A Novel Planar Tension Test of Rubber for Evaluating the Prediction Ability of the Modified Eight-Chain Model under Moderate Finite Deformation

2005 ◽  
Vol 78 (5) ◽  
pp. 879-892 ◽  
Author(s):  
Yong Xia ◽  
Yi Dong ◽  
Yuanming Xia ◽  
Wei Li

Abstract In this paper, a novel planar tension test is applied to evaluate the prediction ability of the rubber constitutive models under moderate finite deformation. Based on the automated grid method, it is found that in planar test, deformation in the center region of the specimen is homogeneous but that of the whole specimen is heterogeneous. With three dimensional (3D) finite element (FE) modeling, both the load-stretch relationship and the deformation fields predicted by various constitutive models are obtained under heterogeneous deformation state of the planar tension. By comparing FEA results to the test results, the prediction abilities of these constitutive models are evaluated. According to the results of this heterogeneous planar tension test, the modified eight-chain model is found to be more successful than the eight-chain model and the Van del Waals model in predicting the observed hyperelastic behaviors of rubber material under different deformation states.

2004 ◽  
Vol 77 (2) ◽  
pp. 230-241 ◽  
Author(s):  
Yong Xia ◽  
W. Li ◽  
Yuanming Xia

Abstract In this paper, the Automated Grid Method is applied to the uniaxial tension test of tire rubber compounds under moderate finite deformation. The test precision is improved, and the strains along axial and transversal directions are obtained simultaneously, so that compressibility of the rubber compounds can be studied directly. Based on the Eight-Chain model, and inspired with the physical idea of Van der Waals model, we put forward a modified Eight-Chain model, and generalize it into compressibility. All of the model parameters can be determined with the data obtained merely in uniaxial tension test with the Automated Grid Method, without the dependence on the data of any other test form. Fitted results show that modified Eight-Chain model can better characterize the hyperelastic mechanical behavior of incompressible and compressible rubber compounds under moderate finite deformation.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 369
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.


2015 ◽  
Author(s):  
Ahmed Swidan ◽  
Giles Thomas ◽  
Dev Ranmuthugala ◽  
Irene Penesis ◽  
Walid Amin ◽  
...  

Wetdeck slamming is one of the principal hydrodynamic loads acting on catamarans. CFD techniques are shown to successfully characterise wetdeck slamming loads, as validated through a series of controlled-speed drop tests on a three-dimensional catamaran hullform model. Simulation of water entry at constant speed by applying a fixed grid method was found to be more computationally efficient than applying an overset grid. However, the overset grid method for implementing the exact transient velocity profile resulted in better prediction of slam force magnitude. In addition the splitting force concurrent with wetdeck slam event was quantified to be 21% of the vertical slamming force.


Author(s):  
T. D. Marusich ◽  
S. Usui ◽  
R. Aphale ◽  
N. Saini ◽  
R. Li ◽  
...  

The three dimensional (3D) finite element modeling (FEM) and experimental validation of drilling are presented. The Third Wave AdvantEdge machining simulation software is applied for the FEM. It includes fully adaptive unstructured mesh generation, thermo-mechanically coupling, deformable tool-chip-workpiece contact, interfacial heat transfer across the tool-chip boundary, and constitutive models appropriate for process conditions and finite deformation analyses. The workpiece is modeled with a predrilled cone-shape blind hole to enable the early full-engagement of the whole drill point region to reduce the simulation time. Drilling experiments are conducted on the Ti-6Al-4V using a twist drill geometry. The calculated cutting force and torque are compared with the results of experiments with good agreement. Effects of process parameters on the stress and temperature distributions of the drill and workpiece are investigated in detail using the FEM.


2010 ◽  
Vol 29-32 ◽  
pp. 835-840 ◽  
Author(s):  
Zhi Peng Feng ◽  
Ji Ye Zhang ◽  
Wei Hua Zhang

As the speed of train increases, flow-induced vibration of trains passing through tunnels has become a subject of discussion, to investigate this phenomenon, a simplified geometric model and a vehicle dynamics model of a high-speed train traveling through a tunnel were built. To analyze the unsteady three-dimensional flow around the train, the 3-D, transient, viscous, compressible Reynolds-averaged Navier-Stokes equations combined with the k- two-equation turbulence model were solved with the finite volume method. The motion of the train was carried out using the technique of sliding grid method. The dynamics response of the train was obtained by means of the computational multi-body dynamics calculation. Meanwhile the running safety and riding comfort of the train were analyzed. With the numerical simulation, the variation of aerodynamic forces was obtained. The research founds that, vibration of the train increases drastically during it passing through a tunnel. The running safety and riding quality of the train are reduced greatly but they are in the safe range.


2014 ◽  
Vol 955-959 ◽  
pp. 463-470
Author(s):  
Jing Liu ◽  
Hong Wei Jiang ◽  
Chao Liu

The paper studies three-dimensional food-chain model with variable consumption rate in Chemostat. Assume the prey population's consumption rate of the nutrients is quadratic function, and the predator's consumption rate of the prey population is linear function. Use qualitative theory of ordinary differential equation to analyze the equilibrium solution of the model, especially the existence and stability of positive equilibrium solutions and Hopf bifurcation solutions. Finally,several numerical simulations illustrating the theoretical analysis are also given.


2012 ◽  
Vol 570 ◽  
pp. 1-7
Author(s):  
Yawar Jamil Adeel ◽  
Ahsan Irshad Muhammad ◽  
Azmat Zeeshan

Hyperelastic material simulation is necessary for proper testing of products functionality in cases where prototype testing is expensive or not possible. Hyperelastic material is nonlinear and more than one stress-strain response of the material is required for its characterization. The study was focused on prediction of hyperelastic behavior of rubber neglecting the viscoelastic and creep effects in rubber. To obtain the stress strain response of rubber, uniaxial and biaxial tension tests were performed. The data obtained from these tests was utilized to find the coefficients of Mooney-Rivlin, Odgen and Arruda Boyce models. Verification of the behavior as predicted by the fitted models was carried out by comparing the experimental data of a planar shear test with its simulation using the same constitutive models.


Author(s):  
David M. Pierce ◽  
Thomas E. Fastl ◽  
Hannah Weisbecker ◽  
Gerhard A. Holzapfel ◽  
Borja Rodriguez-Vila ◽  
...  

Through progress in medical imaging, image analysis and finite element (FE) meshing tools it is now possible to extract patient-specific geometries from medical images of, e.g., abdominal aortic aneurysms (AAAs), and thus to study clinically relevant problems via FE simulations. Medical imaging is most often performed in vivo, and hence the reconstructed model geometry in the problem of interest will represent the in vivo state, e.g., the AAA at physiological blood pressure. However, classical continuum mechanics and FE methods assume that constitutive models and the corresponding simulations start from an unloaded, stress-free reference condition.


Sign in / Sign up

Export Citation Format

Share Document