A Novel Implementation of the LDEM in the Ansys LS-DYNA Finite Element Code

In this paper, a novel implementation of the Lattice Discrete Element Method (LDEM) is proposed: in particular, the LDEM is implemented in the Ansys LS-DYNA finite element code. Such an implementation is employed to evaluate the fracture behaviour of sandwich panels under bending. First, the novel hybrid model proposed is validated by simulating some three-point bending experimental tests carried out at the University of Parma, and then it is used to model the fracture behaviour of sandwich panels under four-point bending. Failure mechanisms, damage locations, and load-deflection curves are numerically determined by employing such a novel model, and the results show a good agreement with the available experimental findings.

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Flexural behavior of sandwich panels with cellular wood, plywood stiffener/foam and thermoplastic composite core

Journal of Sandwich Structures & Materials ◽

10.1177/1099636217699587 ◽

2017 ◽

Vol 21 (2) ◽

pp. 784-805 ◽

Cited By ~ 8

Author(s):

Edgars Labans ◽

Kaspars Kalnins ◽

Chiara Bisagni

Keyword(s):

Mechanical Performance ◽

Sandwich Panels ◽

Experimental Tests ◽

Design Tool ◽

Thermoplastic Composite ◽

Flexural Behavior ◽

Four Point Bending ◽

Reliable Design ◽

Sufficient Strength ◽

Core Part

A series of experimental tests have been carried out on three types of novel sandwich panels mainly designed for application in lightweight mobile housing. Two types of the panels are manufactured entirely from wood-based materials while the third one presents a combination of plywood for surfaces and corrugated thermoplastic composite as a core part. All sandwich panels are designed to allow rapid one-shot manufacturing. Mechanical performance has been evaluated in four-point bending comparing the data to the reference plywood board. Additionally, finite element simulations were performed to evaluate global behavior, stress distribution and provide the basis for a reliable design tool. Obtained results show sufficient mechanical characteristics suitable for floor and wall units. Compared to a solid plywood board, sandwich alternative can reach up to 42% higher specific stiffness, at the same time maintaining sufficient strength characteristics.

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Modeling Crosstie-Ballast Load Distribution in a Railroad Trackbed using a Linear-Elastic Analysis

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120937962 ◽

2020 ◽

Vol 2674 (11) ◽

pp. 76-86

Author(s):

Brent D. Thompson ◽

David B. Clarke ◽

Jerry G. Rose

Keyword(s):

Finite Element ◽

Load Distribution ◽

Load Path ◽

University Of Kentucky ◽

Linear Elastic ◽

Modeling Methodology ◽

Modeling Software ◽

Input Variables ◽

Experimental Findings ◽

The University

This paper details a linear-elastic approach to modeling crosstie-ballast interfacial load distribution in a railroad timber crosstie trackbed using RISA 3D, a finite element modeling software. RISA results closely mirrored experimental findings with some slight deviation as discussed in the paper. The modeling methodology outlined here advances previous trackbed research at the University of Kentucky, U.S., and could be used in future trackbed finite element analyses for design or research in load path distribution and load magnitude predictability. This paper details the approach used to model a timber crosstie trackbed superstructure, including initial troubleshooting stages, and explains the derivation of program input variables. A sensitivity analysis performed on the main model determined the workable extent of linearity. The analysis also examined the effect of a poor/muddy trackbed support loading condition. The paper concludes with potential recommendations in relation to the work.

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Computational analysis of creep in ice and frozen soil based on Fish's unified model

Canadian Journal of Civil Engineering ◽

10.1139/l93-013 ◽

1993 ◽

Vol 20 (1) ◽

pp. 120-132 ◽

Cited By ~ 4

Author(s):

U. G. A. Puswewala ◽

R. K. N. D. Rajapakse

Keyword(s):

