Finite-element analysis model detail

Advancements in the modelling of the consequences of train collisions using detailed finite element analysis models. 

In less frequent situations a more comprehensive analysis approach is used to analyze the structure as a whole. For example, a finite element analysis of an entire building may be performed. Obviously, the load path need not be predetermined when such global analysis methods are used. However, the load path is influenced by the type and level of detail of the modeling so that engineering judgment and experience are also necessary to achieve a safe and economical design,... 

For the coarse estimation of extruder size and screw speed, simple mass and energy balances based on a fixed output rate can be used. For the more detailed design of a twin-screw extruder configuration it is necessary to combine implicit experience knowledge with simulation techniques. Theses simulation techniques cover a broad range from specialized programs based on very simple models up to detailed Computational Fluid Dynamics (CFD) driven by Finite Element Analysis (FEA) or Boundary Element Method (BEM). 

The models used for Eq. 4.3 may range from simple to complicated. Most of these functions are already known from system design and from the detailed design of the sensing element (see Section 4.1.3). If there are no analytical models available or if the physical relationships are too complicated for analytical description, finite element analysis, network-type analysis, or empirical studies need to be used to obtain the relationships summarized in Eq. 4.3. 

In a design one has to identify the mode(s) to suppress. It usually requires a special type of finite element analysis (FEA), called modal analysis. At CSA detailed FE models use MSC.Nastran (MSC.Software, Santa Ana, CA., USA), running on dual processor HP/Linux machines. Dynamic models typically require less detail than static stress models in order to accurately capture the modal shapes. FE results show the vibrations as strain energy identifying regions of high strain energy shows where vibration suppression methods should be applied. 

Leaks, back pressure, and actuator dynamics all influence the performance of peristaltic pumps. Leaks and back pressure effects will alter the distribution of fluid as actuators open and close. The dynamics of the actuators determines the maximum actuatitm rate, which in turn limits the maximum flow rate. These effects can be incorporated into lumped-parameter models for analysis and simulation. We do not pursue this further in this entry, but refer the reader to the literamre. One general approach is presented in Ref. [7]. Also relevant for further smdy are Refs. [6, 8], and [13], which present dynamic models for pneumatic and electrostatic pumps, respectively. All of these works are applied to liquid pumps. For gas pumps, or robustness to bubbles, compressibility becomes a factor. Some considerations of micropumps for compressible fluids may be found in Ref. [1]. Finite-element analysis of individual chambers can also be used to obtain detailed predictions of pump dynamic performance. 

The main characteristics of the materials, design and production of the combat helmet have been explored in detail. Finite element analysis and simulation tools have been revealed to be very useftil in ballistic-related research, as long as the researcher understands the complexity of the material model and high-velocity impact penetrators, and computational model experiments have been shown to be... 

The subject of filler reinforcement of rubbers has been an area of interest to the rubber industry for more than a century. Various models had been proposed in the past to explain the filler reinforcement in vulcanized rubber. The use of modern finite element analysis (FEA) and various mathematical models have made further progress to understand the mechanisms of reinforcement in filled vulcanized rubber. But this does not imply that a complete understanding of the subject has been achieved. The detailed effects of filler properties such as surface area and shape on the filler reinforcement are still not completely understood. A detailed understanding of the filler reinforcement should provide an insight into the increase in modulus and strength. 

Generally, the finite element analysis is done in conjunction with the geometric modeling of the part on a computer. This is discussed in detail in Chapter 10 where examples are given of the use of the method in conjunction with computer modeling of the parts for design. 

The chapter includes brief descriptions of the analysis modules, ZEUS-NL and Vec-Tor2, as well as the simulation coordinator program UI-SIMCOR (Kwon et ah, 2005), that was used to combine these analysis tools. The modeling details for the 54-story dnal-system high-rise structure used as the reference implementation are presented including the techniques used to model the interface between the two structural models. The influence of different interface assumptions on predicted response is also examined. Using the selected interface boundary conditions, comprehensive comparisons between and discussions of the predicted static and dynamic responses by the MDFEA and by a conventional finite element analysis are presented. 

For further information on ceramic actuators, see Uchino (1993). It has been recognized that in modern multilayer piezoelectric actuators (MPAs), the combination of thermal, electrical and mechanical loads during service may affect the functional integrity of the devices. As the details of these effects and their synergistic coupling are still unknown, modeling of the nonlinear behavior of these temperature-sensitive functional properties and their implementation into finite element analysis (FEA) tools has been performed recently (Griinbichler et al., 2008). 

The experimental tests have been carried out on two pressure vessel models, namely that of Dungeness B and Oldbury, both cylindrical with top and bottom flat caps, with different prestressing systems, indicate different modes of failure. These will be the reference models of the limit state analysis which has been developed in the text and which will be finally provided by using 3D hybrid finite element analysis under increasing gas load pressure. The Oldbury will be given a detailed assessment later on in the text. 

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