Viscoelastic response of a floating ice plate to a steadily moving load

1988 ◽  
Vol 196 ◽  
pp. 409-430 ◽  
Author(s):  
R. J. Hosking ◽  
A. D. Sneyd ◽  
D. W. Waugh
Keyword(s):  
Asymptotic Theory ◽  
Moving Load ◽  
Memory Function ◽  
Point Load ◽  
Flexural Waves ◽  
Moving Vehicle ◽  
Viscoelastic Theory ◽  
Subcritical Speed ◽  
Moving Line ◽  
Two Parameter

Viscoelastic theory is used to describe the response of a floating ice sheet to a moving vehicle. We adopt a two-parameter memory function to describe the behaviour of the ice, subjected to a steadily moving line or point load. The viscoelastic dissipation produces an asymmetric quasi-static response at subcritical speed, renders a finite response at the critical speed, and damps the shorter leading waves rather more severely than the longer trailing waves at supercritical speed. We extend earlier asymptotic theory to consider the anisotropic damping of the flexural waves. There is enhanced agreement between theory and experiment.

Dynamics of Plate Generated by Moving Harmonic Loads

2005 ◽  
Vol 72 (5) ◽  
pp. 772-777 ◽  
Author(s):  
Lu Sun
Keyword(s):  
Moving Load ◽  
Point Load ◽  
Harmonic Load ◽  
Maximum Displacement ◽  
Moving Vehicle ◽  
Vehicle Load ◽  
Airport Pavement ◽  
Winkler Elastic Foundation ◽  
Approximate Relationship ◽  
Moving Harmonic Load

A thin plate resting on a Winkler elastic foundation subject to a moving harmonic load can be used as the model for highway and airport pavement under moving vehicle load and many other applications. The study of dynamic response of the plate thus becomes very important. In this paper we study the dynamic displacement of a plate caused by a moving harmonic line and point load. The solution is represented by the convolution of dynamic Green’s function of plate. An approximate relationship between critical load velocity and critical frequency is established analytically. It is found that the maximum displacement response occurs at the center of the moving load and travels at the same speed with the load.

scholarly journals The Effects of Moving Load on the Hydroelastic Response of a Very Large Floating Structure

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Le Zhu ◽  
Fei Shao ◽  
Qian Xu ◽  
Yonggang Sun ◽  
Qingna Ma
Keyword(s):  
Moving Load ◽  
Fluid Motion ◽  
Elastic Beam ◽  
Point Load ◽  
Floating Structure ◽  
Very Large Floating Structure ◽  
External Point ◽  
The Fourier Transform ◽  
The Time Domain ◽  
Hydroelastic Response

The hydroelastic response of a very large floating structure in regular waves suffering an external moving point load is considered. The linearized velocity potential theory is adopted to describe the fluid flow. To take into account the coupled effects of the structure deformation and fluid motion, the structure is divided into multiple segments and connected by an elastic beam. Then through adding a stiffness matrix arising from the elastic beam into the multiple bodies coupled motion equations, the hydroelastic response is considered. By applying the Fourier transform to the obtained frequency domain coefficients, the motion equation is transformed into the time domain and the external point load is further considered. The accuracy and effectiveness of the proposed method are verified through the comparison with experimental results. Finally, extensive results are provided, and the effects of the moving point load on the hydroelastic response of the very large floating structure are investigated in detail.

scholarly journals Dynamic Behavior of a Bidirectional Functionally Graded Sandwich Beam under Nonuniform Motion of a Moving Load

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Dinh Kien Nguyen ◽  
An Ninh Thi Vu ◽  
Ngoc Anh Thi Le ◽  
Vu Nam Pham
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Moving Load ◽  
Sandwich Beam ◽  
Point Load ◽  
Functionally Graded ◽  
Beam Model ◽  
Material Distribution ◽  
Aspect Ratios ◽  
Nonuniform Motion

A bidirectional functionally graded Sandwich (BFGSW) beam model made from three distinct materials is proposed and its dynamic behavior due to nonuniform motion of a moving point load is investigated for the first time. The beam consists of three layers, a homogeneous core, and two functionally graded face sheets with material properties varying in both the thickness and longitudinal directions by power gradation laws. Based on the first-order shear deformation beam theory, a finite beam element is derived and employed in computing dynamic response of the beam. The element which used the shear correction factor is simple with the stiffness and mass matrices evaluated analytically. The numerical result reveals that the material distribution plays an important role in the dynamic response of the beam, and the beam can be designed to meet the desired dynamic magnification factor by appropriately choosing the material grading indexes. A parametric study is carried out to highlight the effects of the material distribution, the beam layer thickness and aspect ratios, and the moving load speed on the dynamic characteristics. The influence of acceleration and deceleration of the moving load on the dynamic behavior of the beam is also examined and highlighted.

