Architecture for the Integration of High Performance Computing Applications in PLM

High Performance Computing (HPC) has become ubiquitous for simulations in the industrial context. To identify the requirements for integration of HPC-relevant data and processes a survey has been conducted concerning the German car manufacturers and service and component suppliers. This contribution presents the results of the evaluation and suggests an architecture concept to integrate data and workflows related with CAE and HPC-facilities in PLM. It describes the state of the art of HPC-applications within the simulation domain. Intensive efforts are currently invested on CAE-data management. However, an approach to systematic data management of HPC does not exist. This study states importance of an integrating approach for data management of HPC-applications and develops an architectural framework to implement HPC-data management into the existing PLM landscape. Requirements on key functionalities and interfaces are defined as well as a framework for a reference information model is conceptualized.

The Effect of Form on Attributing Meanings to Materials

Materials in product design used to be selected based especially on manufacturability concerns and technical aspects such as strength, conductivity, elasticity, etc. Nowadays, the increasing recognition for more intangible issues like meaning attribution or creating emotions in product design made designers shift their focus towards the intangible aspects in their materials selection activity as well. In this research, we aim to concentrate particularly on attributing meanings to materials. It is crucial to realize that several aspects (function, use, context, user, etc.) can be effective in attributing meanings to materials and they should be taken into consideration during the selection process. In this paper, we focus intensively on one of these aspects: the effect of form on attributing meanings to materials. The paper consists of four related studies exploring how people associate some forms with some particular materials and weather form can be effective in changing these ascribed meanings, or not.

A New Approach to Interactive Grasping Simulation of Product Concepts in a Virtual Reality Environment

Customer evaluation of concepts plays an important role in the design of handheld devices, such as bottles of douche gels and shampoos, where the phenomenon of grasping needs to be evaluated. In these applications important information on the aspects of ergonomics and user behaviors could be gathered from computer simulation. It is our ultimate goal to develop an environment in which users and designers can freely interact with product concepts. In our approach to grasping simulation there is no tactile feedback and we do not measure the exerted grasping forces. There is no wiring of the human hand, and the users are not limited in their movements. We measure the motion of the human hand, compute the grasping forces based on anthropometric data, and simulate the reaction of product concepts in a physically based virtual reality environment. Our contribution consists of: (i) a method, which takes into account the anatomy of the human hand in order to determine the maximum grasping forces, and (ii) an approach which enables to control the grasping forces based on (a) the penetration of the virtual human hand into the virtual model of product concept (b) the posture of the grasping, and (c) the angles of the joints. The paper reports on the framework of our approach and presents an application.

Combining Geometric Constraints With Physics Modeling for Virtual Assembly Using SHARP

This research combines physics-based and constraint-based approaches for virtual assembly simulations where geometric constraints are created or deleted within the virtual environment at runtime. In addition, this research provides a solution to low clearance assembly by utilizing B-Rep data representation of complex CAD models for accurate collision/physics results. These techniques are demonstrated in the SHARP software (System for Haptic Assembly and Realistic Prototyping). Combining physics-based and constraint-based techniques and operating on accurate B-rep data, SHARP can now assemble parts with 0.001% clearance and can accurately detect collision responses with 0.0001mm accuracy. Case studies are presented which can be used to identify the suitable combination of methods capable of best simulating intricate interactions and environment behavior during manual assembly.

Evaluating Supplier Involvement Using DEA and Piecewise Triangular Fuzzy AHP

Data Envelopment Analysis (DEA) has been widely applied in evaluating multi-criteria decision making problems which have multi-inputs and multi-outputs. However, the traditional DEA method does neither take the decision maker’s subjective preferences to the individual criteria into consideration, nor rank the selected options or decision making units (DMUs). On the other hand, Satty’s Analytical Hierarchy Process (AHP) was established to rank options or DMUs under multi-inputs and multi-outputs through pairwise comparisons. But in most cases, the AHP pairwise comparison method is not perfectly consistent, which may give rise to confusions in determining the appropriate priorities of each criterion to be considered. The inconsistency implicates the fuzziness in generating the relative important weight for each criterion. In this paper, a novel method which employs both DEA and AHP methods is proposed to evaluate the overall performance of suppliers’ involvement in the production of a manufacturing company. This method has been developed through modifying the DEA method into a weighting constrained DEA method by using a piecewise triangular weighting fuzzy set which is generated from the inconsistent AHP comparisons. A bias tolerance ratio (BTR) is introduced to represent the varying but restrained weighting values of each criterion. Accordingly, the BTR provides the decision maker a controllable parameter by tightening or loosening the range of the weighting values in evaluating the overall performance of available suppliers, which in hence, overcomes the two weaknesses of the traditional DEA method.

