bluuebunny/crossref_metadata_2025 huggingface dataset:
In-Plane Flexible Ring Tire Model Validation Through ADAMS FTire Model Virtual Tests
Authors: Li Bin , Yang Xiaobo , Jin Ankang , Zhang Yunqing , Yang James
Published: January 2016

This paper presents the validation for the newly developed in-plane flexible ring tire model by using ADAMS FTire model simulation. The developed in-plane model is unique in two aspects: (1) the neighboring belt segments are connected through normal and tangential directions by springs and dampers, each belt segment is a rigid body and its mass is accumulated at its geometric center. Each belt segment is always perpendicular to the line formed by the wheel center and the belt geometric center, thus there is no rotational constrains between the neighboring belt segments; (2) the representation of the tangential friction force between the tire and the road is defined through the multiplication of the normal contact force and the friction coefficient. And the friction coefficient is obtained based on an empirical model of the tire slip. For validation, a quarter-car model first runs on a flat road with a constant velocity (40km/h) and then rides over a rectangular shape obstacle to identify the tire parameters based on the virtual tests of Gipser’s FTire model in ADAMS. Then the quarter-car model runs on a flat road with 4–5 different conditions to ride over each obstacle: rectangular shape, triangular shape, half circle, and trapezoid. Simulation results for the new in-plane flexible ring model are compared with virtual test results from ADAMS FTire model on the same road and velocity condition for the tire patch contact forces in horizontal and longitudinal directions respectively based on the SAE standard J2812. Note that this study is the first time that the new SAE standard J2812 is used for model validation. After the validation, two important aspects have been investigated: (1) What is the minimum height of each obstacle shape so that the parameter identification will have minimum equipment loads? (2) What should the minimum number of belt segments be for each obstacle shape? The above two aspects are useful for tire model end users and tire experimental experts in real world applications.
Design and Build for Gondwanna: A Course in Mechanical and Electronic Design
Authors: Smith Warren F.
Published: January 2016

The subject course has as its central focus a design and build project that draws its context from addressing problems faced by a mythical Gondwannan population. Through it, students are exposed to an authentic design experience across a range of technical domains in an integrated semester long process. They grapple with user needs, requirements analysis, concept and detail design reviews and prototype demonstration. The course, as run at the University of New South Wales, Canberra, is described in the paper and the facilitation of the course academically and physically is discussed.
A Variable-Stiffness Straight-Line Compliant Mechanism
Authors: Hawks Jeffrey C. , Colton Mark B. , Howell Larry L.
Published: January 2016

In this research a variable-stiffness compliant mechanism was developed to generate variable force-displacement profiles at the mechanism’s coupler point. The mechanism is based on a compliant Robert’s straight-line mechanism, and the stiffness is varied by changing the effective length of the compliant links with an actuated slider. The force-deflection behavior of the mechanism was analyzed using the Pseudo-Rigid Body Model (PRBM), and two key parameters, KΘ and γ, were optimized using finite element analysis (FEA) to match the model with the measured behavior of the mechanism. The variable-stiffness mechanism was used in a one-degree-of-freedom haptic interface (force-feedback device) to demonstrate the effectiveness of varying the stiffness of a compliant mechanism. Unlike traditional haptic interfaces, in which the force is controlled using motors and rigid links, the haptic interface developed in this work displays haptic stiffness via the variable-stiffness compliant mechanism. One of the key features of the mechanism is that the inherent return-to-zero behavior of the compliant mechanism was used to provide the stiffness feedback felt by the user. A prototype haptic interface was developed capable of simulating the force-displacement profile of Lachman’s Test performed on an injured ACL knee. The compliant haptic interface was capable of displaying stiffnesses between 4200 N/m and 7200 N/m.
Assessment of Design and Build Projects in Sophomore Design
Authors: Bannerot Richard
Published: January 2016

One requirement in our sophomore design class is for the students to work in teams to design and build devices that satisfy several requirements subject to physical constraints. The evaluation of these devices is based on how individuals and the team perform on written documents as well as how well the device performs during testing and satisfies given design criteria. The performances in various parts of this assignment are used as a basis for student outcomes assessment. The paper will provide an example of a team project description including the figure of merit that assesses the functionality of the device and the rubric used to assess the quality of the design in four areas:

• creativity demonstrated in the design concept,

• creativity demonstrated in the execution of the concept,

• overall craftsmanship and esthetics, and,

• robustness,

plus a sales brochure.

