The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Song-nan Luo - One of the best experts on this subject based on the ideXlab platform.

  • Wave propagation and transient response of a functionally graded material plate under a Point Impact load in thermal environments
    Applied Mathematical Modelling, 2012
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract In this paper, the wave propagation and transient response of an infinite functionally graded plate under a Point Impact load in thermal environments are studied. The thermal effects and temperature-dependent material properties are taken into account. The temperature field considered is assumed to be a uniform distribution over the plate surface and varies in the thickness direction only. Material properties are assumed to be temperature-dependent, and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. Considering the effects of transverse shear deformation and rotary inertia, the governing equations of the wave propagation in the functionally graded plate are derived from Hamilton’s principle. The analytic dispersion relation of the functionally graded plate is obtained by means of integral transforms and a complete discussion of dispersion for the functionally graded plate is given. Using the dispersion relation and integral transforms, exact integral solutions of the functionally graded plate under a Point Impact load in thermal environments are obtained. The influences of the volume fraction distributions and temperature field on the wave propagation and transient response of functionally graded plates are discussed in detail. The results carried out can be used in the ultrasonic inspection techniques and provide a theoretical basis for engineering applications.

  • Wave propagation and transient response of functionally graded material circular plates under a Point Impact load
    Composites Part B: Engineering, 2011
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract Wave propagation and transient response of an infinite functionally graded circular plate under a Point Impact load are studied. The effective material properties are assumed to vary as a power form of the thickness coordinate. Considering the effects of transverse shear deformation and rotary inertia, the governing equations and analytic dispersion relation of the plate are obtained. Using the dispersion relation and integral transforms, exact integral solutions of the functionally graded plate under a Point Impact load are obtained. The influence of volume fraction distributions on wave propagation and transient response of functionally graded plates is discussed in detail.

  • Wave propagation and transient response of a FGM plate under a Point Impact load based on higher-order shear deformation theory
    Composite Structures, 2011
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract In this paper, the wave propagation and transient response of an infinite functionally graded plate under a Point Impact load are presented. The effective material properties of functionally graded materials (FGMs) for the plate are assumed to vary continuously through the plate thickness and be distributed according to a volume fraction power law along the plate thickness. Based on the higher-order shear deformation theory and considering the effect of the rotary inertia, the governing equations of the wave propagation in the functionally graded plate are derived by using the Hamilton’s principle. The analytic dispersion relation of the functionally graded plate is obtained by means of integral transforms and a complete discussion of dispersion for the functionally graded plate is given. Then, using the dispersion relation and integral transforms, exact integral solutions for the functionally graded plate under a Point Impact load are obtained. The transient response curves of the functionally graded plates are plotted and the influence of volume fraction distributions on transient response of functionally graded plates is analyzed. Finally, the solutions of the higher-order shear deformation theory and the first-order shear deformation theory are studied.

Dan Sun - One of the best experts on this subject based on the ideXlab platform.

  • Wave propagation and transient response of a functionally graded material plate under a Point Impact load in thermal environments
    Applied Mathematical Modelling, 2012
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract In this paper, the wave propagation and transient response of an infinite functionally graded plate under a Point Impact load in thermal environments are studied. The thermal effects and temperature-dependent material properties are taken into account. The temperature field considered is assumed to be a uniform distribution over the plate surface and varies in the thickness direction only. Material properties are assumed to be temperature-dependent, and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. Considering the effects of transverse shear deformation and rotary inertia, the governing equations of the wave propagation in the functionally graded plate are derived from Hamilton’s principle. The analytic dispersion relation of the functionally graded plate is obtained by means of integral transforms and a complete discussion of dispersion for the functionally graded plate is given. Using the dispersion relation and integral transforms, exact integral solutions of the functionally graded plate under a Point Impact load in thermal environments are obtained. The influences of the volume fraction distributions and temperature field on the wave propagation and transient response of functionally graded plates are discussed in detail. The results carried out can be used in the ultrasonic inspection techniques and provide a theoretical basis for engineering applications.

