. The tests indicate that walls reinforced by means of hot-rolled Mesh exhibit ductility properties comparable to those reinforced with ordinary reinforcement only. Traditional cold-drawn Mesh Fabric proved to be unsuitable for seismic uses.