Examples of student work and assessment documentation will also be provided.
Sensing and Force-Feedback Exoskeleton Robotic (SAFER) Glove Mechanism for Hand Rehabilitation
Authors: Ma Zhou , Ben-Tzvi Pinhas , Danoff Jerome
Published: January 2016

This paper presents the design and application of the SAFER glove in the field of hand rehabilitation. The authors present preliminary results on a new hand grasping rehabilitation learning system that is designed to gather kinematic and force information of the human hand and to playback the motion to assist a user in common hand grasping movements, such as grasping a bottle of water. The fingertip contact forces during grasping have been measured by the SAFER Glove from 12 subjects. The measured fingertip contact forces were modeled with Gaussian Mixture Model (GMM) based on machine learning approach. The learned force distributions were then used to generate fingertip force trajectories with a Gaussian Mixture Regression (GMR) method. To demonstrate the glove’s potential to manipulate the hand, experiments with the glove fitted on a wooden hand to grasp various objects were performed. Instead of defining a grasping force, contact force trajectories were used to control the SAFER Glove to actuate/assist this hand while carrying out a learned grasping task. To prove that the hand can be driven safely by the haptic mechanism, force sensor readings placed between each finger and the mechanism have been plotted. The experimental results show the potential of the proposed system in future hand rehabilitation therapy.
Applications of the 4D Geometric Algebra to Dimensional Mobility Criteria of Delassus-Parallelogram and Bennett Paradoxical Linkages
Authors: Lee Chung-Ching
Published: January 2016

Geometric algebra is also termed Clifford-Grassmann algebra or hypercomplex number. It allows studying space geometric problems in an easy and compact way. Transforming three-dimensional (3D) Euclidean geometric entities to actual elements of four-dimensional (4D) geometric algebra (abbreviated to g4) through a methodical approach of geometric algebra, one can describe motion displacements as even elements of g4. This article relies on the combined rotation and translation in g4 to establish the dimensional constraints of two non-exceptional overconstrained paradoxical linkages. Firstly, fundamentals of geometric algebra are recalled. Then, the single finite rotation and the composition of two successive finite rotations are introduced. After that, a general rigid-body motion in g4 is revealed for a possible application in exploring paradoxical chains using the geometric algebra. Finally, the metric or dimensional mobility criteria of Delassus-parallelogram four-screw and Bennett four-revolute paradoxical linkages are algebraically verified.
Axial Crushing of Thin-Walled Tubes With Kite-Shape Pattern
Authors: Hou Degao , Chen Yan , Ma Jiayao , You Zhong
Published: January 2016

Thin-walled tubes are widely used as energy absorption devices in automobiles, designed to protect the costly structures and people inside during an impact event through plastic deformation. They show excellent performance under axial loading in terms of weight efficiency, stroke distance and total energy absorption, but also have the disadvantage that the crushing force is not uniform during deformation process, especially with the existence of a high initial peak force. Recently, pattern design on tubular structures has received increasing attention. It has been found that, if the surface of a tube is pre-folded according to an origami pattern, the collapse mode of the tube can be altered, leading to changes in energy absorption performance. In this paper, we present a series of origami patterned tubes with a kite-shape pattern that is constructed by joining two pieces of Miura-ori. First of all, the geometry of the pattern is presented. We develop a theoretical model to predict the energy absorption associated with the axial crushing of the patterned tubes and derive a mathematical formula to calculate the mean crushing force accordingly. Secondly, a family of origami tubes with various profiles are designed, and their performances subjected to quasi-static axial crushing are numerically investigated.

