A comparative study of static and dynamic properties of honeycomb non-pneumatic wheels and a pneumatic wheel

2021 ◽  
pp. 095440702110079
Author(s):  
Zhou Zheng ◽  
Subhash Rakheja ◽  
Ramin Sedaghati
Keyword(s):  
Dynamic Properties ◽  
Three Dimensional ◽  
Fe Model ◽  
Vertical Force ◽  
Wheel Load ◽  
Pneumatic Wheel ◽  
Longitudinal Stiffness ◽  
Dimensional Finite Element ◽  
Reported Data ◽  
Three Dimensional Finite Element

Three-dimensional finite element (FE) models of the honeycomb NPWs with three different spokes’ configurations, realized by varying the cell angle, were formulated. The validity of the proposed NPW FE models was demonstrated by comparing the predicted wheel responses with the reported data. A FE model of the pneumatic wheel of identical size was also formulated and verified on the basis of the measured vertical force-deflection and cornering properties. The verified NPW models were subsequently employed to study their feasibility through comparisons of in-plane as well as out-of-plane properties with those of the pneumatic wheel. The influences of the cell angle and normal wheel load on the static and dynamic properties of the NPWs were also investigated. The results showed load-dependent longitudinal stiffness of the wheel due to strong coupling between radial and longitudinal deformations of the honeycomb spokes. The lateral stiffness, however, was observed to be load-independent due to negligible coupling between radial and lateral deformations of the spokes. The spokes of the honeycomb NPWs could thus be easily tuned to achieve vertical and longitudinal stiffness comparable to those of the reference pneumatic wheel. The lateral and cornering stiffness of the NPWs with the planar spokes, however, were substantially higher, irrespective of the spokes’ configuration considered. The significantly higher cornering stiffness resulted in rapid saturation of the cornering force of the NPWs at side-slip angles about 1.1°, which is likely to cause lateral sliding of the wheels and potential loss of directional control under higher side slip conditions.

scholarly journals Condensation method in practical modal analysis of hull vibration with application of 3D FE model

2019 ◽  
pp. 162-169
Author(s):  
Valeriy Sutyrin
Keyword(s):  
Modal Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Fe Model ◽  
Structural Elements ◽  
Natural Vibrations ◽  
Condensation Method ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Analytical Approaches

This paper gives modal analysis results for mid-body of a refrigerator carrier ship by means of combined three-dimensional finite-element model with 1.5 million DOF. The study estimates the error of modal analysis for the ship structure if its boundary conditions are specified in advance, i.e. approximately, as well as analyses the gain in time offered by structuring the analytical model as per reduction (condensation) method. Analytical approaches thus transformed can be successfully applied in filtering lower frequencies and modes of natural vibrations for structural elements and joints of hull in the direct vicinity of exciting force application points.

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

On the Axial Holding Capacity of Torpedo Bases in Clay

2017 ◽  
Author(s):  
José Renato M. de Sousa ◽  
Rachel G. B. C. Genzani ◽  
Elisabeth C. Porto ◽  
Alexandre T. Borges ◽  
Emmanuel F. Nogueira ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Free Fall ◽  
Fe Model ◽  
Well Drilling ◽  
Soft Clays ◽  
Axial Capacity ◽  
Accurate Design ◽  
Dimensional Finite Element ◽  
One Year ◽  
Three Dimensional Finite Element

A torpedo base is a type of conductor casing that embeds into the seabed mainly by free fall using its own weight as driving energy. One of the advantages of this concept is to install the conductor casing before the dynamic positioned (DP) drillship arrival at the location. This reduces the time of the well drilling leading to significant cost saving. However, the need to withstand the challenging loads of the ultra-deep water scenarios pushed the typical torpedo base design to its limit and, consequently, modifications to its original geometry and more accurate design models are needed. Therefore, in this work, a new torpedo base, designed to sustain high axial loads in very soft clays, is analyzed with a three-dimensional finite element (FE) model. This model accounts for the setup-effects of the soil with the use of a previously proposed analytical approach to estimate the stress state of the soil at any time after the installation of the base. The results obtained indicate that the axial holding capacity of the base varies along time. The holding capacity increase rapidly at the beginning of the installation, but this rate reduces after the first days. Depending on soil characteristics, full axial capacity may be reached more than one year after the installation of the base. Moreover, the use of more than four fins welded to the shaft of the conductor casing modifies the shear zone along the base, but does not contribute to a significant increase in the axial holding capacity.

