The Flex Representation Method (FRM) leverages unique computational advantages of splines to address limitations in the process of building CAE simulation models from CAD geometric models. Central to the approach is the envelope CAD domain that encapsulates a CAD model. An envelope CAD domain can be of arbitrary topological and geometric complexity. Envelope domains are constructed from spline representations, like U-splines, that are analysis-suitable. The envelope CAD domain can be used to approximate none, some, or all of the features in a CAD model. This yields additional simulation modeling options that simplify the model-building process while leveraging the properties of splines to control the accuracy and robustness of computed solutions. Modern integration techniques are adapted to envelope domains to maintain accurate solutions regardless of the CAD envelope chosen. The potential of the method is illustrated through several carefully selected benchmark problems.

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Conveyor chains are often subject to repetitive shock loads during normal operations. This can cause accelerated wear in the chain leading to premature chain replacementor chain failure (Otoshi, 1997, p. 4). In this thesis a new approach for reducingshock load related wear in conveyor chains is proposed. The scope and objective ofthis project is to investigate the shock load phenomenon and develop a dynamic pinlink chain plate. A study into chain wear and shock loads of chain driven conveyorswas made to identify problem areas. Additionally, a Simulink model was created tosimulate the influence of shock loads on conveyor chains. Common wear as a result ofshock loads are identified as pin failure, bushing failure, scuffing, chain plate failure,fatigue and chain elongation, (Otoshi, 1997, p. 76-78). Nine concepts were drafted and evaluated using methods described in (Ulrich &Eppinger, 2016). The concepts were simulated using Finite Element Analysis (FEA)and two concept iterations, Concept B v.3 and Concept C v.3, were manufacturedfor static tensile tests using two different setups and Digital Image Correlation (DIC)system for additional strain measuring. The breaking load for Concept B v.3 andConcept C v.3 is 105 and 70 kN respectively. The approximate yield strength ofConcept B v.3 is 11 kN and 40 kN for Concept C v.3. The Fatigue limit was estimatedto 10 kN for Concept B v.3 and 20 kN for Concept C v.3. A nonlinear FEA for Concept C v.3 and Concept B v.3 provided additional insightinto the behaviour of the pin link chain plates during high stress concentrations. While neither the linear static nor nonlinear static analyses managed to accuratelypredict the behaviour of Concept B v.3, the simulated results of Concept C v.3 werein line with the observed tensile tests. From the results it is concluded that a dynamic chain plate in the form of ConceptC v.3 has the potential to reduce the magnitude of the force in the chain imposedby shock loads, while still following the current ISO standard for conveyor chains. The resulting design proposition provides an easy to manufacture high strength chainplate with increased elastic properties.Future work should be focused on determining the fatigue life and shock load resistanceof the developed chain plate. It is recommended that material selection is focused onwear and fatigue resistant materials and that both simulated and physical dynamictesting is performed.

Finite element(FE) method has been used to model cutting process since 1970s. However, it requires special techniques to cope with the difficulties in simulating extremely large strain when compare to static or small deformation problems. With the advancement of FE techniques, researchers can now have a deeper insight of the mechanism of material flow and chip formation of metal cutting process. Even the stagnation effect of the workpiece material in front of the cutting edge radius can be captured by using FE techniques such as Remeshing and Arbitrary Lagrangian Eulerian(ALE) formulation. However most of this models are limited to plane strain assumption which means they are 2-dimensional. Although 3D models are existing in the literatures, most of them employ Remeshing technique which is very computationally intensive and has many critics regarding its accuracy due to its frequent remeshing and mapping process. The rest of the 3D models employ Lagrangian formulation. The 3D models by Lagrangian formulation have the same limitations and drawbacks as in 2D models, as it requires failure criteria and in most of the cases predefined partition surfaces are also required. ALE technique on the other hand resolves all the drawbacks of the other formulations, it not only inherits the advantages of the other techniques but also has its own unique advantages such as it can simulate a longer time span up to couple seconds more economically by fixing the number of elements used. Although it's commonly accepted that ALE formulation is superior to other formulations of techniques in modeling metal cutting process, its usage is only limited to 2D models. Limited 3D ALE metal cutting models is available in the literature. Thus the main objective of this research is to explore the possibility of building a 3D metal cutting model with ALE formulation. The reliability and limitations will also be studied. Furthermore, Couple Eulerian-Lagrangian(CEL) formulation is a recent developed formulation that has a lot of potential in modeling metal cutting process in 3D. It will be compared with ALE models to study its potential and limitations in modeling metal cutting process. A new frictional model will also be proposed, which suggests that the frictional phenomenon in metal cutting is a consolidated effect of both friction between material interface and shear yield of the workpiece material. This idea provide a brand new perspective of viewing the friction phenomenon of metal cutting compared to those existed models. / Thesis / Master of Science (MSc)

Heat flux and heat conductance at the metal mold interface plays a key role in controlling the final metal casting strength. It is difficult to obtain these parameters through direct measurement because of the required placement of sensors, however they can be obtained through inverse heat conduction calculations. Existing inverse heat conduction methods are analyzed and classified into three categories, i.e., direct inverse methods, observer-based methods and optimization methods. The solution of the direct inverse methods is based on the linear relationship between heat flux and temperature (either in the time domain or in the frequency domain) and is calculated in batch mode. The observer-based method consists on the application of observer theory to the inverse heat conduction problem. The prominent characteristic in this category is online estimation, but the methods in this category show weak robustness. Transforming estimation problems into optimization problems forms the methods in the third category. The methods in third category show very good robustness property and can be easily extended to multidimensional and nonlinear problems. The unknown parameters in some inverse heat conduction methods can be obtained by a proposed calibration procedure. A two-index property evaluation (accuracy and robustness) is also proposed to evaluate inverse heat conduction methods and thus determine which method is suitable for a given situation. The thermocouple dynamics effect on inverse calculation is also analyzed. If the thermocouple dynamics is omitted in the inverse calculation, the time constant of thermocouple should be as small as possible. Finally, a simple model is provided simulating the temperature measurement using a thermocouple. FEA (Finite Element Analysis) is employed to simulate temperature measurement.

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