A parametric study is also conducted to establish the relationship between the pre-folded angle of the pattern and the initial peak force as well as the mean crushing force. Numerical results show that introducing patterns to thin-walled tubes offers three advantages in comparison with conventional tubes, i.e., a lower initial peak force, a more uniform crushing load, and a stable and repeatable collapse mode. A 36.0% increase in specific energy absorption and 67.2% reduction in initial peak force is achieved in the optimum case. The new origami patterned tubes show great promise as energy absorption devices.
The Design and Optimization of a New Bluff Body of the Electromagnetic Vortex Flowmeter Based on ISIGHT
Authors: He Xu , Zhen Li , Yixian Xu , Hongpeng Yu
Published: January 2016

Bluff body plays a significant role in the electromagnetic vortex flowmeter. More reasonable structure and size of the bluff body can generate more strong and stable vortex shedding for the better sensor measurement. Currently, the optimization for the size of the bluff body is that dispersing the parameter interval and comparing the different size combinations by many researchers. In this method, the result may be the local optimum easily, and the process is same that the simulation is a waste of time for the vortex shedding in the different sizes of the bluff body more or less. However, a new kind of bluff body and an optimization method are proposed in this paper. By means of the NSGA-II algorithm, the size of the bluff body is optimized in the ISIGHT software integrated of Gambit, Fluent and Excel in different Reynolds numbers conditions. At last, we obtained the reasonable size of the bluff body in a wide range of the Reynolds number (2.9×103∼6×104).
Variable Motion/Force Transmissibility of a Metamorphic Parallel Mechanism With Reconfigurable 3T and 3R Motion
Authors: Gan Dongming , Dai Jian S. , Dias Jorge , Seneviratne Lakmal D.
Published: January 2016

This paper presents a metamorphic parallel mechanism which can switch its motion between pure translation (3T) and pure rotation (3R) motion. This feature stems from a reconfigurable Hooke (rT) joint of which one of the rotation axes can be altered freely. More than that, based on the reconfiguration of the rT joint, workspace of both 3T and 3R motion can be tunable and the rotation center of the 3R motion can be controlled along a line perpendicular to the base plane. Kinematics analysis is presented based on the geometric constraint of the parallel mechanism covering both 3T and 3R motion. Following these screw theory based motion/force transmission equations are obtained and their characteristics are investigated and linked to the singularity analysis using Jacobian matrix. Motion/force transmission indices can be used to optimize basic design parameters of the metamorphic parallel mechanism. This provides reference of this mechanism for potential applications requiring 3T and 3R motion.
Fabrication of Polymer Origami-Based V-Type Folded Core
Authors: Zhao Danyang , Li Yujie , Wang Minjie , Duan Chunzheng , You Zhong
Published: January 2016

The origami-based folded core has a broad prospect in applications. However, the fabrication difficulties limit its developments due to the complicate structures with multiple zigzags and fluctuations. In this study, several feasible methods to fabricate polymer origami-based folded core were proposed. Based on the analysis of folded structural features, the vacuum forming process of polymer V-type folded core was deeply investigated. Wall thickness distributions of the folded structure on polyvinyl chloride (PVC) and polyethylene terephthalate (PET) sheets were measured. The results showed that the wall thickness along the straight crease line presents a single peak distribution, while that along the zigzag one shows a dual peak distribution, and the wall thickness of the top zigzag crease line is more uniform and large than that of the bottom one. The mold temperature, polymer sheet temperature and material properties of polymer have great influence on product thickness. Vacuum forming is a feasible way to fabricate polymer origami-based folded core, and the high-quality fabrication of folded structure may be accomplished by designing more reasonable forming mold and selecting optical process parameters.
A Text Mining Technique for Manufacturing Supplier Classification
Authors: Yazdizadeh Peyman , Ameri Farhad
Published: January 2016

The web presence of manufacturing suppliers is constantly increasing and so does the volume of textual data available online that pertains to the capabilities of manufacturing suppliers. To process this large volume of data and infer new knowledge about the capabilities of manufacturing suppliers, different text mining techniques such as association rule generation, classification, and clustering can be applied. This paper focuses on classification of manufacturing suppliers based on the textual description of their capabilities available in their online profiles. A probabilistic technique that adopts Naïve Bayes method is adopted and implemented using R programming language. Casting and CNC machining are used as the examples classes of suppliers in this work. The performance of the proposed classifier is evaluated experimentally based on the standard metrics such as precision, recall, and F-measure. It was observed that in order to improve the precision of the classification process, a larger training dataset with more relevant terms must be used.
Skin Model Shapes: Offering New Potentials for Modelling Product Shape Variability
Authors: Schleich Benjamin , Wartzack Sandro , Anwer Nabil , Mathieu Luc
Published: January 2016