Closed-Form Representation of Beam Response to Moving Line Loads

2000 ◽  
Vol 68 (2) ◽  
pp. 348-350 ◽  
Author(s):  
Lu Sun
Keyword(s):  
Closed Form ◽  
Moving Load ◽  
Closed Form Solution ◽  
Form Solution ◽  
Winkler Foundation ◽  
Line Load ◽  
State Response ◽  
Form Representation ◽  
Mach Numbers ◽  
Moving Line

Fourier transform is used to solve the problem of steady-state response of a beam on an elastic Winkler foundation subject to a moving constant line load. Theorem of residue is employed to evaluate the convolution in terms of Green’s function. A closed-form solution is presented with respect to distinct Mach numbers. It is found that the response of the beam goes to unbounded as the load travels with the critical velocity. The maximal displacement response appears exactly under the moving load and travels at the same speed with the moving load in the case of Mach numbers being less than unity.

Moving Load on a Fluid-Solid Interface: Subsonic and Intersonic Regimes

1973 ◽  
Vol 40 (4) ◽  
pp. 885-890 ◽  
Author(s):  
T. C. Kennedy ◽  
G. Herrmann
Keyword(s):  
Steady State ◽  
Moving Load ◽  
Point Load ◽  
Numerical Results ◽  
Plane Interface ◽  
Steady State Response ◽  
State Response ◽  
Solid Interface

The steady-state response of a semi-infinite solid, with an overlying semi-infinite fluid, subjected at the plane interface to a moving point load is determined for subsonic and intersonic load velocities. Some numerical results for the displacements at the interface are presented and compared to the results obtained in the absence of the fluid.

Steady-State Wave Propagation in Multilayered Viscoelastic Media Excited by a Moving Dynamic Distributed Load

2009 ◽  
Vol 76 (4) ◽  
Author(s):  
Lu Sun ◽  
Wenjun Gu ◽  
Feiquan Luo
Keyword(s):  
Steady State ◽  
Moving Load ◽  
Impulse Response Function ◽  
Constitutive Models ◽  
Numerical Algorithms ◽  
Point Load ◽  
Fast Evaluation ◽  
Viscoelastic Media ◽  
Distributed Load ◽  
Novel Approach

An analytical solution of steady-state dynamic response of a multilayered viscoelastic medium to a moving distributed load is obtained using a novel approach that combines transfer matrix method with Sun’s convolution representation integrated over impulse response function of the layered medium. The layered media under consideration include elastic and viscoelastic media with four different viscoelastic constitutive models, while the moving load is allowed to have a circular spatial distribution, which is more realistic for mimicking tire footprint than a commonly used point load. Efficient numerical algorithms based on fast evaluation of various integral transformations and their inversions are developed and validated through numerical example.

scholarly journals Moving Load Identification with Long Gauge Fiber Optic Strain Sensing

2021 ◽  
Vol 16 (3) ◽  
pp. 131-158
Author(s):  
Qingqing Zhang ◽  
Wenju Zhao ◽  
Jian Zhang
Keyword(s):  
Fiber Optic ◽  
Moving Load ◽  
Field Testing ◽  
Maximum Strain ◽  
Load Identification ◽  
Moving Vehicle ◽  
Moving Vehicles ◽  
Structural Responses ◽  
Vehicle Loads ◽  
Moving Load Identification

Moving load identification has been researched with regard to the analysis of structural responses, taking into consideration that the structural responses would be affected by the axle parameters, which in its turn would complicate obtaining the values of moving vehicle loads. In this research, a method that identifies the loads of moving vehicles using the modified maximum strain value considering the long-gauge fiber optic strain responses is proposed. The method is based on the assumption that the modified maximum strain value caused only by the axle loads may be easily used to identify the load of moving vehicles by eliminating the influence of these axle parameters from the peak value, which is not limited to a specific type of bridges and can be applied in conditions, where there are multiple moving vehicles on the bridge. Numerical simulations demonstrate that the gross vehicle weights (GVWs) and axle weights are estimated with high accuracy under complex vehicle loads. The effectiveness of the proposed method was verified through field testing of a continuous girder bridge. The identified axle weights and gross vehicle weights are comparable with the static measurements obtained by the static weighing.