  • Wave propagation and transient response of functionally graded material circular plates under a Point Impact load
    Composites Part B: Engineering, 2011
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract Wave propagation and transient response of an infinite functionally graded circular plate under a Point Impact load are studied. The effective material properties are assumed to vary as a power form of the thickness coordinate. Considering the effects of transverse shear deformation and rotary inertia, the governing equations and analytic dispersion relation of the plate are obtained. Using the dispersion relation and integral transforms, exact integral solutions of the functionally graded plate under a Point Impact load are obtained. The influence of volume fraction distributions on wave propagation and transient response of functionally graded plates is discussed in detail.

  • Wave propagation and transient response of a FGM plate under a Point Impact load based on higher-order shear deformation theory
    Composite Structures, 2011
    Co-Authors: Dan Sun, Song-nan Luo
    Abstract:

    Abstract In this paper, the wave propagation and transient response of an infinite functionally graded plate under a Point Impact load are presented. The effective material properties of functionally graded materials (FGMs) for the plate are assumed to vary continuously through the plate thickness and be distributed according to a volume fraction power law along the plate thickness. Based on the higher-order shear deformation theory and considering the effect of the rotary inertia, the governing equations of the wave propagation in the functionally graded plate are derived by using the Hamilton’s principle. The analytic dispersion relation of the functionally graded plate is obtained by means of integral transforms and a complete discussion of dispersion for the functionally graded plate is given. Then, using the dispersion relation and integral transforms, exact integral solutions for the functionally graded plate under a Point Impact load are obtained. The transient response curves of the functionally graded plates are plotted and the influence of volume fraction distributions on transient response of functionally graded plates is analyzed. Finally, the solutions of the higher-order shear deformation theory and the first-order shear deformation theory are studied.

Alan Bowling - One of the best experts on this subject based on the ideXlab platform.

  • Modeling three-dimensional surface-to-surface rigid contact and Impact
    Multibody System Dynamics, 2019
    Co-Authors: Abhishek Chatterjee, Alan Bowling
    Abstract:

    This work presents a rigid body framework for analyzing three-dimensional surface contacts and Impacts as a simultaneous multi-Point Impact problem with friction. A method is developed to address the indeterminacy issue typically associated with multi-Point contact and Impact analysis. This is accomplished using the constraints on impulses and contact forces defined by the Coulomb friction law and rigid body constraints. The proposed approach relies on a global interpretation of Stronge’s energetic coefficient of restitution (ECOR) to maintain energetic consistency. A key aspect of this work involves addressing the three-dimensionality of this problem, which requires a numerical integration in the impulse domain to address the slip/no-slip behavior in the tangential plane of the Impact. This work also models the transition to contact after a series of Impacts, and proposes a method for enforcing frictional contact constraints. Several examples of simulation results using the proposed method are presented here.

  • Resolving the Unique Invariant Slip-Direction in Rigid Three-Dimensional Multi-Point Impacts at Stick-Slip Transitions
    Volume 6: 14th International Conference on Multibody Systems Nonlinear Dynamics and Control, 2018
    Co-Authors: Abhishek Chatterjee, Alan Bowling
    Abstract:

    This work presents a new approach for resolving the unique invariant slip direction at Stick-Slip Transition during Impact. The solution method presented in this work is applicable to both single-Point and multi-Point Impact problems. The proposed method utilizes rigid body constraints to resolve the Impact forces at all collision Points in terms of a single independent Impact forces parameter. This work also uses an energetic coefficient of restitution to terminate Impact events, thereby yielding energetically consistent post-Impact behavior.Copyright © 2018 by ASME

  • Analytic solution for planar indeterminate Impact problems using an energy constraint
    Multibody System Dynamics, 2018
    Co-Authors: Abhishek Chatterjee, Adrian Rodriguez, Alan Bowling
    Abstract:

