A Penetration-Based Finite Element Method for Hyperelastic 3D Biphasic Tissues in Contact: Part 1-Derivation of Contact Boundary Conditions

2005 ◽  
Vol 128 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Kerem Ün ◽  
Robert L. Spilker

In this study, we extend the penetration method, previously introduced to simulate contact of linear hydrated tissues in an efficient manner with the finite element method, to problems of nonlinear biphasic tissues in contact. This paper presents the derivation of contact boundary conditions for a biphasic tissue with hyperelastic solid phase using experimental kinematics data. Validation of the method for calculating these boundary conditions is demonstrated using a canonical biphasic contact problem. The method is then demonstrated on a shoulder joint model with contacting humerus and glenoid tissues. In both the canonical and shoulder examples, the resulting boundary conditions are found to satisfy the kinetic continuity requirements of biphasic contact. These boundary conditions represent input to a three-dimensional nonlinear biphasic finite element analysis; details of that finite element analysis will be presented in a manuscript to follow.

2014 ◽  
Vol 635-637 ◽  
pp. 549-554
Author(s):  
Yu Feng Ding ◽  
Wei Fang ◽  
De Gang Wang ◽  
Bu Yun Sheng

Finite element method is widely used in steam turbine impeller blade subsystem strength analysis aspect, but because of the complicated working environment, the steam turbine has taken different handling of loads and boundary conditions when using finite element analysis method. In this paper, Static strength of the "215mm" of 135 MW steam turbine standard blade was calculated by using traditional calculation method and finite element method. By comparing two kinds of analysis results, the work load and boundary conditions were revised, which ensured the credibility of the result of the finite element analysis; According to the analysis results of stress, concentration phenomenon was obvious, then the blade root was optimized and the optimization result was excellent.


1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1388
Author(s):  
Daniele Oboe ◽  
Luca Colombo ◽  
Claudio Sbarufatti ◽  
Marco Giglio

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.


Author(s):  
Jiemin Liu ◽  
Guangtao Ma

A typical ground imitating tank is analyzed regarding it as the thin-walled structure composed of plates (skins) and beams (reinforcement) using finite element method (FEM). Through moving the location of reinforcements, make the skins close with the flanges of the reinforcements in order to imitate actually the connection of the skins and the reinforcements. The thickness of plates, the size and the geometry shape and the location of reinforcements are taken as parameters to be optimized. In calculation, not only consider effects of the oil-weight, the extra-pressure in tank and the dead weight of the tank on the stresses and displacements of the tank, but also analyze the effects of the inertia forces produced due to the rotation of the tank on the stresses and displacements. Displacement, stress and deformation distributions of the ground imitating tank under the three typical flying postures imitated are given.


Author(s):  
Liang Wang ◽  
Xue Zhang ◽  
Filippo Zaniboni ◽  
Eugenio Oñate ◽  
Stefano Tinti

AbstractNotwithstanding its complexity in terms of numerical implementation and limitations in coping with problems involving extreme deformation, the finite element method (FEM) offers the advantage of solving complicated mathematical problems with diverse boundary conditions. Recently, a version of the particle finite element method (PFEM) was proposed for analyzing large-deformation problems. In this version of the PFEM, the finite element formulation, which was recast as a standard optimization problem and resolved efficiently using advanced optimization engines, was adopted for incremental analysis whilst the idea of particle approaches was employed to tackle mesh issues resulting from the large deformations. In this paper, the numerical implementation of this version of PFEM is detailed, revealing some key numerical aspects that are distinct from the conventional FEM, such as the solution strategy, imposition of displacement boundary conditions, and treatment of contacts. Additionally, the correctness and robustness of this version of PFEM in conducting failure and post-failure analyses of landslides are demonstrated via a stability analysis of a typical slope and a case study on the 2008 Tangjiashan landslide, China. Comparative studies between the results of the PFEM simulations and available data are performed qualitatively as well as quantitatively.


2008 ◽  
Vol 606 ◽  
pp. 103-118 ◽  
Author(s):  
Jing Zhe Pan ◽  
Ruo Yu Huang

Predicting the sintering deformation of ceramic powder compacts is very important to manufactures of ceramic components. In theory the finite element method can be used to calculate the sintering deformation. In practice the method has not been used very often by the industry for a very simple reason – it is more expensive to obtain the material data required in a finite element analysis than it is to develop a product through trial and error. A finite element analysis of sintering deformation requires the shear and bulk viscosities of the powder compact. The viscosities are strong functions of temperature, density and grain-size, all of which change dramatically in the sintering process. There are two ways to establish the dependence of the viscosities on the microstructure: (a) by using a material model and (b) by fitting the experimental data. The materials models differ from each other widely and it can be difficult to know which one to use. On the other hand, obtaining fitting functions is very time consuming. To overcome this difficulty, Pan and his co-workers developed a reduced finite element method (Kiani et. al. J. Eur. Ceram. Soc., 2007, 27, 2377-2383; Huang and Pan, J. Eur. Ceram. Soc., available on line, 2008) which does not require the viscosities; rather the densification data (density as function of time) is used to predict sintering deformation. This paper provides an overview of the reduced method and a series of case studies.


1980 ◽  
Vol 47 (2) ◽  
pp. 377-382 ◽  
Author(s):  
K. Miya ◽  
T. Takagi ◽  
Y. Ando

Some corrections have been made hitherto to explain the great discrepancy between experimental and theoretical values of the magnetoelastic buckling field of a ferromagnetic beam plate. To solve this problem, the finite-element method was applied. A magnetic field and buckling equations of the ferromagnetic beam plate finite in size were solved numerically assuming that the magnetic torque is proportional to the rotation of the plate and by using a disturbed magnetic torque deduced by Moon. Numerical and experimental results agree well with each other within 25 percent.


2012 ◽  
Vol 271-272 ◽  
pp. 1291-1295
Author(s):  
Cai Jun Liu

By use of finite element method to analyze the strength of 6-wing synchronous rotor, and illustrate the change of parameters regarding strain, stress and displacement etc. so as to visually see whether the designed rotor will reach the design requirements; meanwhile, through structural analysis, to provide guidance for the further optimization of designing for 6-wing synchronous rotor.


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