Analysis for Tire Mold Design

1974 ◽  
Vol 2 (3) ◽  
pp. 195-210 ◽  
Author(s):  
R. A. Ridha
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Shell Element ◽  
Structural Behavior ◽  
Temperature History ◽  
Small Displacement ◽  
Toroidal Shell ◽  
Mold Design ◽  
Orthotropic Properties ◽  
Element Technique

Abstract An analysis is presented for determining tire deformation due to shrinkage. The analysis uses composite theory and the finite element technique in modeling the material properties and the structural behavior. The constant strain toroidal shell element developed by Wilson for small displacement and isotropic properties is modified for orthotropic properties which depend on the element location. Temperature history and the buildup of shrink forces during cure are determined experimentally. The shrink forces are represented by a set of equivalent loads applied at the nodes. Good correlation is obtained between calculated and experimental displacements. The analysis is applied in relating the mold shape to the final shape of the tire.

An Efficient Finite Element Modeling of Composite Stiffened Shells

2014 ◽  
Vol 553 ◽  
pp. 673-678
Author(s):  
Hamid Sheikh ◽  
Liang Huang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Degrees Of Freedom ◽  
Torsional Rigidity ◽  
Shell Element ◽  
Beam Element ◽  
Shell Elements ◽  
Element Modeling ◽  
Stiffened Shells ◽  
Element Technique

This paper presents an efficient finite element modeling technique for stiffened composite shells having different stiffening arrangements. The laminated shell skin is modeled with a triangular degenerated curved shell element having 3 corner nodes and 3 mid-side nodes. An efficient curved beam element compatible with the shell element is developed for the modeling of stiffeners which may have different lamination schemes. The formulation of the 3 nod degenerated beam element may be considered as one of the major contributions. The deformation of the beam element is completely defined in terms of the degrees of freedom of shell elements and it does not require any additional degrees of freedom. As the usual formulation of degenerated beam elements overestimates their torsional rigidity, a torsion correction factor is introduced for different lamination schemes. Numerical examples are solved by the proposed finite element technique to assess its performance.

3d Reconstruction and Nonlinear Finite Element Analysis of the Embryonic Left Ventricle

2007 ◽  
Author(s):  
Daniela Faas ◽  
Christine Buffinton ◽  
David Sedmera
Keyword(s):  
Finite Element ◽  
Left Ventricle ◽  
3D Reconstruction ◽  
Material Properties ◽  
Pressure Overload ◽  
Passive State ◽  
Stress And Strain ◽  
Element Analysis ◽  
Developing Heart ◽  
Element Technique

Changes in mechanical loading in the developing heart produce changes in morphology and mechanical material properties [1–3]. Understanding the relationship of these changes to mechanical stress and strain in the left ventricle requires a geometrically accurate model of the entire ventricle including the trabecular pattern and material property, boundary condition, and loading specification. A 3D reconstruction and finite element technique were developed to reconstruct the heart from serial confocal sections and calculate stress and strain distributions over the volume for the passive state. Control hearts and two treatments, pressure overload and pressure underload, were modeled. The results show that stresses in the trabeculae are much larger than those in the ventricular walls. Strains in the pressure-overloaded hearts were significantly smaller than in control or underloaded, indicating the stiffer material properties more than compensate for the increased internal pressure.

scholarly journals A Mixed Stress/Displacement Approach Model of Homogeneous Shells for Elastodynamic Problems

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Axel Fernando Domínguez Alvarado ◽  
Alberto Díaz Díaz
Keyword(s):  
Finite Element ◽  
Frequency Analysis ◽  
Constitutive Equations ◽  
Lagrange Equation ◽  
Shell Element ◽  
Harmonic Load ◽  
Plane Normal ◽  
Out Of Plane ◽  
Element Technique ◽  
Stress Boundary Conditions

This paper presents the development of a model of homogeneous, moderately thick shells for elastodynamic problems. The model is obtained by adapting and modifying SAM-H model (stress approach model of homogeneous shells) developed by Domínguez Alvarado and Díaz in (2018) for static problems. In the dynamic version of SAM-H presented herein, displacements and stresses are approximated by polynomials of the out-of-plane coordinate. The stress approximation coincides with the static version of SAM-H when dynamic effects are neglected. The generalized forces and displacements appearing in the approximations are the same as those involved in a classical, moderately thick shell model (CS model) but the stress approximation adopted herein is more complex: the 3D motion equations and the stress boundary conditions at the faces of the shell are verified. The generalized motion and constitutive equations of dynamic SAM-H model are obtained by applying a variant of Euler–Lagrange equation which includes pertinently Hellinger–Reissner functional. In the constitutive equations, Poisson’s effect of out-of-plane normal stresses on in-plane strains is not ignored; this is one important feature of SAM-H. To test the accuracy of dynamic SAM-H model, the following structures were considered: a hollow sphere and a catenoid. In each case, eigenfrequencies are first calculated and then a frequency analysis is performed applying a harmonic load. The results are compared to those of a CS model, MITC6 (mixed interpolation of tensorial components with 6 nodes per element) shell element calculations, and solid finite element computations. In the two problems, CS, MITC6, and dynamic SAM-H models yield accurate eigenfrequencies and eigenmodes. Nevertheless, the frequency analysis performed in each case showed that dynamic SAM-H provides much more accurate amplitudes of stresses and displacements than the CS model and the MITC6 shell finite element technique.

