Advanced finite-element modelling of a 32-panel soccer ball

2007 ◽  
Vol 221 (11) ◽  
pp. 1309-1319 ◽  
Author(s):  
D S Price ◽  
R Jones ◽  
A R Harland
Keyword(s):  
Finite Element ◽  
Polyester Fibre ◽  
Material Model ◽  
Element Model ◽  
Impact Testing ◽  
Material Anisotropy ◽  
Soccer Ball ◽  
Impact Characteristics ◽  
The Impact ◽  
Kinetic Energy Loss

The current paper details the development of a finite-element model of a manually stitched, textile reinforced 32-panel soccer ball used in elite competition. The model included material anisotropy, a stiffer region representative of the polyester fibre based stitching, and a latex bladder membrane which was pressurized through inflation. A stiffness proportional damping coefficient was included within the material model to describe kinetic energy loss characteristics. The model was validated through experimental impact testing at speeds representative of play. It was found that the combined effects of material anisotropy, panel stitching, and panel configuration had a profound effect on the impact characteristics of the ball.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

FE Modeling of the Three-Layer Human Carotid Artery Under Impact Loadings

2007 ◽  
Author(s):  
Aihong Zhao ◽  
Ken Digges ◽  
Mark Field ◽  
David Richens
Keyword(s):  
Finite Element ◽  
Carotid Artery ◽  
Model Simulation ◽  
Material Model ◽  
Element Model ◽  
Traumatic Rupture ◽  
Aortic Tissue ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
The Impact

Blunt traumatic rupture of the carotid artery is a rare but life threatening injury. The histology of the artery is key to understanding the aetiology of this injury. The carotid artery is composed of three layers known as the tunica intima, media, and adventitia, with distinct biomechanical properties. In order to examine the behaviour of the carotid artery under external load we have developed a three layer finite element model of this vessel. A rubber-like material model from LS-DYNA was selected for the FE model. The Arbitrary-Lagrangian Eulerian (ALE) approach was adopted to simulate the interaction between the fluid (blood) and the structure (carotid). To verify the FE model, the impact bending tests are simulated using this FE model. Simulation results agree with tests results well. Furthermore, the mechanical behaviour of carotid artery tissues under impact loading were revealed by the simulations. The results provide a basis for a more in-depth investigation of the carotid artery in vehicle crashes. In addition, it provides a basis for further work on aortic tissue finite element modeling.

Spin generation during an oblique impact of a compliant ball on a non-compliant surface

2011 ◽  
Vol 226 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Tom Allen ◽  
James Ibbitson ◽  
Steve Haake
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Oblique Impact ◽  
Tennis Ball ◽  
Compliant Surface ◽  
Oblique Impacts ◽  
Impact Characteristics ◽  
The Impact ◽  
The Finite Element Model

Oblique impacts between a ball and surface are a key part of many sports. Previous work has shown that a ball can slide, over-spin or roll at the end of an impact, depending on impact conditions. Inbound spin ratio was analysed to determine if it could be used to identify what is likely to happen at the end of impact for all sports regardless of surface, ball type, impact velocity, angle and spin. A predictive model, in the form of a finite element model, of a tennis ball was validated against experimental data for oblique impacts with inbound spin ratios in the range of –1 to 1. Spin ratio is defined as the product of the ball’s angular velocity and radius divided by the centre of mass velocity tangential to the surface. The finite element model was then used to determine the effect of impact conditions and ball parameters on outbound spin ratio. The study showed that for constant inbound spin ratio, outbound spin ratio was dependent on inbound velocity and angle. For constant inbound velocity and angle, decreasing the mass and increasing the stiffness of the ball through a change in material properties resulted in an increase in the maximum outbound spin ratio. Inbound spin ratio can be used to predict how a ball will rebound from a surface; however, inbound velocity and angle must be constant. Spin ratio can therefore be used to compare the impact characteristics for different ball and surface scenarios.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Investigation on the shaft voltage generation of large synchronous turboalternators

2020 ◽  
Vol 39 (5) ◽  
pp. 1145-1156
Author(s):  
Kevin Darques ◽  
Abdelmounaïm Tounzi ◽  
Yvonnick Le-menach ◽  
Karim Beddek
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Short Circuit ◽  
Element Model ◽  
Stator Winding ◽  
Content Type ◽  
Voltage Generation ◽  
The Impact ◽  
Investigation Process ◽  
Circulating Currents

Purpose This paper aims to go deeper on the analysis of the shaft voltage of large turbogenerators. The main interest of this study is the investigation process developed. Design/methodology/approach The analysis of the shaft voltage because of several defects is based on a two-dimensional (2D) finite element modeling. This 2D finite element model is used to determine the shaft voltage because of eccentricities or rotor short-circuit. Findings Dynamic eccentricities and rotor short circuit do not have an inherent impact on the shaft voltage. Circulating currents in the stator winding because of defects impact the shaft voltage. Originality/value The original value of this paper is the investigation process developed. This study proposes to quantify the impact of a smooth stator and then to explore the contribution of the real stator winding on the shaft voltage.

