The Concept of Engineering - Assignment Example

? Finite Element Simulation 02 June Introduction The current perception of engineering is that it is a complex computation and simulation environment that breeds a heart-rending combination of actions. For example, in the works of Mori, Osakada and Takaoka (1996), it is imperative to notice that in a metal injection moulding and the simulation mechanism, a mixture of metallic powder and thermoplastics is made in addition to waxes heated and directly injected into the die cavity. Simulation of such magnitude demands a complex mix of creativity and a deeper understanding of the facets that encompass such a simulation. In the past, primitive models were used with some having to exemplify any model using hands. In as much as this is relatively good, the time spent and the accuracy of these models varied tremendously, leading to errors. However, with an increase in technological aspects of the engineering environment, it is imperative to connote the ease in simulation that is made possible by improved technology. Many simulation programs exist depending on the field of application. For example, when dealing with simulation of circuits, a program such as Circuit Maker or, in animation, Autodesk are just a few examples. In this assignment, the learner utilizes Ansys Workbench as the Computer Aided Engineering simulation program. The main reason for utilization of this software program is that it will be possible to show divergent aspects of a simulation including loading, constraints, and subjection to analysis and component performance. The beauty of this exemplification is in the fact that all the simulation is done in the context of engineering, thus it becomes possible to understand various aspects of a component. All these elements and considerations tend to rely on finite element methods. It is good to note that when dealing with finite elements, a complex problem is subdivided into smaller actual problems so that the complexity of the problem is consistently eliminated by dealing with the problem in piecemeal form. History suggests that the source of the finite simulation approach is in the fact that ancient scientists found it hard to deal with complex elasticity as well as structural analysis challenges that are inherent in the world of civil engineering and aeronautic engineering (Mori, Osakada & Takaoka 1996). To be able to solve these challenges, engineers came up with a five-step process that allows them to break the challenge into manageable pieces that are easier to deal with at every stage. The first aspect that has to be considered is the problem identification stage (Mori, Osakada & Takaoka 1996). In this first stage, the shape or structure of the object under consideration is sketched as well as the load it is anticipated to have (Mori, Osakada & Takaoka, 1996). This load and sketch is essential since it offers the engineer a better view of what needs to be provided by the end of the simulation (Mori, Osakada & Takaoka 1996). However, there are various aspects of the simulation that will emanate from the sketch, hence the need to have a clear yet close resemblance with the anticipated final project (Mori, Osakada & Takaoka 1996). {Insert Figure 1} The second aspect considered is the creation of the geometry using the software package so that a solid model is produced using a computer aided modeller (Mori, Osakada & Takaoka 1996). Although the solid is good, there are some details that may be a little hidden. In this case, a second view is needed. {Insert Figure 2} The third aspect, which is the view of the solid, is the mesh of the model created (Mori, Osakada & Takaoka 1996). A mesh offers an opportunity to clarify the divergent faces of the model under creation while the grids aid in accentuating minute details: the edges and curvatures of the model (Mori, Osakada & Takaoka 1996). {Insert Figure 3} Once the mesh has been created, the next step is clarification of the boundary conditions (Mori, Osakada & Takaoka 1996). Boundary conditions show the extent to which the model can go, depending on the specifics of the model under consideration. In this section, there are exemplification and application of loads as well as application of constraints on the model, and the output is colour coded to give a better view of the results. {Insert Figure 4} This is then followed by solving the numerical equation that leads to an evaluation of the results that are obtained (Mori, Osakada & Takaoka 1996). A fundamental aspect to be considered when dealing with finite element modelling is the fact that these models must have a definite shape (Mori, Osakada & Takaoka 1996). Dealing with an irregularly shaped model is complex and contains innumerable variables that yield complex results, thus becoming subject to errors. In the design, nodes are used to represent points joined together. In engineering, it is essential to also note that forces acting on a body do so at the nodes, thus their importance cannot be overemphasized. In finite element analysis, there are the pre-processing and post-processing parts. In the processes mentioned above, the first four steps entail the pre-processing part while the latter contains the post-processing part (Mori, Osakada & Takaoka 1996). While pre-processing is relatively simple, post-processing is complex, requiring a high accuracy level and keenness to details to avert proclivity to distortion that leads to erroneous assertions (Mori, Osakada & Takaoka 1996). In ordinary circumstances, finite element analysis of a mesh is made up of structured and unstructured aspects. The greatest disparities between the two elements are in the level of regularity or irregularity of the meshes relative to the node network in the element (Mori, Osakada & Takaoka 1996). In utilizing the computer aided design simulation program, it is imperative to predefine the expected outcome and the boundary conditions that must be adhered to. Boundary conditions are set to ensure that modeling is within a finite/ definite set of rules and concepts that lead to a specific outcome. There are five fundamental boundary condition theories that come into play at different points in the design. To start with, Neumann’s boundary condition that states that for any ordinary differential equation, say  ……………………………………………………. (i) By applying Newmann’s boundary condition with a predefined interval of [], the following results are obtained  …………………………………… (ii) so that ?and ? are definite numbers. A partial differentiation of equation (i) and applying Newmann’s boundary condition yield where all symbols have their usual meaning. Under Dirichlet’s boundary condition, similar results are obtained following partial differentiation with the only difference in representation being the replacement of  with. When dealing with one dimensional object, Robin’s boundary condition is the most applicable. Question 2: Critical Appraisal of ANSYS As a Piece of FEA From the learner’s point of view, Ansys is relatively good software to model with. The reason is in the fact that the software has a relatively user-friendly user interface, thus manipulation and modelling become relatively easy. Secondly, while searching for different components to include in the model, the software provides a wide variety of tools readily accessible to the user. Thirdly, the ease in applying and differentiating different contours within the model and colour coding makes modelling easier. The beauty of it is in the ability to view the project in more than one or two dimensional space, thus making it easier to include higher precision calibrations for nodes. Different views with a dynamic viewing platform make it fascinating to a designer since the output is rich display dynamics. The ease in zooming makes it possible to identify and correct mistakes within the model and mesh network, thus increasing the level of accuracy of the final output. However, it is also necessary to clarify that despite such admirable aspects of the program, there are some anomalies identifiable. For example, during selection and specification of the boundary conditions, it is imperative to note that this stage tends to yield errors that are redundant. To an initial user, this can be discouraging given that without proper boundary execution, the model may be subject to massive errors, thus yielding a totally different output from the initially intended one. It is also vital to note that in some machines, the program takes a lot of memory to execute, thus slowing down the machine considerably. This is not only annoying but also time wasting since the student is at the mercy of the machine’s response to commands. In some instances, the program hangs and behaves in a manner suggesting that the program has not only become unresponsive but also crushed. On restarting the computer, the program executes well, thus showing the presence of bugs in the software version in operation. References Mori, K, Osakada, K & Takaoka, S 1996, ‘Simplified three-dimensional simulation of non-isothermal filling in metal injection molding by the finite element method’, Engineering Computations, vol. 13, no. 2-4, pp. 111–121. Read More