The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
L A Louca - One of the best experts on this subject based on the ideXlab platform.
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dynamic performance of simply supported Rigid Plastic square plates subject to localized blast loading
Journal of Engineering Mechanics-asce, 2019Co-Authors: N Mehregania, A S Fallah, L A LoucaAbstract:AbstractThis paper presents the theoretical solution to the response of a square plate undergoing Plastic deformation due to a generic localized blast pulse. A localized blast load function was ass...
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dynamic performance of simply supported Rigid Plastic circular thick steel plates subjected to localized blast loading
Journal of Engineering Mechanics-asce, 2014Co-Authors: K Micallef, A S Fallah, D J Pope, L A LoucaAbstract:AbstractClose-in explosive charges, such as improvised explosive devices, produce localized blast loadings that can potentially cause damage to property in military and civil structures and/or loss of life. Because the localized short-duration blast pulse affects most severely a small area of a plated structure, the plate’s boundary effects are not as influential as they would be when quasi-static or even a global blast loading is applied, and thus full plate action may not be used. Many common structural forms are composed of individual plated elements, and thus the investigation of localized blast loading effects on plates is an important aspect that leads to understanding the integral behavior. Typically, plates are made of ductile metallic materials, such as steel, which exhibit considerable postyield deformation capacity when subjected to such extreme dynamic loads. An analytical study of the dynamic Plastic response of Rigid Plastic plated structures is the aim of the current study. A circular plate...
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the dynamic performance of simply supported Rigid Plastic circular steel plates subjected to localised blast loading
International Journal of Mechanical Sciences, 2012Co-Authors: K Micallef, A S Fallah, D J Pope, L A LoucaAbstract:Abstract Near-field explosive charges, such as buried land mines, produce localised blast loadings which can potentially cause damage to property and/or loss of life in both military and civil structures. As the localised short duration blast pulse affects most severely a small area of a plated structure, boundary effects are not as significant as they are when a quasi-static or global blast loading is applied and full plate action may not be utilised. Many common structural forms are composed of individual plated elements and thus the investigation of localised blast loading effects on plates is a prerequisite to understanding the integral behaviour. Typically, plates are made of ductile materials such as steel, which exhibit considerable post-yield deformation capacity when subjected to such extreme dynamic loads. Analytical study of the dynamic Plastic response of Rigid-Plastic plated structures is the aim of the present study. A circular plate is studied in the present work and a general form of a localised blast loading function with a spatial variation having a central radial zone with constant pressure and exponentially decaying profile outside the zone is assumed. Assuming that steel exhibits perfectly Plastic behaviour and ignoring membrane action, transverse shear and rotatory inertia effects, the static Plastic collapse pressure is initially found and the analysis is extended to take into account the inertial effects arising from dynamic loading. Results for the permanent transverse displacements are found for rectangular and linearly and exponentially decaying pulse loads. For high loads and/or loads of short duration, it was found that the permanent transverse displacement can be found by replacing the applied pulse load by means of an impulsive velocity without great loss of accuracy. Good correlation with numerical simulations obtained from ABAQUS/Explicit is achieved (within 15% accuracy) for plate geometries falling within the identified limits where membrane and shear effects are negligible. The predicted final transverse displacements are found to be dependent on the loading pulse shape, but the pulse-shape effects are eliminated by using the correlation parameters (effective impulse and pressure) advocated by Youngdahl (1971) [52] to give a single pulse shape-independent curve for the final plate deflection as a function of the effective pressure and effective impulse.
V A Lubarda - One of the best experts on this subject based on the ideXlab platform.
