Cornering characteristics of a truck tire on wet surface using finite element analysis and smoothed-particle hydrodynamics

2018 ◽  
Vol 6 (4) ◽  
pp. 1567-1576 ◽  
Author(s):  
Zeinab El-Sayegh ◽  
Moustafa El-Gindy
2021 ◽  
Vol 18 (185) ◽  
Author(s):  
S. Mostafa Mousavi J. S. ◽  
Danial Faghihi ◽  
Kelsey Sommer ◽  
Mohammad M. S. Bhurwani ◽  
Tatsat R. Patel ◽  
...  

Stent retriever thrombectomy is a pre-eminent treatment modality for large vessel ischaemic stroke. Simulation of thrombectomy could help understand stent and clot mechanics in failed cases and provide a digital testbed for the development of new, safer devices. Here, we present a novel, in silico thrombectomy method using a hybrid finite-element analysis (FEA) and smoothed particle hydrodynamics (SPH). Inspired by its biological structure and components, the blood clot was modelled with the hybrid FEA–SPH method. The Solitaire self-expanding stent was parametrically reconstructed from micro-CT imaging and was modelled as three-dimensional finite beam elements. Our simulation encompassed all steps of mechanical thrombectomy, including stent packaging, delivery and self-expansion into the clot, and clot extraction. To test the feasibility of our method, we simulated clot extraction in simple straight vessels. This was compared against in vitro thrombectomies using the same stent, vessel geometry, and clot size and composition. Comparisons with benchtop tests indicated that our model was able to accurately simulate clot deflection and penetration of stent wires into the clot, the relative movement of the clot and stent during extraction, and clot fragmentation/embolus formation. In this study, we demonstrated that coupling FEA and SPH techniques could realistically model stent retriever thrombectomy.


Author(s):  
Zeinab El-Sayegh ◽  
Moustafa El-Gindy

This paper focuses on the modelling and prediction of truck tyre–snow interaction to compute tyre motion resistance coefficient. The off-road truck tyre size 315/80R22.5 is modelled using finite element analysis and validated in static and dynamic response against published measured data. The snow is modelled using smoothed particle hydrodynamics technique and hydrodynamic-elastic-plastic material and then calibrated against physical measurements provided by published terramechanics data. The contact algorithm implemented is the node-symmetric node-to-segment contact with edge treatment. The rolling resistance coefficient is also known as the motion resistance coefficient of the truck tyre–snow interaction and is computed for several operating conditions including the vertical load, inflation pressure, tyre longitudinal speed, and snow depth. The influence of the above-mentioned operating conditions on the truck tyre motion resistance coefficient is examined and discussed.


2013 ◽  
Vol 61 (1) ◽  
pp. 111-121 ◽  
Author(s):  
T. Jankowiak ◽  
T. Łodygowski

Abstract The paper considers the failure study of concrete structures loaded by the pressure wave due to detonation of an explosive material. In the paper two numerical methods are used and their efficiency and accuracy are compared. There are the Smoothed Particle Hydrodynamics (SPH) and the Finite Element Method (FEM). The numerical examples take into account the dynamic behaviour of concrete slab or a structure composed of two concrete slabs subjected to the blast impact coming from one side. The influence of reinforcement in the slab (1, 2 or 3 layers) is also presented and compared with a pure concrete one. The influence of mesh density for FEM and the influence of important parameters in SPH like a smoothing length or a particle distance on the quality of the results are discussed in the paper


Author(s):  
Ranvir Dhillon ◽  
Moustafa El-Gindy ◽  
Rustam Ali ◽  
David Philipps ◽  
Fredrik Öijer ◽  
...  

The rapid progression of computational power and development of non-mesh particle modeling techniques provides solutions to problems which are not accurately modeled using traditional finite element analysis techniques. The field of soft soil modeling has been pressing on in recent years and the smoothed particle hydrodynamics (SPH) modeling method in PAM-CRASH provides opportunity for further advancement in accuracy. This research focuses on the development of soft soil models using SPH with verification using pressure-sinkage and shear strength criterion. Soil model parameters such as geometry and contact model are varied to determine the effect of the parameters on the behaviour of the soft soil and relationships are developed. The developed virtual soil models are compared against existing soils to determine which soils are accurately modeled and further refinements are made to validate the models with existing empirical data.


