DETC2002/CIE-xx SUPPORTING DESIGN REFINEMENT IN MEMS DESIGN

ABSTRACT We present a framework to support design refinement during the virtual prototyping of microelectromechanical systems (MEMS). By instantiating MEMS components and connecting them to each other via ports, the designer can both configure complex systems and simulate them. We examine design refinement in the context of ease of use and representation of the virtual prototype. We propose the use of a common, formal grammar representation for the design entities in the virtual prototypeMEMS components, behavioral models and CAD models. We show that the formal grammar approach leads to easy creation of virtual prototypes. In this paper, we focus on portsthe fundamental building blocks of a virtual prototype. Ports mediate all interactions within and between aspects of the virtual prototype. For even moderately complex designs, there can be many interactions present. The representation and organization of all possible ports is important in the context of design refinement. We provide a set-theoretic formalism that defines the algebra of ports. We present a formal grammar for ports that represents a port as a set of attributes, and provide a design refinement mechanism that involves adding or modifying attributes in the port. We illustrate our framework with a MEMS example. We demonstrate that the MEMS designer can evaluate multiple design alternatives quickly and accurately with our framework. KEYWORDS Design methodology, MEMS, Simulation-based design, attribute grammars, port-based modeling, Modelica INTRODUCTION AND MOTIVATION Virtual prototyping can shorten the design cycle of MEMS products by reducing the need for expensive and timeconsuming physical prototyping. The designer can evaluate more design alternatives to obtain a better quality design. In this paper, we propose to support the process of virtual prototyping of multi-disciplinary MEMS systems. We focus our attention on those aspects of virtual prototyping that are particularly important in the context of design refinement. Specifically, we further the current state-of-the-art with respect to representation and ease of use. The system-level design process is usually top-down. The designer begins with a high-level functional description that he decomposes into sub-functions. These sub-functions are assigned to a system architecture as a configuration of components that contain both design specifications and simulation models. When further decomposition or component assignment is not desired, the designer composes the components to create a system-level configuration that is evaluated to verify the function. In this process, there are three recurring themes: composition, or combining subcomponents to create a compound component; reuse, or replacing a componen

IJTC2007-44301 AN INVESTIGATION OF THREE DIMENSIONAL ELASTIC-PLASTIC HEMISPHERICAL SLIDING CONTACT, PART I: MODELING AND VALIDAITON

ABSTRACT This work presents a three dimensional (3D) finite element analysis (FEA) of an elastic-plastic hemispherical contact model for two hemispherical bodies sliding across each other with various preset vertical interferences. The boundary conditions, model simplifications, and the normalization scheme are presented. Sample results from this FEA investigation are compared to a semi-analytical solution to validate the methodology

DETC2005-85092 A HYBRID ROD-CATENARY MODEL TO SIMULATE NONLINEAR DYNAMICS OF CABLES WITH LOW AND HIGH TENSION ZONES

ABSTRACT Cables under very low tension may become highly contorted and form loops, tangles, knots and kinks. These nonlinear deformations, which are dominated by flexure and torsion, pose serious concerns for cable deployment. Simulation of the three-dimensional nonlinear dynamics of loop and tangle formation requires a 12 th order rod model and the computational effort increases rapidly with increasing cable length and integration time. However, marine cable applications which result in local zones of low-tension very frequently involve large zones of high-tension where the effects of flexure and torsion are insignificant. Simulation of the threedimensional dynamics of high-tension cables requires only a 6 th order catenary model which significantly reduces computational effort relative to a rod model. We propose herein a hybrid computational cable model that employs computationally efficient catenary elements in high-tension zones and rod elements in localized low-tension zones to capture flexure and torsion precisely where needed

COMBINED SENSING AND ACTUATION: A NEW CONTROL LABORATORY EXPERIMENT

Abstract This paper describes a new control experiment developed for Mechanical Engineering undergraduate students. The experiment with a Shape Memory Alloy (SMA) actuated robotic arm is designed for the senior undergraduate laboratory (ME4006) in the Department of Mechanical Engineering at Virginia Tech. ME4006 is designed to provide the students with experience in experimental investigation of mechanical engineering systems. In designing this control experiment it was intended for the students to have a hands-on experiment with smart materials. Furthermore, students learn about control problems and limitations of theses materials along with sensing and actuation advantages of the SMAs. The experiment uses a problem solving approach; students are not given a procedure to follow for conducting the experiment. The problem is described in a memorandum to the students from a supervisor, who defines the purpose of the problem and defines the audience for the report. Background As smart materials are changing the practice of Engineering, providing undergraduate engineering students with experiences with these materials has become necessary. To address the educational needs, several engineering departments have developed elective courses or laboratory experiments on smart materials. California State University at Fullerton, for example, has recently established an Intelligent Systems Laboratory to provide Mechanical Engineering students with hands-on experience on integrated design and manufacturing of intelligent systems ME4006 (Experimenta

Hideyoshi Yanagisawa

Interactive Reduct Evolutional Computation for Aesthetic Design We propose a method of evolving designs based on the user's personal preferences

Minoru Taya Prediction of the In-Plane Electrical Conductivity of a Misoriented Short Fiber Composite: Fiber Percolation Model Versus Effective Medium Theory

The in-plane electrical conductivity of a misoriented short fiber composite was studied both by fiber percolation model (FPM

IJTC2007-44302 AN INVESTIGATION OF THREE DIMENSIONAL ELASTIC-PLASTIC HEMISPHERICAL SLIDING CONTACT, PART II: RESULTS

ABSTRACT This work presents the results from a three dimensional (3D) finite element analysis (FEA) of an elastic-plastic asperity contact model for two spherical bodies sliding across each other with various preset vertical interferences. Stresses, forces, contact areas, deformations, and net energy loss are presented for steel-on-steel and aluminum-on-copper contact. INTRODUCTION The methodology of elastic-plastic hemispherical sliding contact using a three dimensional (3D) finite element analysis (FEA) is presented in Part