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on the analysis of pure bending of Rigid Plastic beams in strain gradient Plasticity
European Journal of Mechanics A-solids, 2017Co-Authors: V A LubardaAbstract:Abstract The complete stress field, including the microstress, the moment-stress, and the line forces are derived for the pure bending of a Rigid-Plastic beam of rectangular cross-section in the model of strain-gradient Plasticity. The workless spherical parts of the microstress and the moment-stress tensors are incorporated in the analysis. Their determination is shown to be of importance for the fulfilment of the higher-order traction boundary conditions, the physical interpretation of line forces, and their contributions to bending moments. Three equivalent methods are used to derive the moment-curvature relationship for any of the gradient-enhanced effective Plastic strain measures from the considered broad class of these measures. Specific results are given for the selected choice of the stress-strain relationship describing the uniaxial tension test. Closed-form analytical expressions are obtained in the case of linear hardening, and in some cases of nonlinear hardening. The analysis of the plane-strain bending of thin foils is also presented. In this case there are two sets of line forces along the edges of the beam. The relationships between the applied bending moment and the curvature, and between the lateral bending moment and the curvature are derived and discussed. The lateral bending moment along the lateral sides of the beam, needed to keep the plane-strain mode of deformation, is one-half of the applied bending moment.
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Rigid Plastic torsion of a hollow tube in strain gradient Plasticity
International Journal of Solids and Structures, 2016Co-Authors: V A LubardaAbstract:Abstract Closed-form expressions for the Cauchy stress, microstress, moment-stress, and the torque-twist relationship in a twisted hollow circular tube are derived for a Rigid-Plastic strain-gradient Plasticity. This is accomplished for any of the gradient-enhanced effective Plastic strain measures from a considered broad class of these measures. Numerical results are given and discussed for the two most frequently utilized measures and for the three adopted stress-strain relationships modeling the uniaxial tension test. Solid circular rods and thin-walled tubes are both considered. The existence of the line forces is also discussed from the standpoint of the basic equilibrium considerations and the principle of virtual work.
K Micallef - One of the best experts on this subject based on the ideXlab platform.
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dynamic performance of simply supported Rigid Plastic circular thick steel plates subjected to localized blast loading
Journal of Engineering Mechanics-asce, 2014Co-Authors: K Micallef, A S Fallah, D J Pope, L A LoucaAbstract:AbstractClose-in explosive charges, such as improvised explosive devices, produce localized blast loadings that can potentially cause damage to property in military and civil structures and/or loss of life. Because the localized short-duration blast pulse affects most severely a small area of a plated structure, the plate’s boundary effects are not as influential as they would be when quasi-static or even a global blast loading is applied, and thus full plate action may not be used. Many common structural forms are composed of individual plated elements, and thus the investigation of localized blast loading effects on plates is an important aspect that leads to understanding the integral behavior. Typically, plates are made of ductile metallic materials, such as steel, which exhibit considerable postyield deformation capacity when subjected to such extreme dynamic loads. An analytical study of the dynamic Plastic response of Rigid Plastic plated structures is the aim of the current study. A circular plate...
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the dynamic performance of simply supported Rigid Plastic circular steel plates subjected to localised blast loading
International Journal of Mechanical Sciences, 2012Co-Authors: K Micallef, A S Fallah, D J Pope, L A LoucaAbstract:Abstract Near-field explosive charges, such as buried land mines, produce localised blast loadings which can potentially cause damage to property and/or loss of life in both military and civil structures. As the localised short duration blast pulse affects most severely a small area of a plated structure, boundary effects are not as significant as they are when a quasi-static or global blast loading is applied and full plate action may not be utilised. Many common structural forms are composed of individual plated elements and thus the investigation of localised blast loading effects on plates is a prerequisite to understanding the integral behaviour. Typically, plates are made of ductile materials such as steel, which exhibit considerable post-yield deformation capacity when subjected to such extreme dynamic loads. Analytical study of the dynamic Plastic response of Rigid-Plastic plated structures is the aim of the present study. A circular plate is studied in the present work and a general form of a localised blast loading function with a spatial variation having a central radial zone with constant pressure and exponentially decaying profile outside the zone is assumed. Assuming that steel exhibits perfectly Plastic behaviour and ignoring membrane action, transverse shear and rotatory inertia effects, the static Plastic collapse pressure is initially found and the analysis is extended to take into account the inertial effects arising from dynamic loading. Results for the permanent transverse displacements are found for rectangular and linearly and exponentially decaying pulse loads. For high loads and/or loads of short duration, it was found that the permanent transverse displacement can be found by replacing the applied pulse load by means of an impulsive velocity without great loss of accuracy. Good correlation with numerical simulations obtained from ABAQUS/Explicit is achieved (within 15% accuracy) for plate geometries falling within the identified limits where membrane and shear effects are negligible. The predicted final transverse displacements are found to be dependent on the loading pulse shape, but the pulse-shape effects are eliminated by using the correlation parameters (effective impulse and pressure) advocated by Youngdahl (1971) [52] to give a single pulse shape-independent curve for the final plate deflection as a function of the effective pressure and effective impulse.
