Publikationen ohne Studienabschluss

Product development is characterised by numerous synthesis and analysis loops. Analysis provides information on the fulfillment of the required properties of the system under development. Analysis results therefore are an important basis for further synthesis steps. In the context of Model-Based Systems Engineering (MBSE), different types of simulation models play an important role. The overall system (product) can be broken down to system elements. For each system element a set of models has to be established, that provides the required degrees of fidelity, representations of system properties, flows, etc. reflecting the variety of modelling purposes. These models have to be integrated horizontally (same system level along the relevant flows of material, energy, and information) and vertically (aggregation from subsystem level to the overall system level, refinement in the opposite direction) to create a holistic model-based system representation. An important and challenging task is to identify and shape relevant subsystem models. In order to define an appropriate structure of these models, model developers may utilize criteria like selected properties of system elements and interrelations, their degree of detail or modelling assumptions. The relevant criteria have to be made transparent. For this purpose, the paper discusses the concept of model signatures that contain relevant meta information about each single model of all system elements, subsystems up to models of the overall system. This standardized meta information enables an identification and selection of those models and the decision on the necessary model integration. The concept is discussed on the basis of a roller bearing as an example out of an electro-mechanical drivetrain. A potential analysis provides information about the possible usage of the model signatures concept.

Compliant mechanisms are widely applied in precision engineering, measurement technology and microtechnology, due to their potential for the reduction of mass and assembly effort through the integration of functions into fewer parts and an increasing motion repeatability through less backlash and wear, if designed appropriately. However, a challenge during the design process is the handling of the multitude of geometric parameters and the complex relations between loads, deformations and strains. Furthermore, some tasks such as the dimensioning by means of optimization or the modeling for a controller design require a high number of analysis calculations. From this arises the need for sufficient computational analysis models with low calculation time. Existing studies of analysis models are mostly based on selected load cases, which may limits their general validity. The scope of this article is the comparison of models for the analysis of corner-filleted flexure hinges under various loads, to determine their advantages, disadvantages and application fields. The underlying methods of the study can further be used to evaluate future models based on a broad selection of possible load cases.

MBSE and SysML are increasingly finding their applications in industry as well as in academia. The reuse of the information described in SysML models depends, among others, on the modelling methods, management of dependencies between elements and on the needed remodelling effort. In this paper, a modelling method is presented that address the reuse of SysML models and descriptions as well as reuse of model variants in SysML. A case example is presented to explain the modelling methods and the gained experience is summarised in the form of general recommendations for further use.

Since the 1950ies Design Theory and Methodology has described product and system development as a process that goes through the stages of requirements definition, considerations of functions, allocation of solution principles and, finally, detailing. Computer support of this process has more or less evolved backwards: Starting with manufacturing information (i.e. supporting processes after product development), going through geometric modelling to simulation - which is basically our present state. Functional modelling and requirements management has been very difficult to realise with conventional methods. Today, Model-Based Systems Engineering (MBSE) offers new ways to come to a holistic coverage of the product development process providing and - very importantly - linking model elements for all of its stages. Starting from the needs, as seen from Design Theory and Methodology, this article describes the current state of MBSE as a new, integrative approach for product and system development and identifies needs for further progress in this field.