scholarly journals Dynamic analysis of prestressed Bernoulli beams resting on two-parameter foundation under moving harmonic load

2006 ◽  
Vol 28 (3) ◽  
pp. 176-188 ◽  
Author(s):  
Nguyen Dinh Kien ◽  
Bui Thanh Hai
Keyword(s):  
Dynamic Analysis ◽  
Moving Load ◽  
Excitation Frequency ◽  
Harmonic Load ◽  
Left Hand ◽  
Moving Harmonic Load ◽  
Load Vector ◽  
Hermitian Polynomials ◽  
Current Loading ◽  
Two Parameter

This paper describes the dynamic analysis of prestressed Bernoulli beams resting on a two-parameter elastic foundation under a moving harmonic load by the finite element method. Using the cubic Hermitian polynomials as interpolation functions for the deflection, the stiffness of the Bernoulli beam element augmented by that of the foundation support and prestress is formulated. The nodal load vector is derived using the polynomials with the abscissa measured from the left-hand node of the current loading element to the position of the moving load. Using the formulated element, the dynamic response of the beams is computed with the aid of the direct integration Newmark method. The effects of the foundation support, prestress as well as excitation frequency, velocity and acceleration on the dynamic characteristics of the beams are investigated in detail and highlighted.

scholarly journals Model-Order-Reduction Approach for Structural Health Monitoring of Large Deployed Structures With Localized Operational Excitations

2021 ◽  
Author(s):  
Mohamed Aziz Bhouri
Keyword(s):  
Correlation Function ◽  
Time Domain ◽  
Numerical Solutions ◽  
Moving Load ◽  
Order Reduction ◽  
Training Dataset ◽  
Support Vector ◽  
Reduced Basis ◽  
Moving Vehicle ◽  
Classification Errors

Abstract We present a simulation-based classification approach for large deployed structures with localized operational excitations. The method extends the two-level Port-Reduced Reduced-Basis Component (PR-RBC) technique to provide faster solution estimation to the hyperbolic partial differential equation of time-domain elastodynamics with a moving load. Time-domain correlation function-based features are built in order to train classifiers such as Artificial Neural Networks and Support-Vector Machines and perform damage detection. The method is tested on a bridge-shaped structure with a moving vehicle (playing the role of a digital twin) in order to detect cracks’ existence. Such problem has 45 parameters and shows the merits of the two-level PR-RBC approach and of the correlation function-based features in the context of operational excitations, other nuisance parameters and added noise. The quality of the classification task is enhanced by the sufficiently large synthetic training dataset and the accuracy of the numerical solutions, reaching test classification errors below 0.1% for disjoint training set of size 7 × 103 and test set of size 3 × 103. Effects of the numerical solutions accuracy and of the sensors locations on the classification errors are also studied, showing the robustness of the proposed approach and the importance of constructing a rich and accurate representation of possible healthy and unhealthy states of interest.

scholarly journals Analysis of Tapered Timoshenko and Euler–Bernoulli Beams on an Elastic Foundation with Moving Loads

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
W. Abbas ◽  
Omar K. bakr ◽  
M. M. Nassar ◽  
Mostafa A. M. Abdeen ◽  
M. Shabrawy
Keyword(s):  
Cross Section ◽  
Differential Quadrature Method ◽  
Moving Load ◽  
Nodal Point ◽  
Point Load ◽  
Moving Loads ◽  
Cross Section Area ◽  
Section Area ◽  
The Impact ◽  
Research Studies

This research studies the vibration analysis of Euler–Bernoulli and Timoshenko beams utilizing the differential quadrature method (DQM) which has wide applications in the field of basic vibration of different components, for example, pillars, plates, round and hollow shells, and tanks. The free vibration of uniform and nonuniform beams laying on elastic Pasternak foundation will be studied under three sets of boundary conditions, that is, mixing between being simply upheld and fixed while utilizing the DQM. The natural frequencies and deflection values were produced through the examination of both beam types. Results show great concurrence with solutions from previous research studies. The impact of the nonuniform cross-section area on the vibration was contemplated. A comparison between the results from both beams is obtained. The focus of this work is on studying the deflection difference between both beam theories at different beam dimensions as well as showing the shape of rotation of the cross section while applying a nodal point load equation to simulate the moving load. The results were discussed and a general contemplation about the theories was developed.

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