Author(s):  
Chinmay S. Avachat ◽  
Harish P. Cherukuri

Modeling machining processes with conventional finite element methods (FEM) is challenging due to the severe deformations that occur during machining, complex frictional conditions that exist between the cutting tool and the workpiece, and the possibility of self contact due to chip curling. Recently, the Smoothed Particle Hydrodynamics (SPH) method has emerged as a potential alternative for modeling machining processes due to its ability to handle severe deformations while avoiding mass and energy losses encountered by traditional FEM. The method has been implemented in several commercial finite element packages such as ABAQUS and LS-DYNA for solving problems involving localized severe deformations. Numerous control parameters are present in a typical SPH formulation. The purpose of this work is to evaluate the effect of the three most important parameters, namely, the smoothing length, particle density, and the type of SPH formulation. The effects of these parameters on the chip morphology and stress distribution in the context of orthogonal machining of AISI 1045 steel are investigated. The LS-DYNA finite element package along with Johnson-Cook material model is used for this purpose. Results from the parametric study are presented and compared with the previously reported results in the literature. In addition, the sensitivity of chip morphology and stresses to Johnson-Cook parameters for AISI 1045 steel is also investigated by considering five different sets of values reported in the literature for this steel.


2019 ◽  
Vol 141 (8) ◽  
Author(s):  
A. Ersin Dinçer ◽  
Abdullah Demir ◽  
Zafer Bozkuş ◽  
Arris S. Tijsseling

Abstract In this study, a combination of the smoothed particle hydrodynamics (SPH) and finite element method (FEM) solving the complex problem of interaction between fluid with free surface and an elastic structure is studied. A brief description of SPH and FEM is presented. Contact mechanics is used for the coupling between fluid and structure, which are simulated with SPH and FEM, respectively. In the proposed method, to couple mesh-free and mesh-based methods, fluid and structure are solved together by a complete stiffness matrix instead of iterative predictive–corrective or master–slave methods. In addition, fully dynamic large-deformation analysis is carried out in FEM by taking into account mass and damping of the elastic structure. Accordingly, a two-dimensional fluid–structure interaction (FSI) code is developed and validated with two different experiments available in the literature. The results of the numerical method are in good agreement with the experiments. In addition, a novel laboratory experiment on a dam break problem with elastic gate in which the length of the initial water column is larger than its height is conducted. The main difference between the previous experiments and the one conducted in this study is that an upward water motion parallel to the elastic gate is observed at the upstream side of the gate. This motion is captured with the numerical method.


1987 ◽  
Vol 15 (2) ◽  
pp. 134-158 ◽  
Author(s):  
N-T. Tseng

Abstract Axisymmetric analysis of an inflated tire rotating with constant angular speed can be used to simulate two loading conditions of a tire during its service life: (1) a freely rotating tire on an automobile that is stuck in snow or mud and (2) the top region of a rolling loaded tire, where footprint loading has little influence on the distribution of its stresses and strains. The equations of motion for a freely rotating deformable body with constant angular speed have been derived and implemented into a finite element code developed in-house. The rotation of a thin disk was used to check the validity of the implemented formulation and coding. Excellent agreement between the numerical and the analytical results was obtained. A cast tire, a radial automobile tire, and a radial truck tire, were then analyzed by the new finite element procedure. The tires were inflated and rotated at speeds up to 241 km/h (150 mph). The elastomers in these tires were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. Each ply was simulated by its equivalent orthotropic material model. The finite element predictions agreed well with the available experimental measurements. Significant changes in interply shear strain at the belt edge, the bead load, and the crown cord loads of plies were observed in the finite element analysis. These phenomena suggest three possible failure modes in freely rotating tires, i.e. belt edge separation, bead breakage, and belt failure at crown region.


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