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Publications 2005 - Abstracts  Topologieoptimierung auf statische und dynamischen Eigenschaften zur Verbesserung des Strukturverhaltens - Darstellung der Methodik und die Auswirkungen bei der Konstruktion von Werkzeugmaschinen Keywords Strukturoptimierung: Die Wahl der richtigen Methode für Simulation und Optimierung bei industriellen Fragestellungen Der vorliegende Bericht bietet einen Überblick über gängige Strukturoptimierungsarten, wie sie für industrielle Anwendungen aus Automobilbau und Luft- und Raumfahrttechnik Keywords Parameter Optimization, FEM, Non Parametric Optimization, Design of Experience, Responce Surface Methode, Multi disciplinary Optimization (MDO), Robust Design, Laminates Composites Nonparametric gradient-less shape optimization for real-world applications (pdf) A nonparametric gradient-less shape optimization approach for finite element stress minimization problems is presented. The shape optimization algorithm is based on optimality criteria, which leads to a robust and fast convergence independent of the number of design variables. Sensitivity information of the objective function and constraints are not required, which results in superior performance and offers the possibility to solve the structural analysis task using fast and reliable industry standard finite element solvers such as ABAQUS, ANSYS, I-DEAS, MARC, NASTRAN or PERMAS. The approach has been successfully extended to complex nonlinear problems including material, boundary and geometric nonlinear behavior. The nonparametric geometry representation creates a complete design space for the optimization problem, which includes all possible solutions for the finite element discretization. The approach is available within the optimization system TOSCA and has been used successfully for real-world optimization problems in industry for several years. The approach is compared to other approaches and the benefits and restrictions are highlighted. Several academic and real-world examples are presented. Keywords Optimization of the Seam Weld Position considering the Fatigue Life Concerning fatigue life, welds are often known to be the most critical component in welded constructions. Position and form of the weld are thereby the determining factors. In the present report, the determination of these parameters by applying the optimization software OPTIMUS is shown using the example of a front axle carrier. The aim of the optimization is to minimize the damage within the weld. For this purpose several FE-models of different weld geometries are generated with the help of a Morpher and their subsequent fatigue lives are evaluated. A model based on these results is used for the calculation of the optimum parameters. The results show a good correspondence with the production model and confirm the high potential of this method. Keywords Fatigue, Welding, Optimization, Simulation, OPTIMUS Probabilistic Design Approach for Package Design and Solder Joint Reliability Optimization for a Lead Free BGA Package The natural variations that exist in the material properties and manufacturing processes in the assembly of an IC device can impact the solder joint reliability. It would be desirable and more efficient if these variations were incorporated into the design so that when all variations are taken into account, the assembled device always operates away from the failure domain. It is well known that a deterministic optimum is not always a reliable solution as scatter on the inputs may propagate into scatter on the outputs and even small parameter changes may have substantial effects on the functional performance. The deterministic optimum has to be shifted to a reliable optimum. By taking into account realistic variability, it is ensured that constraints on performance targets are never violated. This requires an incorporation of a probabilistic design methodology in the FE simulations. Keywords Robust Design, OPTIMUS Multidisciplinary Optimization considering Crash and NVH Loadcases The development of a car body is a very complex process, as various functional requirements have to be considered. Different targets with sometimes competitive issues define a challenge for the development engineers. Today, numerical simulation is a well established and widespread tool to predict, analyse and optimize the functional characteristics of a car. The engineer describes a design and the simulation will predict the performance of this design. Very often, numerical optimization is performed considering only one single simulation discipline. Once an optimal design has been found it has to be verified for all other relevant disciplines. In most cases this process leads to significant design changes. Therefore, it requires a great effort of all participating engineers to find an optimum design that satisfies all relevant disciplines. This process is very time consuming and often ends up in an unsatisfying design compromise. Keywords Process Optimization, Multi Disciplinary Optimization, Automotive Faster to Superior Casting Components by Employment of the Topology Optimization with the Supplier Heidenreich & Harbeck AG supplies leading machine manufacturers with ready-to-mount machined castings and engineering services. Due to the global competition and constantly shortening development-cycles the company is pressed for time with the development and manufacturing of poured prototypes. Keywords Machine Components, Topology Optimization, Acceleration of Development Time The Use of OPTIMUS for Advanced Multi-Disciplinary Structural Optimization in Automotive Applications The design and analysis of automotive structures involves meeting several competing objectives for multiple attributes such as Noise and Vibration (NVH), Durability, Occupant Safety and Vehicle Dynamics. To achieve an optimal design several dedicated CAE analysis tools are used to evaluate the functional performance at the component or system level for each of the different attributes. Keywords: Optimization, Design of Experiments, Multi-Disciplinary, Optimal Design Warpage Minimization of the HVQFN Map Mould with OPTIMUS A viscoelastic model for the compound is required, since time and temperature history play a major role. In the production process the HVQFN 100 is forced to remain flat during PMC by applying of a dead weight. The good agreement between warpage measurments and FEM warpage results shows that fully cured viscoelastic compound properties can be used. Also adding curing shrinkage had only little effect on the end warpage. Keywords Casting simulation, OPTIMUS The Effect of Spot Weld Failure on Dynamic Vehicle Performance Spot welds are the dominant joining method in the automotive assembly process. As the automated assembly process is not perfect, some spot welds may be absent when the vehicle leaves the assembly line. Furthermore, spot welds are highly susceptible to fatigue, so that a substantial number may fail during the vehicle lifetime. The scope of this paper is twofold. First, the impact of spot weld quality and design on a vehicle.s functional performance is reviewed, addressing strength and stiffness, NVH and durability. The overview briefly covers both experimental tests and predictive Finite Element (FE) modeling approaches, explains the complexity of a spot weld design problem and discusses optimization strategies. Second, an industrial robustness study is presented that assesses the effect of spot weld failure on dynamic vehicle characteristics. Damaged models are generated automatically, by breaking a subset of the vehicle’s spot welds, using a (weighted)-uniform selection probability. Monte Carlo simulations are then used to assess the scatter on dynamic vehicle characteristics. Keywords Spot Weld, Optimization, Automotive Industry, Robust Design Design Improvements of Composite Aerospace Structures using Reliability Analysis The need of improvements in engineering designs especially with composite materials is nowadays a major request of the aerospace industry. Deterministic approaches are unable to take into account all the variabilities that characterize composites properties without oversizing structures. The necessity of assessing the probability of failure of a particular design requires a new methodology based on reliability analysis and design optimization through probabilistic models of physical properties. This paper intends to give a brief description of the most used methods for reliability analysis and point out the advantages of the application of these methods to shift from a deterministic to a probabilistic approach. Thus a methodology will be outlined that could serve as a guideline to develop a more efficient and optimized design process with particular focus on computational issues that could arise through the application of reliability analysis. Some application examples will be given to better explain the new methodology and the necessary theoretical background needed to understand the results; particular interest will be given to design optimization and its advantages in engineering designs. Keywords Composite Materials, Optimization, Reliabity Analysis, Aerospace Last update: 2009-09-03
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