Behavior of Structures Using Simple Plastic Hinge Theory

1994 ◽  
Author(s):  
Ramakrishnan Maruthayappan ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cantilever Beam ◽  
Reliable Method ◽  
Plastic Hinge ◽  
Element Model ◽  
Finite Element Models ◽  
Computational Program ◽  
Hinge Model ◽  
The Impact

Abstract The behavior of structures under the impact or crash situations demands an efficient modeling of the system for its behavior to be predicted close to practical situations. The various formulations that are possible to model such systems are spring mass models, finite element models and plastic hinge models. Of these three techniques, the plastic hinge theory offers a more accurate model compared to the spring mass formulation and is much simpler than the finite element models. Therefore, it is desired to model the structure using plastic hinges and to use a computational program to predict the behavior of structures. In this paper, the behavior of some simple structures, ranging from an elementary cantilever beam to a torque box are predicted. It is also shown that the plastic hinge theory is a reliable method by comparing the results obtained from a plastic hinge model of an aviation seat structure with that obtained from a finite element model.

Simulation Analysis of Secondary-Load Rc Square Columns Strengthened with IFRP

2014 ◽  
Vol 501-504 ◽  
pp. 578-582
Author(s):  
Liang Hsu ◽  
Ming Long Hu ◽  
Jun Zhi Zhang
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Element Model ◽  
Fiber Reinforced Polymer ◽  
Experimental Result ◽  
Compression Process ◽  
Reinforced Polymer ◽  
Secondary Load ◽  
The Impact ◽  
The Finite Element Model

Considering secondary load, simulate the axial compression process of reinforced concrete square columns strengthened with igneous rock fiber reinforced polymer with Abaqus. Make a comparison between the simulation result and experimental result. The finite-element model can simulate the experiment preferably. And the impact of lagged strain is very obvious.

Additional Damping Conditions Analysis and Calculation for Exciting Force and External Load

2013 ◽  
Vol 579-580 ◽  
pp. 507-511
Author(s):  
Yi Xiang Liu ◽  
Yong Mei Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Structure Design ◽  
Exciting Force ◽  
Reduction Gear ◽  
Solid Model ◽  
Gear Noise ◽  
Force Reduction ◽  
And Control ◽  
The Impact

This paper firstly starting mechanism of vibration and noise from gear, gear noise mechanism is explained, and analyze the factors and the impact of noise on the gear reducer. Secondly, the establishment of a complete solid model of gear reducer and reducer model for finite element model, the reduction gear box gear reducer of modal analysis and finite element modal calculation, and points out the dynamic analysis of structure, size and weight factor is proportional to the reciprocal of the modal frequencies of each mode is the with the frequency is low, that is, the greater the weight. Once again, the main measure of load and control of gear noise of gear is analyzed, including the calculation, for exciting force reduction gear reducer gear load computation. The analysis and calculation are the theoretical basis of gear structure design and its performance evaluation.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

scholarly journals Analysing Random Vibration of KLT Box during Transporting by Finite Element Method

10.29007/b1th ◽  
2022 ◽  
Author(s):  
Cong Hoa Vu ◽  
Ngoc Thien Ban Dang
Keyword(s):  
Finite Element ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Automotive Industry ◽  
Random Vibration ◽  
Element Model ◽  
Vibration Testing ◽  
Time Data ◽  
Power Spectral ◽  
The Impact

Today, freight is an extremely important industry for the world we are living. Fast transportation, large volume...will optimize the cost, time and effort. Besides, ensuring the products safety is a matter of concern. During transporting, it is inevitable that the vibration caused by the engine, rough road surface...the cargo inside can be damaged. Automobile industries have prime importance to vibration testing. Sine vibration testing is performed when we have been given with only one frequency at given time instant. Trend to perform random vibration testing has been increased in recent times. As random vibration considers all excited frequencies in defined spectrum at known interval of time, it gives real-time data of vibration severities. The vibration severity is expressed in terms of Power Spectral Density (PSD). KLT box is an industrial stacking container conforming to the VDA 4500 standard that was defined by German Association of the Automotive Industry (VDA) for the automotive industry. The aim of this paper is study about random vibration and power spectral density analysis, how it can be used to predict the impact of hash road to the KLT box on container / truck during transportation. Finite element model is developed in ANSYS, modal analysis and random vibration analysis were done.

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