Finite element stress analyses

Lally C, Dolan p Prendergast PJ. Cardiovascular stent design and vessel stresses a finite element analysis. J Biomech 2005 38 1574-1581. 

The indirect analytical nondestructive evaluation methods of interest are thermal analysis, finite element stress analysis, strain gauging, photoelasticity and brittle coatings. 

Other methods available for nondestructive evaluations are indirect in nature, but may be useful in certain situations. These methods will only be discussed in a cursory fashion and more detailed aspects can be obtained from the literature. It is useful to note that stress in any structure plays a vital role, and that the methods involved in determining stress in an engineering component or structure in the process conditions is of vital importance. The methods used in determining stress are finite element stress analysis, strain gaging, the photoelastic method and brittle coatings. 

The second important assumption in the analysis is that interfacial failure occurs only in shear, i.e. that any peeling stress, normal to the interface, is negligible. Analysis of an elastic bilayer (5) shows that, for the experimental parameters employed here, the peeling stress is, in fact, an order of magnitude less than the shear stress. Furthermore, finite element analysis (6) shows that the normal stress is compressive rather than tensile for the thicknesses of PET and Ni used here. Finally, it will be shown that the experimental results are consistent with the one-dimensional analysis presented above. 

Experimental and numerical analysis methods have both been used to analyze the effects of post-core system. Since experimental methods may be too time consuming, expensive and require sophisticated procedure with coarse results, numerical analysis provides an effective tool. For numerical analysis, finite element method (FEM) was normally employed. Several studies investigated stress distribution in... 

The AUGUR information on defect configuration is used to develop the three-dimensional solid model of damaged pipeline weldment by the use of geometry editor. The editor options provide by easy way creation and changing of the solid model. This model is used for fracture analysis by finite element method with appropriate cross-section stress distribution and external loads. 

The S -shaped flexible elements were required to keep the stiffness and stresses low, due to the relatively heavy rotor weight as evident by the finite element stress analysis shown in Figure 6-30. The wire EDM teehnology allows the produetion of sueh a damper deviee, whieh ean be easily designed with an offset to eompensate for the defleetion due to rotor weight. 

The failure determining stresses are also often loeated in loeal regions of the eomponent and are not easily represented by standard stress analysis methods (Sehatz et al., 1974). Loads in two or more axes generally provide the greatest stresses, and should be resolved into prineipal stresses (Ireson et al., 1996). In statie failure theory, the error ean be represented by a eoeffieient of variation, and has been proposed as C =0.02. This margin of error inereases with dynamie models and for statie finite element analysis, the eoeffieient of variation is eited as Q = 0.05 (Smith, 1995 Ullman, 1992). 

Strain gages may be applied to the test unit at all points where high stresses are anticipated, provided that the configuration of the units permits such techniques. The use of finite element analysis, models, brittle lacquer, etc., is recommended to confirm the proper location of strain gages. Three-element strain gages are recommended in critical areas to permit determination of the shear stresses and to eliminate the need for exact orientation of the gages. 

Failure analysis using modern techniques such as finite element stress analysis and fracture mechanics Metallurgical and weld analysis Chemical engineering and process capability Quality assurance... 

With computers the finite element analysis (FEA) method has greatly enhanced the capability of the structural analyst to calculate displacement, strain, and stress values in complicated plastic structures subjected to arbitrary loading conditions. Details on FEA are reviewed in Chapter 2, Finite Element Analysis. 

Although many interface models have been given so far, they are too qualitative and we can hardly connect them to the mechanics and mechanism of carbon black reinforcement of rubbers. On the other hand, many kinds of theories have also been proposed to explain the phenomena, but most of them deal only with a part of the phenomena and they could not totally answer the above four questions. The author has proposed a new interface model and theory to understand the mechanics and mechanism of carbon black reinforcement of rubbers based on the finite element method (FEM) stress analysis of the filled system, in journals and a book. In the new model and theory, the importance of carbon gel (bound rubber) in carbon black reinforcement of rubbers is emphasized repeatedly. Actually, it is not too much to say that the existence of bound rubber and its changeable and deformable characters depending on the magnitude of extension are the essence of carbon black reinforcement of rubbers. 

We could attempt to calculate the loss in stress associated with each of these temperature drops by calculations using either a mathematical model or finite element analysis. We would need the following information as input ... 

Finite element formulations for linear stress analysis problems are often derived by direct reasoning approaches. Fluid flow and other materials processing problems, however, are often viewed more easily in terms of their governing differential equations, and this is the... 

Goel VK et al (1995) Interlaminar shear stresses and laminae separation in a disc finite element analysis of the L3-L4 motion segment subjected to axial compressive loads. Spine (Phila Pa 1976) 20(6) 689-698... 

Finite element methods (FEM) are capable of incorporating complex variations in materia stresses in the time varying response. While these methods are widely available, they are quite complex and, in many cases, their use is not warranted due to uncertainties in blast load prediction. The dynamic material properties presented in this section can be used in FEM calculations however, the simplified response limits in the next section may not be suitable. Most FEM codes contain complex failure models which are better indicators of acceptable response. See Chapter 6, Dynamic Analysis Methods, for additional information. 

Fan, C.F. and Hsu, S.L. (1992a) A study of stress distribution in model composites by using finite-element analysis. I. End effects. J. Polym. Sci. Part B. Polym. Phy. 30, 603-618. 

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