The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Kim J.r. Rasmussen - One of the best experts on this subject based on the ideXlab platform.

  • Influence of pallets on the behaviour and design of steel drive-in racks
    Journal of Constructional Steel Research, 2014
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    This paper analyses the influence of horizontal bracing restraints provided by the friction between pallet bases and rail beams on the static behaviour and design of steel drive-in storage racks. The pallet bracing restraints are shown to significantly influence the structural behaviour of the rack, and their effect on the Bending Moment Distribution of the uprights is studied in the paper. The 2D single upright model proposed by Godley is improved in this study by including the restraints provided by the plan flexural stiffness of the rail beams and the friction between the pallets and rail beams. The improved 2D model was found to accurately reproduce the Bending Moment Distributions obtained using 3D advanced finite element analysis. The 2D single upright model is used to analyse 36 drive-in racks under various load case combinations. The paper evaluates the influence of the pallet bracing restraints on the ultimate capacity of drive-in racks, clarifies the loading pattern(s) governing the structural design and determines the friction coefficient, or strength of a restraining device, required to prevent the pallets from sliding. It is shown that while restraints from pallets could potentially be considered in design, they would not lead to more economic structural solutions.

  • Determination of the influence of the pallets on the design of drive-in steel storage racks
    2013
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    This research report analyses the influence of horizontal bracing restraints provided by the friction between pallet bases and rail beams on the static behaviour and design of steel drive-in storage racks. The pallet bracing restraints are shown to significantly influence the structural behaviour of the rack, and their effect on the Bending Moment Distribution of the uprights is studied in the research report. The 2D single upright model proposed by Godley is improved in this study by including the restraints provided by the plan flexural stiffness of the rail beams and the friction between the pallets and rail beams. The improved 2D model was found to accurately reproduce the Bending Moment Distributions obtained using 3D advanced finite element analysis. The 2D single upright model is used to analyse 36 drive-in racks under various load case combinations. The research report evaluates the influence of the pallet bracing restraints on the ultimate capacity of drive-in racks, clarifies the loading pattern(s) governing the structural design and determines the friction coefficient, or strength of a restraining device, required to prevent the pallets from sliding. It is shown that while restraints from pallets could potentially be considered in design, they would not lead to more economic structural solutions.

  • The influence of pallets on the behaviour and design of drive-in steel storage racks - Part I: Behaviour
    2013
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    Drive-in steel storage racks represent a popular alternative to the more common selective racks when available space is restricted or when storing the same good. In drive-in racks, the forklift truck drives into the rack and stores the pallets on beam rails on the "first-in last-out" principle. Recent experimental studies have shown that by acting as horizontal ties between uprights, pallets significantly influence the structural behaviour of the rack. However, due to the uncertainty in the degree of friction between the rail beams and the pallets, current industry design practice does not consider this effect. This paper quantifies the influence of the pallets on the Bending Moment Distribution in the uprights using a 3D finite element model calibrated against experimental results on a full scale drive-in rack. Additionally, as 3D models may be computationally intensive when a large number of analyses are required, this paper presents an improved version of the 2D model of drive-in racks introduced by Godley. In the improved 2D model, all possible loading scenarios and the influence of pallets on the structural behaviour of the rack are considered. When compared to advanced 3D finite element analyses, the model is able to accurately reproduce the Bending Moment Distribution in the upright, with and without the presence of pallets.

Reinhard Blickhan - One of the best experts on this subject based on the ideXlab platform.

  • Bending Moment Distribution along Swimming Fish
    Journal of Theoretical Biology, 1994
    Co-Authors: Jian-yu Cheng, Reinhard Blickhan
    Abstract:

    Abstract A dynamic analysts of body undulation was carried out for the saithe and an assumed eel-like swimmer. It was found that the three-dimensional unsteady waving plate theory results in a better Momentum balance than the slender body theory. For subcarangiform swimmers the recoil effect requires that the envelope of the waving motion increases non-linearly close to an exponential function starting from a non-zero value at the head. The local Bending Moments necessary to produce such a movement pattern appear almost simultaneously (standing wave) within the middle segment. Within the following caudal segment the Bending Moment travels backward with a phase-velocity close to that of the undulatory wave. For both the eel and the saithe Bending Moments display a rostrally running wave within the rostral body segment. The phase coupling between Moment and Bending Moments roughly agrees with the one observed between movement and muscle activity. Owing to the influence of hydrodynamic forces a phase shift between muscle activity and movement is necessary for both subcarangiform and anguilliform swimmers.

Mayako Yamaguchi - One of the best experts on this subject based on the ideXlab platform.

  • piezoelectric dynamic strain monitoring for detecting local seismic damage in steel buildings
    Smart Materials and Structures, 2013
    Co-Authors: Masahiro Kurata, Xiaohua Li, Kohei Fujita, Mayako Yamaguchi
    Abstract:

    This research presents a methodology for damage detection along with a sensing system for monitoring seismic damage in steel buildings. The system extracts the location and extent of local damage, such as fracture at a beam‐column connection, from changes in the Bending Moment Distribution in a steel Moment-resisting frame. We developed a dynamic strain-based sensing system utilizing piezoelectric film sensors and wireless sensing techniques to estimate the Bending Moments resisted by individual structural members under small amplitude loadings such as ambient vibrations and minor earthquakes. We introduce a new damage index that extracts local damage information from the comparative study of the dynamic strain responses of the structural members before and after a large earthquake event. The damage detection scheme was examined both analytically and numerically using a simple frame example. Then, the entire local damage detection scheme was verified through a series of vibration tests using a one-quarter-scale steel testbed that simulated seismic damage at member ends. (Some figures may appear in colour only in the online journal)

Benoit P. Gilbert - One of the best experts on this subject based on the ideXlab platform.