The modelling of nominal product geometry by computer-aided design tools has gained immense attention in industry during the last decades and is nowadays an integral part of the virtual product development process. However, the established geometry representation schemes for CAD imply severe drawbacks regarding the modelling of geometric part deviations, which are inevitably observed on every manufactured artefact. As a response, the concept of Skin Model Shapes, which stems from international standards for geometric product specification and verification, has been developed as a novel approach for the consideration of product shape variability. It employs discrete geometry methods and computational techniques, such as point clouds, surface meshes and geometric processing, to model shape variability and to facilitate the communication of geometric product information throughout the product design, manufacturing, and inspection processes. This paper highlights the foundations of this concept, demonstrates its potentials for the representation of product geometry considering geometric variations along the product lifecycle, and illustrates main applications in the context of computer aided product and process development. In this regard, a focus is laid upon recent results and contributions, such as contact modelling, tolerance analysis, and motion tolerancing based on Skin Model Shapes. Furthermore, challenges for future research, such as the application to complex shapes and compliant parts, as well as the consideration of novel manufacturing processes, are discussed.
A SysML-Based Modeling Language for Mechatronic System Architecture
Authors: Chen Ruirui , Liu Yusheng , Cao Yue , Xu Jing
Published: January 2016

Model Based Systems Engineering (MBSE) is the mainstream methodology for the design of complex mechatronic systems. It emphasizes the application of the system architecture, which highly depends on a formalized modeling language. However, such modeling language is less researched in previous studies. This paper proposes a general modeling language for representing the system architecture, aiming for representing function, physical effect, geometric information and control behavior which the system should satisfy. It facilitates the communication of designers from different technological domains and supports a series of applications such as automatic reasoning, system simulation, etc. The language is illustrated and verified with a practical mechatronic device finally.
State-Dependent, Non-Smooth Model of Chatter Vibrations in Turning
Authors: Lehotzky Dávid , Insperger Tamás , Stépán Gábor
Published: January 2016

This paper deals with the modeling and analysis of the cutting tool’s global dynamics in the orthogonal cutting process of turning operations considering the effect of state dependency and fly-over in one model. In particular, the one-degree-of-freedom non-smooth model, presented by Wahi and Chatterjee in 2008, is extended by the consideration of vibrations in the direction perpendicular to the feed velocity. This results in the state-dependency of the model and gives an additional direction in which fly-over can occur. The constructed mathematical model consists of a nonlinear PDE, which describes the evolution of the surface height of the workpiece and a two-degree-of-freedom ODE, which governs the motion of the tool. The PDE is connected to the solution of the ODE by a non-local, non-smooth boundary condition. For the case when the tool is within the cut, this model gives the conventional model of turning governed by delay-differential equations with state-dependent delays. In order to study the effect of vibrations in the tangential direction numerical simulations are carried out and their results are compared to the model presented by Wahi and Chatterjee (2008).
Cartan’s Connection, Fiber Bundles and Quaternions in Kinematics and Dynamics Calculations
Authors: Colón Diego
Published: January 2016

It is used the concept of Cartan’s connection and principal fiber bundles to obtain formulas for kinematics and dynamics calculations for robotic manipulators. A principal fiber bundle is a differentiable manifold formed by a base space B (in this case ℝ3)) plus all possible reference frames attached to a point p ∈ B (that is the fiber Sp). Cartan’s connections are the most general way to represent velocity of frames. In previous works, those ideas were applied to fiber bundles with fibers homomorphic to the Lie group SO(3) (or SE(3)). In this paper, it is applied to the case of fibers homomorphic either to the group SU(2) (for rotational motion) or to the group of unit dual quaternions (for translational plus rotational motion). It is also presented some results of calculations, and indicate future directions for research.
A Method for Visualizing the Relations Between Grammar Rules, Performance Objectives and Search Space Exploration in Grammar-Based Computational Design Synthesis
Authors: Königseder Corinna , Shea Kristina
Published: January 2016