A Multi-Level Freeform Surface Feature Model

Feature modelling is a valuable technology to define and manipulate product models through advanced operations. Parameters and constraints can be included in feature models to represent particular design intent. In this way, entire families of shapes, not just specific instances, can be modelled. Freeform surface feature modelling, which extends the concept of feature modelling to freeform shapes, still suffers from a number of shortcomings as regards parametric modelling. In particular, it lacks good facilities to add new parameters to a model. We present a multi-level freeform surface feature model that can be used to implement such facilities. The model contains an unevaluated, a partially evaluated and an evaluated level. The paper describes the three levels and how these are generated.

Decision Retrieval and Storage Enabled Through Description Logic

The problem addressed in the paper is how to represent the knowledge associated with design decision models to enable storage, retrieval, and reuse. The paper concerns the representations and reasoning mechanisms needed to construct decision models of relevance to engineered product development. Specifically, AL[E][N] description logic is proposed as a formalism for modeling engineering knowledge and for enabling retrieval and reuse of archived models. Classification hierarchies are constructed using subsumption in DL. Retrieval of archived models is supported using subsumption and query concepts. In our methodology, design decision models are constructed using the base vocabulary and reuse is supported through reasoning and retrieval capabilities. Application of the knowledge representation for the design of a cantilever beam is demonstrated.

A Dynamic 3D Geometry Compression Scheme Based on the Lifted Wavelet Transform

In distributed environments, efficient visual information sharing is critical for effective communication in real-time engineering collaboration. Methods of geometry compression are needed for high-volume geometry data distribution over networks with limited bandwidths and heterogeneous storage capacities. In this paper, a new compression scheme for time-varying 3D geometry is introduced to support engineering and scientific visualization while showing potential for the audiovisual presentation and entertainment fields. This hybrid approach allows geometric and topological information to be uniformly encoded as volume grid values then compressed based on the lifted wavelet transform. The compression ratio is significantly increased without compromising surface quality due to rescaling and integer-to-integer lifting. This approach also allows for scalability in terms of additional data streams such as color, audio, and other types of concurrent data necessary for the desired customization of this method.

Simultaneous Hierarchical and Multi-Level Optimization for Material Characterization and Design of Experiments

A hierarchical algorithmic and computational scheme based on a staggered design optimization approach is presented. This scheme is structured for unique characterization of many continuum systems and their associated datasets of experimental measurements related to their response characteristics. This methodology achieves both online (real-time) and offline design of optimum experiments required for characterization of the material system under consideration, while also achieving a constitutive characterization of the system. The approach assumes that mechatronic systems are available for exposing specimens to multidimensional loading paths and for the acquisition of data associated with stimulus and response behavior. Material characterization is achieved by minimizing the difference between system responses that are measured experimentally and predicted based on model representation. The performance metrics of the material characterization process are used to construct objective functions for the design of experiments at a higher-level optimization. The distinguishability and uniqueness of solutions that characterize the system are used as two of many possible measures adopted for construction of objective functions required for design of experiments. Finally, a demonstration of the methodology is presented that considers the best loading path of a two degree-of-freedom loading machine for characterization of the linear elastic constitutive response of anisotropic materials.

Knowledge Based Design of 3D Electronic Circuit Carriers

Miniaturization, high reliability and low manufacturing costs require close spatial integration of mechanics and electronics. New production technologies such as MID (Molded Interconnect Device), which enables to manufacture three-dimensional circuit carriers and replace conventional PCBs, open up interesting perspectives in this context. These production technologies cause strong interdependencies between product design and manufacturing; they usually determine the product concept. These interdependencies are often not known to the designers. The design of systems with technologies like MID thus needs a design-supporting knowledge base to overcome this lack of information. This paper describes a knowledge base for the design of three-dimensional electronic circuit carriers in MID. The knowledge base provides the developer with adapted procedural models for the specific design task, which show the mentioned interdependencies, as well as appropriate guidelines and standards during the different design phases. Thus the necessary information is available to the designer at all times. The application of the knowledge base is shown by the example of the housing of an autonomous miniature robot. The miniature robot is manufactured in large numbers. It serves as a test bed for swarm intelligence and multi-agents applications in computer science as well as for the employment of the Technology MID.