    This work proposes an analytic method for resolving planar multi-Point indeterminate Impact problems for rigid-body systems. An event-based approach is used to detect Impact events, and constraints consistent with the rigid-body assumption are used to resolve the indeterminacy associated with multi-Point Impact analysis. The work-energy relation is utilized to determine post-Impact velocities based on an energetic coefficient of restitution to model energy dissipation, thereby yielding an energetically consistent set of post-Impact velocities based on Stronge’s energetic coefficient of restitution for the treatment of rigid Impacts. The effect of stick–slip transition is analyzed based on Coulomb friction. This paper also discusses the transition from Impact to contact. This analysis is essential for considering the rocking block problem that is used as an example herein. The predictions of the model for the rocking block problem are compared to experimental results published in the literature. An example of a planar ball undergoing two-Point Impact is also presented.

  • Analytic Solution for Planar Indeterminate Multiple Point Impact Problems With Coulomb Friction
    Volume 6: 10th International Conference on Multibody Systems Nonlinear Dynamics and Control, 2014
    Co-Authors: Adrian Rodriguez, Alan Bowling
    Abstract:

    This work analyzes the effects of the stick-slip transition of planar rigid body systems undergoing simultaneous, multiple Point Impact with Coulomb friction. A discrete, algebraic approach is used in conjunction with an event-driven scheme which detects Impact events. The system equations of motion for the examples considered are indeterminate with respect to the Impact forces. Constraints consistent with rigid body assumptions are implemented to overcome the indeterminacy. The post-Impact velocities of a system are determined by exploiting the work-energy relationship of a collision and using an energetic coefficient of restitution to model energy dissipation. These developments lead to a unique and energetically consistent solution to the post-Impact velocities. A frictionless rocking block example is analyzed as a benchmark case and compared to experimental results to demonstrate the accuracy of the proposed method. Simulation results are also presented for a planar ball example with friction.Copyright © 2014 by ASME

  • Analytic Solution to 3-Dimensional, Single Point Collision Problems Using Stronge's Hypothesis
    2012
    Co-Authors: Adrian Rodriguez, Alan Bowling
    Abstract:

    This work presents a unique algorithm to obtain an analytic solution to the post-Impact behavior of threedimensional (3D) rigid body collision problems. The proposed method is developed to address the issues which arise in the sticking region for single Point Impact with friction. Stronge’s hypothesis, which incorporates the principles of the work-energy theorem is used to treat the energy lost during the rigid body collision. A discrete, algebraic modeling approach is used with an event-driven function which finds Impact events. Coulomb friction is used to describe the relationsh ip between the normal and tangential impulses. A benchmark example is considered to evaluate the effectiveness of the proposed algorithm.

Sailendra Meduri - One of the best experts on this subject based on the ideXlab platform.

  • polymer matrix composites subjected to low velocity Impact effect of laminate configuration
    Composites Science and Technology, 2001
    Co-Authors: N K Naik, Sailendra Meduri
    Abstract:

    Abstract Effect of laminate configuration on the Impact behaviour of different polymer-matrix composites subjected to a transverse central low-velocity Point Impact load has been studied. For this a 3D transient finite-element analysis code using a modified Hertz law has been used. Quadratic failure criteria have been used to predict in-plane and interlaminar failure initiation. The studies have been carried out with plate dimensions of 150 mm×150 mm×6 mm with a simply supported boundary condition. For these studies, an incident Impact velocity of 3 m/s and an Impactor mass of 50 g have been used. Studies have been carried out on different mixed composites, cross-ply laminates, woven-fabric composites and 3D composites. It is observed that mixing of unidirectional and woven-fabric layers leads to the reduction of the failure function.

  • Polymer Matrix Woven Fabric Composites Subjected to Low Velocity Impact: Part III—Effect of Incident Impact Velocity and Impactor Mass
    Journal of Reinforced Plastics and Composites, 2001
    Co-Authors: N K Naik, Sailendra Meduri, Y. Chandrasekher
    Abstract:

    The studies have been carried out on the damage initiation behavior of polymer matrix woven fabric composite plates subjected to a transverse central low velocity Point Impact load. Specifically, the effect of incident Impact velocity and Impactor mass for the same incident Impact energy on the Impact behavior has been investigated with a square plate of 150 mm × 150 mm x 6 mm. The material systems considered are: E-glass/epoxy and T300/5208 carbon/epoxy woven fabric composites. Inplane failure of the layers in the form of matrix cracking / lamina splitting and delaminations were the primary objectives of the study. The studies have been carried out using an inhouse Finite Element Analysis code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. It is observed that the use of incident Impact energy alone as a parameter to characterize the Impact behavior is inadequate. Instead, the effect of both incident Impact velocity and Impactor mass should be considered separately.