Design grammars have been successfully applied in numerous engineering disciplines, e.g. in electrical engineering, architecture and mechanical engineering. A successful application of design grammars in Computational Design Synthesis (CDS) requires a) a meaningful representation of designs and the design task at hand, b) a careful formulation of grammar rules to synthesize new designs, c) problem specific design evaluations, and d) the selection of an appropriate algorithm to guide the synthesis process. Managing these different aspects of CDS requires not only a detailed understanding of each individual part, but also of the interdependencies between them. In this paper, a new method is presented to analyze the exploration of design spaces in CDS. The method analyzes the designs generated during the synthesis process and visualizes how the design space is explored with respect to a) design characteristics, and b) objectives. The selected algorithm as well as the grammar rules can be analyzed with this approach to support the human designer in successfully understanding and applying a CDS method. The case study demonstrates how the method is used to analyze the synthesis of bicycle frames. Two algorithms are compared for this task. Results demonstrate how the method increases the understanding of the different components in CDS. The presented research can be useful for both novices to CDS to help them gain a deeper understanding of the interplay between grammar rules and guidance of the synthesis process, as well as for experts aiming to further improve their CDS application by improving parameter settings of their search algorithms, or by further refining their design grammar. Additionally, the presented method constitutes a novel approach to interactively visualize design space exploration considering not only designs objectives, but also the characteristics and interdependencies of different designs.
Unit Manufacturing Process Models for Ferromagnetic and Non-Ferromagnetic Alloy Surface Inspection Methods
Authors: Garretson Ian C. , Lyons Kevin W. , Mani Mahesh , Leong Swee , Carter Matthew D. , Simmons Ann E. , Haapala Karl R.
Published: January 2016

Industrial use of natural resources are increasing at an alarming rate. Engineering and decision support tools are needed for analyzing and curbing industrial consumption of resources. Further, assessment methods to measure and indicate continuous improvement are also needed. Modeling individual manufacturing processes facilitates the generation of quantifiable evidence that improvements are being made. Such a modeling approach is developed and demonstrated in this paper to characterize sustainability performance of two metals inspection processes: magnetic particle inspection for ferromagnetic alloys and penetrant inspection for non-ferromagnetic alloys. Individual unit manufacturing process (UMP) models were developed by observing the inspection practices at an aircraft component manufacturer, and a mathematical basis for comparison with other inspection processes was identified. The paper further demonstrates the aggregation of performance metrics from all UMPs across a manufacturing process flow thus providing a basis for generating detailed sustainability performance assessments of manufactured products. By developing and documenting a comprehensive set of UMP models, more complete knowledge of manufacturing processes can be gained by industry practitioners, leading to continuous improvement of sustainability performance.
A Method for Identification of the Constitutive Law of Biological Filaments From Their Dynamic Equilibria
Authors: Fatehiboroujeni Soheil , Goyal Sachin , Gramada Apostol
Published: January 2016

There are several biological filaments that play vital role in cellular processes via twisting and bending deformations. From the double-stranded DNA molecule containing genetic information to the cytoskeletal fibers that provide shape to the cell, biological filaments undergo conformational changes as they perform their biological tasks. Therefore the ability of a filament to deform, which depends on their atomistic structure, is a characteristic property that governs its biological functions. Since there is no direct analytic method to derive the deformability or constitutive law of such filaments from their atomistic structure, the constitutive law has to be identified from their actual deformations. An inverse approach based on a continuum rod model was developed recently that uses deformations in static equilibrium to estimate the constitutive law in bending and torsion. We extend the inverse method to use dynamic states of deformations, and consequently expand its scope to leverage a wide variety of choices in molecular dynamics simulations for identifying the constitutive law. This paper presents and validates the technique applying it to filaments with artificial atomistic structure.
Constraint Stiffness Construction and Decomposition of a SPS Orthogonal Parallel Mechanism
Authors: Qiu Chen , Dai Jian S.
Published: January 2016

This paper investigates both stiffness analysis and synthesis problems using a physical prototype of one SPS orthogonal parallel mechanism. This parallel mechanism is supported with line-type constraint limbs. In the stiffness analysis, a reciprocal relationship between motions and wrenches is used to design layouts of constraint limbs and construct the corresponding stiffness matrix. In the stiffness synthesis, the developed stiffness matrix is decomposed to obtain configurations of constraint limbs based on existing synthesis algorithms, including direct-recursion and matrix-partition approaches. It is revealed the line-vector based matrix-partition approach can establish an one-to-one correspondence between synthesized results and constraint limbs of the parallel mechanism. Subsequently both types of synthesis approaches are applied to decomposing the developed constraint stiffness matrix. The comparison results suggest the modified matrix-partition approach can obtain decomposed constraint limbs exactly the same as those used to construct the stiffness matrix.
A Fully Compliant Constant Velocity Universal Joint
Authors: Machekposhti D. Farhadi , Tolou N. , Herder J. L.
Published: January 2016