Backcalculation of Thermally Deformed Concrete Pavements

2000 ◽  
Vol 1716 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Samir N. Shoukry
Keyword(s):  
Thermal Gradient ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Slab Thickness ◽  
Fe Model ◽  
Concrete Pavements ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Falling Weight

Nonlinear explicit three-dimensional finite element (3-D FE) modeling is used to investigate the performance of the falling weight deflectometer (FWD) test in the evaluation of layer moduli of jointed plain concrete pavements (JPCP) subjected to nonlinear thermal gradient through the slab thickness. Concrete slab separation from the base, in-plane friction at the concrete-base interface, the gravitational forces, and the interface characteristics between dowel bars and surrounding concrete are all represented in the 3-D FE model. Experimental verification of the model is obtained through comparison of the 3-D FE generated response to ( a) the FWD measured deflection basin and ( b) the measured response of an instrumented rigid pavement section located in Ohio to a loaded truck moving at 21.8 m/s (48 mph). Several cases of linear and nonlinear thermal gradients are applied to the model, and deflection basins are obtained. Two backcalculation programs, MODULUS 5.0 and EVERCALC 4.0, are used for prediction of the layer moduli in each case, and the values are compared. The results indicate that thermal curling of the slab due to negative thermal gradient has little effect on the accuracy of backcalculated moduli. Warping of the slab due to positive thermal gradient greatly influences the measured FWD deflection basin and leads to significant errors in the backcalculated moduli. These errors may be minimized if the time an FWD test is conducted falls between the late afternoon and midmorning (from 5:30 p.m. to 9:30 a.m. during summer in West Virginia).

Residual Stress Prediction for Non-Axisymmetric Vessel Penetration Welds

2008 ◽  
Author(s):  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Measurement Data ◽  
Fe Model ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Stress Prediction ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Residual stress distribution in an oblique nozzle jointed to a vessel with J-groove welds was analyzed using a three-dimensional finite element method. All welding passes were considered in a 180-degree finite element (FE) model with symmetry. Temperature and stress were modeled for simultaneous bead laying. To determine residual stress distributions at the welds experimentally, a mock-up specimen was manufactured. The analytical results show good agreement with the experimental measurement data, indicating that FE modeling is valid.

Three Dimensional Finite Element Analyses of Welding Residual Stresses of a Repaired Weld

2018 ◽  
Author(s):  
Mingya Chen ◽  
Weiwei Yu ◽  
Fei Xue ◽  
Francis Ku ◽  
Zhilin Chen ◽  
...  
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Nuclear Power ◽  
Power Plants ◽  
Three Dimensional ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
Surge Line ◽  
Line Slope ◽  
Three Dimensional Finite Element

The objective of this study is to correct installation non-conformance of a surge line using the excavation and re-weld method which is widely used in nuclear power plants. The surge line with a backslope was not at the required design level after initial installation. In order to solve the problem, a repairing technology is shown as follows: the weld was successively excavated and welded again while the surge line slope was corrected with the help of jacks. Because many of the degradation mechanisms relevant to power plant components can be accelerated by the presence of welding residual stresses (WRS), the WRS caused by the repairing process need to be studied. In this paper, the WRS simulation technique employed in this project is sophisticated. It utilizes a 3-D finite element (FE) model, and simulates the weld sequencing and excavation. Moreover, the WRS simulation performed in this project not only uses the un-axisymmetric model, but also considers the deformation caused by the external jacking loads. The results show that the repairing process is effective, and strain damage induced by the welding repair is also acceptable.

Three-Dimensional Finite Element Analysis of Skin-Pass Rolling and New Models for Process Control

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Sung Jin Yoon ◽  
Tae Jin Shin ◽  
Jae Sang Lee ◽  
Sang Moo Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Coupled Analysis ◽  
Stress Profile ◽  
Fe Model ◽  
Element Analysis ◽  
Skin Pass ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper describes in detail the deformation behavior of the rolls and strip predicted from the three-dimensional finite element analysis of skin-pass rolling. The predictions are made on the basis of the coupled analysis of elastic deformation of the rolls and elastic–plastic deformation of the strip. Predictions from the proposed finite element (FE) model are compared with experimental data from laboratory-scale cold rolling mills. Then, proposed are models for the prediction of the roll force profile and for the prediction of the residual stress profile. The prediction accuracy of the models is examined through comparison with the predictions from the FE model.

