Design Research at the School of Mechanical Engineering, Purdue University

The Design faculty and students are involved in a range of research topics that integrate basic studies leading to a fundamental understanding of mechanical systems and the design process, including the development of applications meeting industrial needs. The nine Design faculty, together with their doctoral and master’s degree students, conduct research in topics related to the design, analysis and manufacture of mechanical systems. The research areas of the Design faculty are described briefly in the following sections.

Shape Analysis and Configuration
Research is focused on efficiency and naturalness of the design process and introducing new design patterns where search and reuse are combined seamlessly together. Research includes (1) sketching computing including beautification, constraint detection, and assembly, (2) 3D and 2D shape representations for search, (3) protein surface shape representations and query mechanisms (BioCAD), (4) 3D topo-geometric methods for volume and surface decomposition, (5) clustering and classification based on shape similarity, (6) visualization and navigational interfaces for search, (7) content-based search using engineering ontologies and (7) configuration aided-design. Application areas for the research includes design advisory systems for manufacturability at design time, supply chain product search and exploration, 2D and 3D CAD model search for product lifecycle applications from concept through services and maintenance, reverse engineering, applications for cost advice in purchasing, biomedical engineering, proteomics and bioinformatics,

Robotics and automation
Research in the area of robotics and automation is conducted with a focus on kinematics, dynamics, and high-level control. Research projects include: the development of a task driven automated assembly cell which has vision, force-torque sensing, and manipulators for rapid product realization; a computer graphics simulation of this automated assembly cell to provide the designer with feedback as to the ease of assembly; the design of an intelligent pallet to convey both parts and information into the automated assembly cell; flexible fixturing concepts to allow a variety of parts to be easily fixtured using a reconfigurable fixture device; design and analysis of lightweight modular robotic devices; simulation of robotic operations in low or zero gravity environments; a real time intelligent robotic tracking system utilizing vision to locate and capture moving objects; and the coordinated motion of two planar manipulators.

Multiscale Design of Systems, Components and Materials
Research is focused on developing top-down approaches to designing complex systems from system length scales down to material microstructure length scales. Several specific issues are addressed in this research including: a) the development of a mesh-free computational analysis framework for studying changing sizes and topologies b) computationally efficient optimal shape and topology design at component length scales using the mesh-free framework c) optimal design of material microstructure to achieve required performance d) optimal design of components as well as microstructures that resist crack propagation through explicit mesh-free simulation of interactions between cracks and pores or inclusions e) probabilistic design of systems under uncertainty and e) formal frameworks for design of complex systems in a decomposed manner in which issues of data encapsulation, security, sensitivity and uncertainty are addressed.

The biomechanics research focuses on the musculoskeletal system and on biomechanical application to orthopeadics. Furthermore, studies on soft tissue as related to voice production are being conducted. Projects include studies of tendon and joint forces during repetitive activities such as piano playing and typing, bone constitutive properties, joint kinematics and contact, the effect of exercise on bone mass, prosthesis performance and wear evaluation, laboratory simulation testing of prostheses, and advanced prosthesis design methods.

Materials research focuses on mechanical behavior of materials with an emphasis on fatigue and fracture design and analysis methods. Studies include fatigue crack formation, crack propagation, life prediction methods, environment effects, high temperature effects, and thermo-mechanical fatigue. Specific applications include life prediction in machine components, failure analysis and fatigue behavior of advanced metal matrix composites, widespread fatigue damage, multi-site damage, fatigue crack formation as related to the aging aircraft problem, and fatigue crack growth analysis of integrated circuit structures and MEMS. Fatigue studies within a scanning electron microscope are focused on understanding the micro-mechanics of fatigue crack formation. Computational methods for crack growth simulation are being developed.

Kinematic analysis and synthesis of mechanisms
The primary area of research is the kinematic analysis and synthesis of planar, spherical, and spatial mechanisms. The research includes the study of theoretical and applied kinematics of single and multiple degree-of-freedom rigid body systems. An important focus is the kinematic geometry of linkages, cams, and gearing. Practical applications of the research include: analysis and synthesis of trochoidal-type mechanisms for rotary machinery, design of variable-stroke mechanisms, analysis of serial and parallel-type robotic manipulators and design of cooperating robot work cells. Technical publications focus on the design and analysis of reciprocating and rotary machinery and the inverse kinematics and dynamics of single industrial-type robot manipulators and multiple cooperating robots. The archival publications appear in the Transactions of ASME and SAE, the International Journal of Robotics Research, and Mechanism and Machine Theory.

Experimental and analytical studies in tribology
Research projects in lubrication, friction, and wear of tribo-contacts involve experimental and analytical research on debris effects in lubricated contacts, evaluation of frictional characteristics of wed clutches, wear and friction of high temperature lubricants, in situ pressure and temperature measurements of tribo-contacts, high speed lip seal design, and computer-aided design and graphical display of tribo-elements.