This paper presents the concept and fabrication of a large deflection compliant Constant Velocity universal joint (CV joint). A novel compliant structure is proposed based on the 6R Hybrid spatial overconstrained linkage. Due to symmetry, its kinematic properties are such that can transfer rotational motion between two angled shafts with true constant velocity. The kinematic of the mechanism and the Pseudo-Rigid-Body model of its compliant configuration are studied and analyzed. A prototype was manufactured and experimentally evaluated. It was verified that the experimental results are consistent with the theoretical expectations.
Kineto-Elastic Analysis of a Compound Bow
Authors: Yang Ming , Lin Yuyi , Jin Xiaoyi
Published: January 2016

This paper presents the kineto-elastic analysis of a compound bow which in each side of the limbs has two stacked eccentric cams connected by two inextensible cables and one inextensible string. A large deformation cantilever beam model was created to determine the center trajectories of the cams. The principle of finite element method was applied to calculate the deformation of the limbs by combining small deflections of segmented cantilever beam elements. Another part of this work is the construction of a quasi-static model to simulate the draw process. The displacements of cams, cables and string were analyzed by gradually drawing the bow string. The required draw force as a function of draw length was obtained, and verified by experiments. The kineto-elastic analysis procedure described in this paper can be used later for the optimal design of the shapes of the cams and limbs. The modeling and simulation procedure used for combining elastic components, flexible but inextensible string-cable components, and rigid component in a precision dynamic model of a mechanical system can also be applied to archery bows with more complex configuration, and to other similar mechanical systems.
Material Characterization of Additively Manufactured Part via Multi-Level Stochastic Upscaling Method
Authors: Gorguluarslan Recep M. , Park Sang-In , Rosen David W. , Choi Seung-Kyum
Published: January 2016

An integrated multiscale modeling framework that incorporates a simulation-based upscaling technique is developed and implemented for the material characterization of additively manufactured cellular structures in this paper. The proposed upscaling procedure enables the determination of homogenized parameters at multiple levels by matching the probabilistic performances between fine and coarse scale models. Polynomial chaos expansion is employed in upscaling procedure to handle the computational burden caused by the input uncertainties. Efficient uncertainty quantification is achieved at the mesocale level by utilizing the developed upscaling technique. The homogenized parameters of mesostructures are utilized again at the macroscale level in the upscaling procedure to accurately obtain the overall material properties of the target cellular structure. Actual experimental results of additively manufactured parts are integrated into the developed procedure to demonstrate the efficacy of the method.
The Kinematic Design of the Parallel Motion Simulator With Spherical-Translation Movement
Authors: Qu Yufeng , Yu Jingjun , Zong Guanghua , Bi Shusheng
Published: January 2016

A motion simulator is a type of equipment which can reproduce the actual movement environment for an object. It can be widely used in various occasions. Current motion simulator mainly utilizes the full degree-of-freedom (DOF) parallel mechanisms (PMs), such as the Stewart platform, as the main body of the machine. In fact, there is no need to use the full-DOF mechanism at the most of the time. Some deficient-DOF mechanisms can also meet the demands of certain motion simulation. Especially for some predefined motion patterns, the dedicated equipment is more capable and convenient to use than the universal one. In this paper, a practical types of motion simulators for testing the performance under the spherical-translation motion is presented. Specifically, the orientation of the tested object remains fixed during the whole process in order to fulfill the certain simulation demand. First of all, the motion and constraint characteristics for the spherical-translation movement are brought forward using a graphical approach. Based on these conditions, a typical parallel mechanism 3-UU with desired motion pattern is taken out in further to verify the constraint conditions above. Besides, the architecture of each limb is analyzed to observe the necessary condition that the structure characteristics should satisfy. Furthermore, its functional limitation in simulating the spherical-translation motion in random direction is also proposed. According to all the architecture features retained by the mechanism, the new types of motion simulator outputting the desired movement is synthesized and designed at the last, which has been categorized for different application fields.
Axode Characteristic of 4-4R Parallel Pointing Mechanism
Authors: Duan Zhixiang , Yu Jingjun , Kong Xianwen
Published: January 2016