scholarly journals A Three-Dimensional Finite-Element Model of a Human Dry Skull for Bone-Conduction Hearing

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Namkeun Kim ◽  
You Chang ◽  
Stefan Stenfelt
Keyword(s):  
Finite Element ◽  
Bone Conduction ◽  
Three Dimensional ◽  
Human Head ◽  
Element Model ◽  
Fe Model ◽  
Lateral Direction ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

A three-dimensional finite-element (FE) model of a human dry skull was devised for simulation of human bone-conduction (BC) hearing. Although a dry skull is a simplification of the real complex human skull, such model is valuable for understanding basic BC hearing processes. For validation of the model, the mechanical point impedance of the skull as well as the acceleration of the ipsilateral and contralateral cochlear bone was computed and compared to experimental results. Simulation results showed reasonable consistency between the mechanical point impedance and the experimental measurements when Young’s modulus for skull and polyurethane was set to be 7.3 GPa and 1 MPa with 0.01 and 0.1 loss factors at 1 kHz, respectively. Moreover, the acceleration in the medial-lateral direction showed the best correspondence with the published experimental data, whereas the acceleration in the inferior-superior direction showed the largest discrepancy. However, the results were reasonable considering that different geometries were used for the 3D FE skull and the skull used in the published experimental study. The dry skull model is a first step for understanding BC hearing mechanism in a human head and simulation results can be used to predict vibration pattern of the bone surrounding the middle and inner ear during BC stimulation.

A three-dimensional finite element model from computed tomography data: A semi-automated method

2001 ◽  
Vol 215 (2) ◽  
pp. 203-212 ◽  
Author(s):  
P M Cattaneo ◽  
M Dalstra ◽  
L H Frich
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Three Dimensional ◽  
Patient Specific ◽  
Fe Model ◽  
Element Analysis ◽  
Automated Method ◽  
Bone Properties ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element analysis is one of the best ways to assess stress and strain distributions in complex bone structures. However, accuracy in the results may be achieved only when accurate input information is given. A semi-automated method to generate a finite element (FE) model using data retrieved from computed tomography (CT) was developed. Due to its complex and irregular shape, the glenoid part of a left embalmed scapula bone was chosen as working material. CT data were retrieved using a standard clinical CT scanner (Siemens Somatom Plus 2, Siemens AG, Germany). This was done to produce a method that could later be utilized to generate a patient-specific FE model. Different methods of converting Hounsfield unit (HU) values to apparent densities and subsequently to Young's moduli were tested. All the models obtained were loaded using three-dimensional loading conditions taken from literature, corresponding to an arm abduction of 90°. Additional models with different amounts of elements were generated to verify convergence. Direct comparison between the models showed that the best method to convert HU values directly to apparent densities was to use different equations for cancellous and cortical bone. In this study, a reliable method of determining both geometrical data and bone properties from patient CT scans for the semi-automated generation of an FE model is presented.

Simulation-Based Study of Impact Energy Absorption in American Football Helmet

2016 ◽  
Author(s):  
Seyed Saeed Ahmadisoleymani ◽  
James Yang ◽  
Andrew Schmit ◽  
Jahan Rasty
Keyword(s):  
Three Dimensional ◽  
American Football ◽  
Fe Model ◽  
Revolution Speed ◽  
Football Helmet ◽  
Simulation Based ◽  
Dimensional Finite Element ◽  
Energy Absorbing ◽  
Three Dimensional Finite Element

Concussion injury limits the American football player’s career life and causes several long term problems. In order to limit its severity and frequency, various helmets have been designed to protect player’s head. This absorbency is mainly achieved by the padding system inside the helmet which includes energy absorbing and comfort foams and inflatable air surrounding the foams. In a recent study an experiment was performed on a Riddell Youth Revolution Speed helmet to analyze the effect of the head size on capability of the helmet in attenuating the impacts. It was found that headform size would affect the helmet performance. In the current study, a three dimensional finite element (FE) model has been developed based on the above mentioned experiment. The purpose of this study is to develop and validate the FE model based on the experimental results, regarding the effect of headform size on performance of the helmet.

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