  • polymer matrix woven fabric composites subjected to low velocity Impact part ii effect of plate thickness
    Journal of Reinforced Plastics and Composites, 2000
    Co-Authors: N K Naik, Sailendra Meduri, Chandra Y Sekhe
    Abstract:

    The studies have been carried out on the damage initiation behavior of polymer matrix woven fabric (WF) composite plates subjected to a transverse central low velocity Point Impact load. Specifically, the effect of composite plate thickness on the Impact behavior has been investigated with a square plate of 150 mm x 150 mm with thicknesses varying from 4.5 mm to 8.0 mm. The material systems considered are: E-glass/epoxy and T300/5208 carbon/epoxy. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The studies have been carried out using an inhouse Finite Element Analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. General observations on the Impact behavior of polymer matrix WF composites as a function of plate thickness have been presented.

  • polymer matrix woven fabric composites subjected to low velocity Impact part i damage initiation studies
    Journal of Reinforced Plastics and Composites, 2000
    Co-Authors: N K Naik, Chandra Y Sekhe, Sailendra Meduri
    Abstract:

    An investigation was undertaken to study the damage initiation behavior in polymer matrix laminated composite plates subjected to a transverse central low velocity Point Impact load. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The study has been carried out using modified Hertz contact law and an inhouse three-dimensional transient finite element analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. The inhouse FEA code was validated with other analytical studies and the experimental results in our earlier work. The present studies have been carried out on different plain weave fabric laminated composite plates, simply supported on all four sides. For comparison, Impact behavior of balanced symmetric crossply (CP) laminates made of unidirectional (UD) layers and UD composites has been included. The studies have been carried ...

  • damage in woven fabric composites subjected to low velocity Impact
    Composites Science and Technology, 2000
    Co-Authors: N K Naik, Chandra Y Sekhe, Sailendra Meduri
    Abstract:

    Abstract The behaviour of woven-fabric laminated composite plates has been studied under transverse central low-velocity Point Impact by using a modified Hertz law and a 3D transient finite-element analysis code. The in-plane failure behaviour of the composites has been evaluated by means of a failure function based on the Tsai-Hill quadratic failure criterion. The effect of fabric geometry on the Impact behaviour of woven-fabric composites has been studied. For comparison, the Impact behaviour of balanced, symmetric, crossply laminates made of unidirectional layers and unidirectional composites has been included. The studies have been carried out with plate dimensions of 150 mm×150 mm×6 mm for a supported boundary condition. For these studies, incident Impact velocities of 3 and 1 m/s and an Impactor mass of 50 gm have been used. It is observed that the in-plane failure function is lower for woven-fabric laminates than for crossply laminates, indicating that woven-fabric laminates are more resistant to Impact damage.

N K Naik - One of the best experts on this subject based on the ideXlab platform.

  • polymer matrix composites subjected to low velocity Impact effect of laminate configuration
    Composites Science and Technology, 2001
    Co-Authors: N K Naik, Sailendra Meduri
    Abstract:

    Abstract Effect of laminate configuration on the Impact behaviour of different polymer-matrix composites subjected to a transverse central low-velocity Point Impact load has been studied. For this a 3D transient finite-element analysis code using a modified Hertz law has been used. Quadratic failure criteria have been used to predict in-plane and interlaminar failure initiation. The studies have been carried out with plate dimensions of 150 mm×150 mm×6 mm with a simply supported boundary condition. For these studies, an incident Impact velocity of 3 m/s and an Impactor mass of 50 g have been used. Studies have been carried out on different mixed composites, cross-ply laminates, woven-fabric composites and 3D composites. It is observed that mixing of unidirectional and woven-fabric layers leads to the reduction of the failure function.