Finite Element ◽

Frozen Soil ◽

Creep Model ◽

Finite Element Code ◽

Creep Tests ◽

Frozen Soils ◽

Uniaxial Creep ◽

Media Interaction ◽

Load Tests ◽

Experimental Findings

The ability of the creep model of Fish to simulate the observed behaviour of ice and frozen soils in multiaxial stress-strain fields is investigated. The generalization of the original uniaxial creep model is made through the use of several assumptions and the multiaxial model is implemented in an iterative, time-incrementing finite element code. Sample creep parameters for the model are evaluated using previously reported uniaxial creep tests on ice and frozen silt. The finite element code is used to demonstrate the ability of the model to predict different stages of creep deformation in frozen media, by re-simulating some uniaxial creep tests on ice. Pressuremeter tests, plate load tests, and laterally loaded rigid cores (piles considered in cross section) in frozen media are simulated to demonstrate the similarity between the global response of ice and frozen soils predicted by the model and the reported experimental findings. Redistribution of stress predicted by the model is also investigated. The model is seen to possess validity in situations of attenuating as well as accelerating creep of ice and frozen soils. Key words: creep, ice, frozen soils, finite elements, structure–frozen media interaction, numerical prediction.

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Simulation of Crack Propagation in Concrete Based on Extended Finite Element Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.783.165 ◽

2018 ◽

Vol 783 ◽

pp. 165-169 ◽

Cited By ~ 2

Author(s):

Yu Xiang Tang ◽

Hong Niao Chen

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Concrete Beam ◽

Extended Finite Element Method ◽

Peak Load ◽

Experimental Tests ◽

Extended Finite Element ◽

Three Point Bending ◽

Fracture Behaviors ◽

Element Method

Fracture behaviors in concrete beam subjected to three-point bending was numerically simulated using extended finite element method (XFEM). The entire load-displacement curves and crack path obtained by numerical simulation were compared with that measured from experimental tests. Compared with the experimental results, the errors of numerical Pc and δc were smaller than 10% and the error of CMODc was lower than 2%, verifying the validity and accuracy of XFEM model. Whether a XFEM simulation or a test, the propagation direction of the main crack is toward to the upper loading point. At the peak load, the crack lengths measured by ESPI and XFEM were 93 μm and 97 μm respectively.

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Predicting the Dynamic Behaviour of Hydrobushings

Shock and Vibration ◽

10.1155/2005/748498 ◽

2005 ◽

Vol 12 (2) ◽

pp. 91-107 ◽

Cited By ~ 19

Author(s):

N. Gil-Negrete ◽

A. Rivas ◽

J. Viñolas

Keyword(s):

Finite Element ◽

Fluid Flow ◽

Dynamic Behaviour ◽

Dynamic Stiffness ◽

Experimental Tests ◽

Finite Element Code ◽

Practical Application ◽

Rubber Material ◽

Maximum Value ◽

Fluid Properties

A novel and promising approach for the prediction of the dynamic stiffness of hydrobushings is presented, combining Finite Element and CFD methods. The rubber structure of the mount is modelled in ABAQUS and the flow of fluid through the inertia track is calculated in FLUENT. The obtained results from the latter simulation are incorporated in the finite element code for the final stiffness prediction. The calculation is very sensitive to both rubber and fluid properties. The dynamic behaviour of rubber material has accurately been characterised with a new simple shear specimen in a forced non-resonant test.Satisfactory results are obtained when comparing numerical simulations to experimental tests in a practical application. Discrepancies between simulations and tests are mainly due to the simplifications assumed when creating the model. Nevertheless, stiffness of the mount is well predicted and so is the damping, although the frequency at which its maximum value is achieved is underestimated by 4–6 Hz, result that could be improved if non-stationary boundary conditions were considered when solving the fluid flow and incorporating it to the finite element code.

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Numerical and experimental investigation of the vibration of rotors with loose discs

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes1345 ◽

2009 ◽

Vol 224 (1) ◽

pp. 85-94 ◽

Cited By ~ 5

Author(s):

M Behzad ◽

M Asayesh

Keyword(s):

Mathematical Model ◽

Finite Element ◽

Experimental Tests ◽

Element Model ◽

Equation Of Motion ◽

Finite Element Code ◽

Rotating Speed ◽

Rotating Discs ◽

Gyroscopic Effects ◽

Measurement Location

In this study, the energy method has been used to develop a finite-element code for studying the effects of loose rotating discs on the rotor—bearing systems’ response. A mathematical model of the loose disc has resulted in terms similar to unbalance and gyroscopic effects in the equation of motion of the system. Results of this study show that rotor response and beating phenomena are a function of measurement location, loose disc mass and inertia, ratio of rotating speed to the speed of loose disc, and clearance between the loose disc and shaft considering constant speed for loose disc and shaft. The developed finite-element model can numerically give the response of rotors with any number of loose discs at any location with isotropic or orthotropic supports. Results of numerical calculation have been verified by experimental tests.