  • Influence of pallets on the behaviour and design of steel drive-in racks
    Journal of Constructional Steel Research, 2014
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    This paper analyses the influence of horizontal bracing restraints provided by the friction between pallet bases and rail beams on the static behaviour and design of steel drive-in storage racks. The pallet bracing restraints are shown to significantly influence the structural behaviour of the rack, and their effect on the Bending Moment Distribution of the uprights is studied in the paper. The 2D single upright model proposed by Godley is improved in this study by including the restraints provided by the plan flexural stiffness of the rail beams and the friction between the pallets and rail beams. The improved 2D model was found to accurately reproduce the Bending Moment Distributions obtained using 3D advanced finite element analysis. The 2D single upright model is used to analyse 36 drive-in racks under various load case combinations. The paper evaluates the influence of the pallet bracing restraints on the ultimate capacity of drive-in racks, clarifies the loading pattern(s) governing the structural design and determines the friction coefficient, or strength of a restraining device, required to prevent the pallets from sliding. It is shown that while restraints from pallets could potentially be considered in design, they would not lead to more economic structural solutions.

  • Determination of the influence of the pallets on the design of drive-in steel storage racks
    2013
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    This research report analyses the influence of horizontal bracing restraints provided by the friction between pallet bases and rail beams on the static behaviour and design of steel drive-in storage racks. The pallet bracing restraints are shown to significantly influence the structural behaviour of the rack, and their effect on the Bending Moment Distribution of the uprights is studied in the research report. The 2D single upright model proposed by Godley is improved in this study by including the restraints provided by the plan flexural stiffness of the rail beams and the friction between the pallets and rail beams. The improved 2D model was found to accurately reproduce the Bending Moment Distributions obtained using 3D advanced finite element analysis. The 2D single upright model is used to analyse 36 drive-in racks under various load case combinations. The research report evaluates the influence of the pallet bracing restraints on the ultimate capacity of drive-in racks, clarifies the loading pattern(s) governing the structural design and determines the friction coefficient, or strength of a restraining device, required to prevent the pallets from sliding. It is shown that while restraints from pallets could potentially be considered in design, they would not lead to more economic structural solutions.

  • The influence of pallets on the behaviour and design of drive-in steel storage racks - Part I: Behaviour
    2013
    Co-Authors: Benoit P. Gilbert, Lip H. Teh, Romain Badet, Kim J.r. Rasmussen
    Abstract:

    Drive-in steel storage racks represent a popular alternative to the more common selective racks when available space is restricted or when storing the same good. In drive-in racks, the forklift truck drives into the rack and stores the pallets on beam rails on the "first-in last-out" principle. Recent experimental studies have shown that by acting as horizontal ties between uprights, pallets significantly influence the structural behaviour of the rack. However, due to the uncertainty in the degree of friction between the rail beams and the pallets, current industry design practice does not consider this effect. This paper quantifies the influence of the pallets on the Bending Moment Distribution in the uprights using a 3D finite element model calibrated against experimental results on a full scale drive-in rack. Additionally, as 3D models may be computationally intensive when a large number of analyses are required, this paper presents an improved version of the 2D model of drive-in racks introduced by Godley. In the improved 2D model, all possible loading scenarios and the influence of pallets on the structural behaviour of the rack are considered. When compared to advanced 3D finite element analyses, the model is able to accurately reproduce the Bending Moment Distribution in the upright, with and without the presence of pallets.

Fung-kew Kong - One of the best experts on this subject based on the ideXlab platform.

  • high strength concrete continuous deep beams with web reinforcement and shear span variations
    Advances in Structural Engineering, 2004
    Co-Authors: Mohamed Chemrouk, Fung-kew Kong
    Abstract:

    Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-span continuous deep beams. The beams were tested for two shearspan/depth ratios of 0.45 and 0.24 giving clear shear-span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam Bending Moment Distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual Bending Moment Distribution is completely different from that recom...

  • - With web reinforcement and shear-span variations
    2004
    Co-Authors: Mohamed Chemrouk, Fung-kew Kong
    Abstract:

    Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-span continuous deep beams. The beams were tested for two shear- span/depth ratios of 0.45 and 0.24 giving clear shear-span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam Bending Moment Distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual Bending Moment Distribution is completely different from that recommended by these documents, with Moments at spans higher and those at internal supports lower. The tests also showed that the CIRIA guide may be too tolerant and hence unsafe towards bearing failure which, in the presence of an effective pattern of web reinforcement, is the dominant type of failure of reinforced concrete continuous deep beams.

  • High Strength Concrete Continuous Deep Beams — With Web Reinforcement and Shear-Span Variations:
    Advances in Structural Engineering, 2004
    Co-Authors: Mohamed Chemrouk, Fung-kew Kong
    Abstract:

    Tests under two-point loads were carried out to destruction on 12 reinforced concrete two-span continuous deep beams. The beams were tested for two shearspan/depth ratios of 0.45 and 0.24 giving clear shear-span/depth ratio of 0.21 and 0.00 respectively. Various arrangements of web reinforcement were used such as minimum and maximum vertical bars, minimum and maximum horizontal bars and minimum and maximum inclined bars. Sagging and hogging tensile steel was used in accordance with the shallow beam Bending Moment Distribution and was kept constant for all the beams. The results of the present tests are compared with those of the moderately deep beams reported in the litterature by Rogowsky et al. and with the two-beam tests of Leonhardth and Walther. The present tests show that the current codes and design manuals covering continuous deep beams could lead to severe cracking and may be unsafe for this type of structural members. The actual Bending Moment Distribution is completely different from that recom...