scholarly journals Computer Simulation of Facial Expression. First report. Finite Deformation Analysis of Hyper-Elastic Soft-tissue by the Finite Element Method, and Identification of Mechanical Properties.

1992 ◽  
Vol 58 (551) ◽  
pp. 1107-1114 ◽  
Author(s):  
Toshio Tsuta ◽  
Chunli Wang ◽  
Kenji Yamane
2020 ◽  
Vol 86 (8) ◽  
pp. 43-48
Author(s):  
V. V. Semenov

Development of the technologies simulating optical processes in an arbitrary dispersed medium is one of the important directions in the field of optical instrumentation and can provide computer simulation of the processes instead of using expensive equipment in physical experiments. The goal of the study is simulation of scattering of optical radiation by aerosol media using the finite element method to show a practical significance of the results of virtual experiments. We used the following initial conditions of the model: radius of a spherical particle of distilled water is 1 μm, wavelength of the incident optical radiation is 0.6328 μm, air is a medium surrounding the particle. An algorithm for implementation of the model by the finite element method is proposed. A subprogram has been developed which automates a virtual experiment for a group of particles to form their random arrangement in the model and possibility of changing their geometric shape and size within predetermined intervals. Model dependences of the radiation intensity on the scattering angle for single particle and groups of particles are presented. Simulation of the light transmission through a dispersed medium provides development of a given photosensor design and determination of the minimum number of photodetectors when measuring the parameters of the medium under study via analysis of the indicatrix of scattering by a group of particles.


Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan

The concept of the finite-element procedure may be dated back to 1943 when Courant approximated the warping function linearly in each of an assemblage of triangular elements to the St. Venant torsion problem and proceeded to formulate the problem using the principle of minimum potential energy. Similar ideas were used later by several investigators to obtain the approximate solutions to certain boundary-value problems. It was Clough who first introduced the term “finite elements” in the study of plane elasticity problems. The equivalence of this method with the well-known Ritz method was established at a later date, which made it possible to extend the applications to a broad spectrum of problems for which a variational formulation is possible. Since then numerous studies have been reported on the theory and applications of the finite-element method. In this and next chapters the finite-element formulations necessary for the deformation analysis of metal-forming processes are presented. For hot forming processes, heat transfer analysis should also be carried out as well as deformation analysis. Discretization for temperature calculations and coupling of heat transfer and deformation are discussed in Chap. 12. More detailed descriptions of the method in general and the solution techniques can be found in References [3-5], in addition to the books on the finite-element method listed in Chap. 1. The path to the solution of a problem formulated in finite-element form is described in Chap. 1 (Section 1.2). Discretization of a problem consists of the following steps: (1) describing the element, (2) setting up the element equation, and (3) assembling the element equations. Numerical analysis techniques are then applied for obtaining the solution of the global equations. The basis of the element equations and the assembling into global equations is derived in Chap. 5. The solution satisfying eq. (5.20) is obtained from the admissible velocity fields that are constructed by introducing the shape function in such a way that a continuous velocity field over each element can be denned uniquely in terms of velocities of associated nodal points.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4842
Author(s):  
Huanping Yang ◽  
Wei Zhuang ◽  
Wenbin Yan ◽  
Yaomian Wang

The nanoindentation loading response of elastoplastic materials was simulated by the finite element method (FEM). The influence of the Young’s modulus E, yield stress σy, strain hardening exponent n and Poisson’s ratio ν on the loading response was investigated. Based on an equivalent model, an equation with physical meaning was proposed to quantitatively describe the influence. The calculations agree well with the FEM simulations and experimental results in literature. Comparisons with the predictions using equations in the literature also show the reliability of the proposed equation. The investigations show that the loading curvature C increases with increasing E, σy, n and ν. The increase rates of C with E, σy, n and ν are different for their different influences on the flow stress after yielding. It is also found that the influence of one of the four mechanical parameters on C can be affected by the other mechanical parameters.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4090 ◽  
Author(s):  
Leszek Czechowski ◽  
Zbigniew Kołakowski

A study of the pre- and post-buckling state of square plates built from functionally graded materials (FGMs) and pure ceramics is presented. In contrast to the theoretical approach, the structure under consideration contains a finite number of layers with a step-variable change in mechanical properties across the thickness. An influence of ceramics content on a wall and a number of finite layers of the step-variable FGM on the buckling and post-critical state was scrutinized. The problem was solved using the finite element method and the asymptotic nonlinear Koiter’s theory. The investigations were conducted for several boundary conditions and material distributions to assess the behavior of the plate and to compare critical forces and post-critical equilibrium paths.


Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 525 ◽  
Author(s):  
Nadežda Langová ◽  
Roman Réh ◽  
Rastislav Igaz ◽  
Ľuboš Krišťák ◽  
Miloš Hitka ◽  
...  

The research on population shows that the count of overweight people has been constantly growing. Therefore, designing and modifying utility items, e.g., furniture should be brought into focus. Indeed, furniture function and safety is associated with the weight of a user. Current processes and standards dealing with the design of seating furniture do not meet the requirements of overweight users. The research is aimed at designing flexible chairs consisting of lamellae using the finite element method (FEM). Three types of glued lamellae based on wood with different number of layers and thickness were made and subsequently, their mechanical properties were tested. Values for modulus of elasticity and modulus of rupture were used to determine stress and deformation applying the FEM method for modelling flexible chairs. In this research, the methodology for evaluating the ultimate state of flexible chairs used to analyse deformation and stability was defined. The analysis confirms that several designed constructions meet the requirements of actual standards (valid for the weight of a user up to 110 kg) but fail to meet the requirements for weight gain of a population.


Author(s):  
Belghoul Hakima ◽  
Madani Kouider ◽  
Merdaci Slimane ◽  
Rezgani Laid

This work consists of the study is to analysis by the finite element method the effect of the ageing of the adhesive exposed simultaneously to the temperature and water on the degradation of its mechanical properties and consequently on the transfer of loads from the plate to patch. The stress intensity factor was evaluated according to immersion time and temperature. Several parameters have been taken into consideration, namely the properties of the composite patch, temperature, water absorption, rate and length of crack, the distribution of maximum shear stresses in the adhesive and peel in the patch were also analyzed.


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