Refined Methods for Tire Computation

1989 ◽  
Vol 17 (4) ◽  
pp. 291-304 ◽  
Author(s):  
A. Domscheit ◽  
H. Rothert ◽  
T. Winkelmann
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Shell Element ◽  
Material Model ◽  
Nonlinear Material ◽  
Shell Elements ◽  
Is Implementation ◽  
Numerical Studies ◽  
Static Contact ◽  
Element Technique

Abstract Realistic computation of automobile tires is best achieved by modeling the whole tire with finite element methods. A numerical solution of the quasi-static contact problem for the whole tire requires a refined mesh of elements with redundant degrees of freedom when nonlinear material assumptions are considered. Both laminated shell elements and incompressible continuum elements are used here. The stiffness matrix of a shell element is determined by numerically integrating all layers within the thickness of each element. Numerical studies have been made by a finite element technique that includes shell elements and Swanson's material model, which covers large deformations. The major contribution of this paper is implementation of a composite theory that includes effects of large displacements on the stiffness into an existing element. Swanson's material law was also simplified and implemented.

Patient-Specific Finite-Element Analyses of the Proximal Femur with Orthotropic Material Properties Validated by Experiments

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Nir Trabelsi ◽  
Zohar Yosibash
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Orthotropic Material ◽  
High Order ◽  
Patient Specific ◽  
Pronounced Difference ◽  
Quantitative Computer Tomography ◽  
Fresh Frozen ◽  
Orthotropic Properties

Patient-specific high order finite-element (FE) models of human femurs based on quantitative computer tomography (QCT) with inhomogeneous orthotropic and isotropic material properties are addressed. The point-wise orthotropic properties are determined by a micromechanics (MM) based approach in conjunction with experimental observations at the osteon level, and two methods for determining the material trajectories are proposed (along organs outer surface, or along principal strains). QCT scans on four fresh-frozen human femurs were performed and high-order FE models were generated with either inhomogeneous MM-based orthotropic or empirically determined isotropic properties. In vitro experiments were conducted on the femurs by applying a simple stance position load on their head, recording strains on femurs’ surface and head’s displacements. After verifying the FE linear elastic analyses that mimic the experimental setting for numerical accuracy, we compared the FE results to the experimental observations to identify the influence of material properties on models’ predictions. The strains and displacements computed by FE models having MM-based inhomogeneous orthotropic properties match the FE-results having empirically based isotropic properties well, and both are in close agreement with the experimental results. When only the strains in the femoral neck are being compared a more pronounced difference is noticed between the isotropic and orthotropic FE result. These results lay the foundation for applying more realistic inhomogeneous orthotropic material properties in FEA of femurs.

The Plastic Ratcheting of Thin Cylindrical Shells Subjected to Axisymmetric Thermal and Mechanical Loading

1987 ◽  
Vol 109 (4) ◽  
pp. 387-393 ◽  
Author(s):  
S. Karadeniz ◽  
A. R. S. Ponter ◽  
K. F. Carter
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Mechanical Loading ◽  
Material Properties ◽  
Thermal Loading ◽  
Cylindrical Shells ◽  
Temperature Fields ◽  
Mechanical Loads ◽  
Element Technique ◽  
The Relationship

The paper discusses the relationship between material properties and structural ratcheting for thin cylindrical shells subjected to severe thermal loading. The need to understand this problem arises in the design of Sodium Cooled Fast Reactors. A sequence of shakedown solutions are presented using a finite element technique [13]. It is shown that for tubes subject to moving temperature fields, ratcheting can occur even when no mechanical loads are applied and the material strongly cyclically hardens. Only small movements are required. Stationary thermal cycling is less likely to produce ratcheting. The calculations are compared with two sets of experimental data, which serve to confirm these conclusions.

Punch Forming Simulation Analysis of U Shape Steel Plate

2013 ◽  
Vol 307 ◽  
pp. 308-311
Author(s):  
Fu Yi Cao ◽  
Xiao Wei Yin ◽  
Bao Shi Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Detailed Analysis ◽  
Material Properties ◽  
Steel Plate ◽  
Simulation Analysis ◽  
Mold Design ◽  
Spring Back ◽  
Car Industry ◽  
Forming Simulation

Punch forming is widely used in many fields such as car industry, aviation, and mechanical industry. Along with the new requirement such as velocity, efficiency, costing of punch forming, there is more and more failure appearance. For example, fracture, fold and spring back. In this paper, a detailed analysis of punch forming is done by FEM(finite element method), and the stresses of punch forming are obtained at every phase of punch. This work is very useful for mold design, punch forming parameters set and material properties test.

Bonded Flexible Pipe Model Using Macroelements

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Rodrigo Provasi ◽  
Fernando Geremais Toni ◽  
Clóvis de Arruda Martins
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Structural Behavior ◽  
Small Displacement ◽  
Relative Movement ◽  
Memory Consumption ◽  
Flexible Pipe ◽  
Pipe Model ◽  
Flexible Pipes ◽  
Compliant Behavior

Flexible pipes are structures composed by many layers that vary in composition and shapes. The structural behavior of each layer is defined by the role it must play. The construction of flexible pipes is such that the layers are unbounded, with relative movement between them. Even though this characteristic is what enables its high bending compliant behavior, if the displacements involved are small, a bonded analysis is interesting to grasp the general characteristics of the problem. The bonded hypothesis means that there is no movement relative between layers, which is fine for a small displacement analysis. It also creates a lower bound for the movement, since when considering increasingly friction coefficient values, it tends to the bonded situation. The main advantage of such hypothesis is that the system becomes linear, leading to fast solving problems (when compared to full frictional analysis) and giving insights to the pipe behavior. The authors have previously developed a finite element based one called macroelements. This model enables a fast-solving problem with less memory consumption when compared to multipurpose software. The reason behind it is the inclusion of physical characteristics of the problem, enabling the reduction in both number of elements and memory used and, since there are less elements and degrees-of-freedom, faster solved problems. In this paper, the advantages of such model are shown by using examples that are representative of a simplified, although realistic, flexible pipe. Comparisons between the macroelement model and commercial software are made to show its capabilities.

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