J K Spelt - One of the best experts on this subject based on the ideXlab platform.
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impact of Rigid angular particles with fully Plastic targets part i analysis
International Journal of Mechanical Sciences, 2000Co-Authors: M Papini, J K SpeltAbstract:Abstract The erosion of substrates of arbitrary dynamic hardness and friction coefficient, due to the impact of individual angular particles, was analyzed with the purpose of predicting crater size, shape, and rebound parameters as a function of incident particle velocity, angle, orientation, and shape. A Rigid-Plastic theory due to Hutchings (International Journal of Mechanical Sciences 1997; 19:45–52), developed for square plates impacting frictionless surfaces, is generalized for arbitrarily shaped particles impacting surfaces having nonzero friction. The specific case of symmetric angular particles of arbitrary angularity is studied in detail. The model is shown to match Hutchings’ [1] experimental data for square steel plates on smooth steel surfaces. In a companion paper (Papini, Spelt, under review), a parametric study of the input parameters is presented.
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impact of Rigid angular particles with fully Plastic targets part ii parametric study of erosion phenomena
International Journal of Mechanical Sciences, 2000Co-Authors: M Papini, J K SpeltAbstract:Abstract In the accompanying paper (Papini M, Spelt JK. Impact of Rigid angular particles with fully-Plastic targets. Part I: Analysis. International Journal of Mechanical Sciences 2000;42(5):991–1006), the erosion of targets of arbitrary dynamic hardness and friction coefficient due to the impact of individual angular particles was analyzed with the purpose of predicting crater size, shape, and rebound parameters as a function of incident velocity, angle, particle orientation, and shape. A Rigid-Plastic model of impact was utilized, and the specific case of symmetric angular particles was studied in detail. In this paper, the model is used to predict crater size in a parametric study of the effect of particle size, shape, incident velocity and orientation, as well as target dynamic hardness and friction coefficient. A dimensional analysis revealed some useful relevant dimensionless parameters. The conditions which maximize the crater size are identified for both constant friction and frictionless surfaces. A parametric study is presented to identify the effects of the most important parameters and can be used as a tool to guide further experimentation.
Kalipada Maity - One of the best experts on this subject based on the ideXlab platform.
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a class of slip line field solutions for metal machining with elastic contact
Journal of Materials Processing Technology, 1999Co-Authors: Kalipada MaityAbstract:Abstract The present investigation is concerned with a class of slip-line field solutions for metal machining involving chip curl. The solutions under consideration were first proposed by Kudo, who had found them to be statically inadmissible. In this study, these fields are analysed by assuming an elastic contact zone beyond the Plastically stressed region. Force and moment equilibrium of the chip is realised by assuming the Rigid chip to be acted upon by prescribed normal and shear forces in the elastic zone and by forces in the Rigid–Plastic boundary. Results are presented for variation in contact length, cutting force and thrust force, with variation in rake angle and interface friction conditions, both for power-law and exponential pressure distributions in the elastic contact zone.