Vehicle simulation and design methods
Research is being conducted to advance the state of the art in modeling and control of the dynamics of highway and specialty vehicles through experimental and theoretical research. Projects include: a study of the effects of vehicle design parameters, such as tire models and roll center locations, on limit performance, including handling, acceleration, and braking; development of phenomena-based models of lateral and fore-aft tire force generation, and electronically controlled transmission systems for utility and hybrid vehicles.

Computer-aided design (CAD) and computer graphics
Research in CAD and graphics addresses new concepts for using the computer as a tool in the product realization process. This includes the design, analysis and manufacture of parts and assemblies, with emphasis on computer-aided design and computer graphics applications. CAD research topics involve advanced design methods and shape representation, including high-level shape design, intelligent design and analysis, computational geometry, solid modeling, and free-form surface design. Research in computer graphics includes scientific visualization, interactive 3D design methods, and graphic system development.

A number of research laboratories provide state-of-the-art facilities for Design research projects:

The PRECISE Center is focused on developing new next generation product realization frameworks. Activities encompass the entire product lifecycle from design through service, maintenance and retirement. These include integration of research activities of faculty in a number of diverse areas in science and engineering.

The ConfigLab and ShapeLab Laboratories are core research activities in PRECISE. They support computational platforms, servers and databases using high end computational infrastructure for shape analysis and configuration research. Shapelab also hosts a shape search benchmark for downloading parts and testing new algorithms as well as a web-based sketch search prototypes.

The Hierarchical Design and Characterization Laboratory supports research applied to solve microelectronics related problems including developing nanostructured particulate thermal interface materials, characterizing the fracture behavior of low-k dielectric films, characterizing creep and high strain rate behavior of lead-free SnAgCu solder alloys, modeling (using cohesive zone theory) and experimentally characterizing fatigue fracture at SnAgCu solder joint interfaces, stochastic modeling and design of fiber-optic systems, developing thermodynamically consistent multiphysics models of stress and electromigration in interconnects. The equipment available in the lab includes a Nanonics Multiview 3000 dualprobe Nanoindenter/AFM, an Instron 5848 Micromechanical tester with Eurotherm EC 1615 environmental chamber, Thermotron 2800 Environmental Test Chamber, Linkam THMS 600 thermal stage and controller, a Photomechanics PEMI I four-beam laser Moire interferometer, a Nikon SMZ 1500 microscope and other metallographic sample preparation equipment.

The Biomechanics Laboratory provides facilities for studying the biomechanics of the musculoskeletal system, orthopaedic biomechanics, and prosthesis design and evaluation. Included in the laboratory are a hydraulically controlled, four-channel knee simulator for evaluating total knee prostheses and several PC-based instrumentation systems. Two servo-hydraulic test systems also are available for use by the Biomechanics Laboratory.

The Materials Testing Laboratory is a facility for investigating the mechanical behavior of materials with particular emphasis on fatigue, fracture, and dynamic behavior. Included in the laboratory are two servohydraulic test systems and a thermo-mechanical fatigue testing facility. Also available for materials research is an environmental scanning electron microscope with a fatigue loading stage and high temperature stage.

The Microstructure Analysis and Testing Laboratory is a facility for testing materials at low forces. Special focus is on investigation of IC and MEMS related structures, thin films, and soft tissue-inspired materials. Equipment includes an electro-dynamically actuated mechanical test system for combined tensile and torsional testing, an in-situ piezo-actuated test system, digital image correlation analysis, a system for the stereo-photogrammetric analysis of fracture surfaces, and various options for microscopy.

The Mechanical Engineering Robotics Laboratory supports research in the areas of manipulators and automation, with projects in obstacle avoidance, vision-guided tracking, cooperating robots, and manipulation in hazardous low gravity environments. Equipment includes a computer controlled three-degree-of-freedom planar manipulator with air bearing supports and a computer controlled two-degree-of-freedom manipulator with a direct-drive joint.

The Mechanical Engineering Tribology Laboratory is a facility dedicated for fundamental studies of friction, lubrication, wear and dynamics of rolling and sliding contacts. The laboratory also has been involved in micro-mechanical sensor development for tribological applications. The laboratory is well equipped with various machines for fundamental tribology studies. These include: an optical ball-on-flat apparatus for film thickness measurements, a multi-purpose multi-specimen Falex machine, a bearing fatigue testing machine, an optical surface profilometer, a bearing testing machine, a wet clutch testing machine, a dynamic brake testing machine, a pin on disk machine, an RF sputter coating machine, a RR Moore fatigue testing machine, a three ball and rod rolling fatigue testing machine, a thrust washer test rig, a journal bearing test rig, a twin disk machine, new multi-channel data acquisition hardware and software, and a number of work stations for data acquisition and computing.