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Aluminium Self-Piercing Rivet's Failure: Testing and Numerical Analyses

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.541-542.1355 ◽

2014 ◽

Vol 541-542 ◽

pp. 1355-1359 ◽

Cited By ~ 1

Author(s):

Nguyen Hieu Hoang ◽

Magnus Langseth

Keyword(s):

Finite Element ◽

High Pressure ◽

Fracture Behaviour ◽

Shear Fracture ◽

Calibration Procedure ◽

Finite Element Code ◽

Failure Model ◽

Compression Tests ◽

Tension Tests ◽

Riveting Process

In the present study, the behaviour of aluminium rivets in alloy AA7278-T6 during the riveting process when used to join two aluminium plates was investigated experimentally and numerically. It was observed by Hoang et al. that a rivet in alloy AA7278-T6 may fracture in shear when undergoing high pressure during the riveting process. A damage-based failure model was adopted for studying the shear fracture behaviour of the rivet. A calibration procedure of the damage parameters was suggested based on two tests (i.e. material tension tests and rivet compression tests). The model was implemented in the finite element code LS-DYNA as a user-defined subroutine. Numerical results showed that the model seemed to be able to capture the shear fracture mode in the rivets as observed in the tests.

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Finite Element Formulation of a Piezoelectric Continuum and Performance Studies of Laminar PZT-Patch-Modules

MRS Proceedings ◽

10.1557/proc-881-cc3.3 ◽

2005 ◽

Vol 881 ◽

Cited By ~ 1

Author(s):

Monika Gall ◽

Bärbel Thielicke ◽

Christophe Poizat ◽

Sven Klinkel

Keyword(s):

Finite Element ◽

Experimental Tests ◽

Bending Test ◽

Failure Behavior ◽

Element Formulation ◽

Sensors And Actuators ◽

Mechanical Coupling ◽

Sensor Performance ◽

Four Point Bending ◽

And Performance

AbstractEfficient application of piezoelectric sensors and actuators requires extensive investigations of their loading limits, failure-behavior and life-span under service conditions. Here the performance of laminar PZT-patch-modules is studied, applying a combined approach of experimental and numerical tests. Four-point bending tests are used to evaluate the sensor performance. Linear electro-mechanical coupling is implemented in an 8-node brick user element of the research finite element code FEAP to develop a flexible FE-tool for piezoelectric problems. Comparative FE-analyses of the bending test are carried out in order to assess the capability of the implemented FEAP user element versus the commercially available FE-code ABAQUS. FE-results show good agreement with the experimental tests, different element types yield slight deviations which are discussed.

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Mechanical response and strength characteristics of aluminum honeycomb sandwich panels for infrastructure engineering

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1201/1/012046 ◽

2021 ◽

Vol 1201 (1) ◽

pp. 012046

Author(s):

S P Zaoutsos

Keyword(s):

Mechanical Behaviour ◽

Mechanical Response ◽

Sandwich Panels ◽

Strength Characteristics ◽

Analytical Models ◽

Three Point Bending ◽

Aluminum Honeycomb ◽

Experimental Findings ◽

Naval Engineering ◽

Intensive Work

Abstract The use of aluminium sandwich panels has been increased in a certain number of engineering applications from infrastructure systems and transportation to aircraft and naval engineering. Due to their structural efficiency these materials are ideal for applications where ratio of strength to weight is of crucial importance. In the current study the investigation of the strength characteristics of aluminium sandwich panels with aluminium honeycomb core and different types of skins is performed using both analytical models and experimental procedures. A series of strength tests such as tension, shear, three point bending and double cantilever beam were conducted on aluminium honeycomb-cored sandwich panel specimens with five different skins in order to examine the mode of failure and the mechanical behaviour of the structural elements. The experimental findings are compared to theoretical values while an attempt for the explanation of the mechanisms leading to failure such as buckling, delamination or debonding between core and skins is performed. The results occurring from the study are very useful for the enhancement of the mechanical behaviour of sandwich constructions, thus more intensive work must be carried out in order to understand the physical mechanisms leading to strength characteristics of sandwich panels.

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