Uwe Schramm

Recent Developments in the Commercial Implementation of Topology Optimization

Topology optimization has matured to be a practical design tool. After several years of success in the automotive industry, topology optimization has been introduced in other industries with great success. Design processes in the consumer products and aerospace industry benefit greatly from the use of topology optimization. The introduction of manufacturing constraints made the technology even more appealing. The paper will discuss recent developments in the implementation of topology optimization in commercial software and the use in a digital engineering environment.

BEAM STIFFNESS MATRIX BASED ON THE ELASTICITY EQUATIONS

A new general beam stiffness matrix which accounts for bending, torsion and shear deformation is derived from an elasticity solution of the beam. The influence of shear and torsion is considered using a 3×3 matrix of deformation coefficients. Numerical examples are presented to demonstrate the behaviour of the deformation coefficients and of the beam stiffness matrix.

Crashworthiness design using structural optimization

Consideration of the crashworthiness of a design requires nonlinear structural analysis. Analysis codes for such problems are based on explicit integration schemes. Parameter changes are derived from the results of the analysis to improve the design in order to meet the requirements of regulations and design goals. Today, the usual approach is a trial-and-error search that is very expensive with respect to labor costs. Optimization methods can be used to automate the search for the optimum design. Closed loop software for the optimization of structures with nonlinear behavior such as known for linear statics is not available currently. Usually addons to the non-linear codes based on response surface methods or finite difference sensitivity analysis are used. The paper discusses the incorporation of optimization into the crashworthiness design of automotive structures. A very efficient response surface method is presented. Some examples show practical applications of structural optimization in the development of motor vehicles. The use of structural optimization reduces the manual effort to search for an optimal design considerably.

Sequential Optimization and Reliability Assessment Method for Metal Forming Processes

Uncertainty is inevitable in any design process. The uncertainty could be due to the variations in geometry of the part, material properties or due to the lack of knowledge about the phenomena being modeled itself. Deterministic design optimization does not take uncertainty into account and worst case scenario assumptions lead to vastly over conservative design. Probabilistic design, such as reliability-b ased design and robust design, offers tools for making robust and reliable decisions under the presence of uncertainty in the design process. Probabilistic design optimization often involves double-loop procedure for optimization and iterative probabilistic assessment. This results in high computational demand. The high computational demand can be reduced by replacing computationally intensive simulation models with less costly surrogate models and by employing Sequential Optimization and reliability assessment (SORA) method. The SORA method uses a single-loop strategy with a series of cycles of deterministic optimization and reliability assessment. The deterministic optimization and reliability assessment is decoupled in each cycle. This leads to quick improvement of design from one cycle to other and increase in computational efficiency. This paper demonstrates the effectiveness of Sequential Optimization and Reliability Assessment (SORA) method when applied to designing a sheet metal flanging process. Surrogate models are used as less costly approximations to the computationally expensive Finite Element simulations.

Optimization technology in design: trends, direction, and gaps

Optimization technology changes the design process into a process driven directly by computational analysis. Different techniques are discussed and classified with respect to their applicability in design. Gaps in transferring technology to practical application as well as missing solutions are identified.

Strukturoptimierung — Ein effektives Werkzeug in der Automobilentwicklung

Ziel des konstruktiven Entwicklungsprozesses ist der Entwurf von kostengunstigen Konstruktionen, die bestimmte Anforderungen an Funktionalitat und Gestaltung erfullen. Konstruktionen sind das Ergebnis eines iterativen Vorganges, wobei Entwurfsanderungen aus numerischen Analysen des Strukturverhaltens abgeleitet werden. Ublicherweise fuhren Erfahrungswerte zu solchen Anderungen. Mit Hilfe von Optimierungsverfahren konnen Entwurfsanderungen direkt aus den Analyseergebnissen numerisch abgeleitet werden. Das Entwurfsproblem kann als Strukturoptimierungsproblem formuliert werden. Die Anwendung von Optimierungsverfahren fuhrt zu einer effektiven Suche nach der fur eine bestimmte Anwendung gunstigsten Parameterkombination. Dieser Aufsatz stellt praktische Anwendungen von Strukturoptimierungsverfahren aus der Erfahrung des CAE-Dienstleisters und Softwareherstellers Altair Engineering vor.

Automatic Integration of Topology and Shape Optimization

In this paper, an approach for the automatic integration of topology and shape optimization is proposed with the goals of increasing the degree of automation and therefore increasing the efficiency in engineering development cycles. A numerical example of engine bracket is illustrated as a typical application. Address the integration of topology and shape optimization to provide a full picture about the geometric representation of mechanical products.