Finite element modeling elastic properties

To measure load distribution, standard aerospace bolts were fitted with strain gauges. Both shear and axial load could be measured. A three-dimensional finite element model with linear elastic material properties was developed for calculation of load distribution prior to initiation of material failure and comparison with instm-mented bolt results. Model details are similar to those of the single-bolt model above, with a full contact analysis being performed for all bolts, washers and holes. 

Van Rietbergen, B., Weinans, H, Huiskes, R., and Odgaard, A. (1995), A new method to determine trabecular bone elastic properties and loading using micromechanical finite element models, J. Biomech. 28(1) 69-81. 

Parametric studies on two kinds of electrodes for circle-shaped diaphragms with a radius of 10 mm were conducted with the material properties and thicknesses shown in Table 9.2 [3]. The material properties E and dsj of the IPMC in Li" form were determined thorough the equivalent bimorph beam model [28]. The elastic modulus of Nafion in Li form and Poisson s ratios were obtained from literature [32, 33]. Figure 9.10 shows the shape of the two electrodes in a one-quarter finite element model of diaphragms. Figure 9.10a is the circle-shaped electrode and 9.10b is the ring-shaped electrode. 

The pushover analysis is usually performed employing the MDOF model of the structure which is similar to the linear elastic finite-element models (see Fig. la). The most important difference is that the properties of some or all of the components of the model include the postelastic strength and deformation characteristics in addition to the initial elastic properties. They are usually defined approximating the response observed in the experiments or the response defined by the theoretical analysis of individual components. The envelopes or backbone curves... 

Our ultimate goal is to develop a robust axisymmetric finite element model for accommodation and presbyopia. However, one must first determine the biomechanical characteristics of the tissues involved in accommodation, particularly of the lens. The lens itself has a complex geometry, which makes determination of the stress difficult. Hence, to determine the stress deformation characteristics of a system with simpler geometry, cylindrical disc shaped synthetic hydrogels with comparable elastic properties were investigated. 

A computational design procedure of a thermoelectric power device using Functionally Graded Materials (FGM) is presented. A model of thermoelectric materials is presented for transport properties of heavily doped semiconductors, electron and phonon transport coefficients are calculated using band theory. And, a procedure of an elastic thermal stress analysis is presented on a functionally graded thermoelectric device by two-dimensional finite element technique. First, temperature distributions are calculated by two-dimensional non-linear finite element method based on expressions of thermoelectric phenomenon. Next, using temperature distributions, thermal stress distributions are computed by two-dimensional elastic finite element analysis. 

Theret et al. [1988] analyzed the micropipette experiment with endothelial cell. The cell was interpreted as a linear elastic isotropic half-space, and the pipette was considered as an axisymmetric rigid ptmch. This approach was later extended to a viscoelastic material of the cell and to the model of the cell as a deformable layer. The solutions were obtained both analytically by using the Laplace transform and numerically by using the finite element method. Spector et al. [ 1998] analyzed the application of the micropipette to a cylindrical cochlear outer hair cell. The cell composite membrane (wall) was treated as an orthotropic elastic shell, and the corresponding problem was solved in terms of Fourier series. Recently, Hochmuth [2000] reviewed the micropipette technique applied to the analysis of the cellular properties. 

A thorough understanding of the mechanics of UHMWPE is important for efforts to improve the performance of orthopedic components. Elastic properties, resistance to plastic deformation, stress and strain at failure, fatigue behavior, and wear resistance of UHMWPE are believed to play roles in the life expectancy of an UHMWPE bearing. There exists a fundamental relationship between a material s intrinsic mechanical properties, akin to state variables, and how a structure made of the material will respond under mechanical stimuli. This material-specific fundamental relationship is referred to as a constitutive model. A validated constitutive model is a required input to a finite element (FE)-based simulahon of a structure made of the material in question. 

The use of theoretical models to predict the properties of CNT composites has been useful in dealing with certain aspects of these nanocomposites. In particular, Brinson et al. [41,106] addressed the issue of CNT waviness or curvature and its effects on composite properties. TEM observations of embedded CNTs have shown that they are not rectilinear but have some degree of waviness [99], which may be due to their crystalline defects and elastic flexibility. A reduction in the modulus of wavy CNTs can be expected due to CNT anisotropy. Finite element analysis was used to calculate what the effective reinforcing modulus would be... 

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