  • Polymer Matrix Woven Fabric Composites Subjected to Low Velocity Impact: Part III—Effect of Incident Impact Velocity and Impactor Mass
    Journal of Reinforced Plastics and Composites, 2001
    Co-Authors: N K Naik, Sailendra Meduri, Y. Chandrasekher
    Abstract:

    The studies have been carried out on the damage initiation behavior of polymer matrix woven fabric composite plates subjected to a transverse central low velocity Point Impact load. Specifically, the effect of incident Impact velocity and Impactor mass for the same incident Impact energy on the Impact behavior has been investigated with a square plate of 150 mm × 150 mm x 6 mm. The material systems considered are: E-glass/epoxy and T300/5208 carbon/epoxy woven fabric composites. Inplane failure of the layers in the form of matrix cracking / lamina splitting and delaminations were the primary objectives of the study. The studies have been carried out using an inhouse Finite Element Analysis code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. It is observed that the use of incident Impact energy alone as a parameter to characterize the Impact behavior is inadequate. Instead, the effect of both incident Impact velocity and Impactor mass should be considered separately.

  • polymer matrix woven fabric composites subjected to low velocity Impact part ii effect of plate thickness
    Journal of Reinforced Plastics and Composites, 2000
    Co-Authors: N K Naik, Sailendra Meduri, Chandra Y Sekhe
    Abstract:

    The studies have been carried out on the damage initiation behavior of polymer matrix woven fabric (WF) composite plates subjected to a transverse central low velocity Point Impact load. Specifically, the effect of composite plate thickness on the Impact behavior has been investigated with a square plate of 150 mm x 150 mm with thicknesses varying from 4.5 mm to 8.0 mm. The material systems considered are: E-glass/epoxy and T300/5208 carbon/epoxy. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The studies have been carried out using an inhouse Finite Element Analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. General observations on the Impact behavior of polymer matrix WF composites as a function of plate thickness have been presented.

  • polymer matrix woven fabric composites subjected to low velocity Impact part i damage initiation studies
    Journal of Reinforced Plastics and Composites, 2000
    Co-Authors: N K Naik, Chandra Y Sekhe, Sailendra Meduri
    Abstract:

    An investigation was undertaken to study the damage initiation behavior in polymer matrix laminated composite plates subjected to a transverse central low velocity Point Impact load. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The study has been carried out using modified Hertz contact law and an inhouse three-dimensional transient finite element analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. The inhouse FEA code was validated with other analytical studies and the experimental results in our earlier work. The present studies have been carried out on different plain weave fabric laminated composite plates, simply supported on all four sides. For comparison, Impact behavior of balanced symmetric crossply (CP) laminates made of unidirectional (UD) layers and UD composites has been included. The studies have been carried ...

  • damage in woven fabric composites subjected to low velocity Impact
    Composites Science and Technology, 2000
    Co-Authors: N K Naik, Chandra Y Sekhe, Sailendra Meduri
    Abstract:

    Abstract The behaviour of woven-fabric laminated composite plates has been studied under transverse central low-velocity Point Impact by using a modified Hertz law and a 3D transient finite-element analysis code. The in-plane failure behaviour of the composites has been evaluated by means of a failure function based on the Tsai-Hill quadratic failure criterion. The effect of fabric geometry on the Impact behaviour of woven-fabric composites has been studied. For comparison, the Impact behaviour of balanced, symmetric, crossply laminates made of unidirectional layers and unidirectional composites has been included. The studies have been carried out with plate dimensions of 150 mm×150 mm×6 mm for a supported boundary condition. For these studies, incident Impact velocities of 3 and 1 m/s and an Impactor mass of 50 gm have been used. It is observed that the in-plane failure function is lower for woven-fabric laminates than for crossply laminates, indicating that woven-fabric laminates are more resistant to Impact damage.