Axodes of a spatial mechanism can reveal plenty of information about its motion characteristic. Through the research of the axodes, the mechanism’s motion patterns can be more intuitively understood, which provides lots of help to exploring its further application. However, compared with one-DOF (degree of freedom) spatial mechanism, the research on axodes of multi-DOF PMs (parallel mechanisms) is scarce. Thus, this paper mainly investigates the axodes of a typical 2-DOF rotational PM, i.e. the 4-4R pointing mechanism, also called as Omni Wrist III, and further discloses its distinctive rolling characteristics. The final objective is to extend the application of the 4-4R pointing mechanism based on its axode characteristic. For this purpose, a rapid graphic-based algorithm for calculating the fixed and moving axodes of the 4-4R pointing mechanism is presented considering its particular geometrical arrangement. Based on the algorithm and further axode analysis, three special motion patterns existing in the mechanism, i.e. pure conical rolling, pure cylindrical rolling and pure spherical rolling, are disclosed. According to its axodes characteristic, the application of the 4-4R pointing mechanism can be extended to design of new spherical gears and constant-velocity couplings, etc.
Coupled Electrostatic-Structural Analysis Using Mesh Independent Approach
Authors: Mishra Pushkar , Kumar Ashok V.
Published: January 2016

Coupled electrostatic-structural interaction needs to be modeled for designing many electrostatically actuated devices such as MEMS switches, accelerometers and comb-drives. The models for such devices must include an assembly of components and the air gaps between them. The electrostatic fields are generated in the air gaps and this field produces electrostatic forces which act on the structural components causing deformation and strains. Generating an appropriate mesh for such an assembly of regions with different material properties can be cumbersome. In this paper, we have developed an immersed boundary approach where the geometry is defined using the equations of the boundary and is immersed in a uniform background mesh. The loads and boundary conditions are imposed using the implicit boundary method since the nodes of the background mesh are not guaranteed to be on the boundaries. This approach is verified by applying it to commonly used examples.
Teaching Interdisciplinary Design Between Architecture and Engineering: Finding Common Ground While Retaining Disciplinary Expertise
Authors: Li Timothy , Raghunath Nilanjan , Hölttä-Otto Katja , Arpak Asli , Nanayakkara Suranga , Telenko Cassandra
Published: January 2016

Many educators agree that developing an interdisciplinary design curriculum is critical in creating the next generation of design professionals. However, literature surrounding the pedagogical challenges to undergraduate interdisciplinary design courses is limited. In this paper we study the initial challenges in developing and delivering an interdisciplinary design course. We observe from the perspective of the educators and the students in a newly synthesized co-taught design course that combines both architecture and engineering disciplines.

Through exploratory observations and analysis of student and instructor feedback throughout the semester, our findings suggest that disciplinary boundaries often influence pedagogical styles despite a concerted effort to create an interdisciplinary course that focuses on design. Despite agreement to interdisciplinary design teaching through shared lectures and activities, individual teaching methods varied, impacted by pedagogical norms from their respective disciplines. In response, students had mixed reactions to the varying presentation methods and critique feedback. This study, while preliminary in assessment, raises many questions about the challenges of teaching interdisciplinary design courses.
Assessment of Products Future Reusability Based on Consumers Usage Behavior: Implications for Lithium-Ion Laptop Batteries
Authors: Sabbaghi Mostafa , Esmaeilian Behzad , Raihanian Mashhadi Ardeshir , Cade Willie , Behdad Sara
Published: January 2016

Product reuse is a recommended action toward sustainability. However, the profitable reusability of End-of-Use or End-of-Life (EoU/L) products depends on how consumers have used them over the initial lifecycles and what are their EoU conditions. In addition to consumers’ behavior, product design features such as product durability has an impact on the future reusability. In this paper, a data set of Lithium-ion laptop batteries has been studied with the aim of investigating the potential reusability of laptop batteries. This type of rechargeable batteries is popular due to their energy efficiency and high reliability. Therefore, understanding the lifetime of these batteries and improving the recycling process is becoming important. In this paper, the reusability assessment is linked to the consumer behavior and degradation process simultaneously through monitoring the performance of batteries over their lifetimes. After capturing the utilization behavior, the performance-based stability time of batteries is approximately derived. Consequently, the Reusability Likelihood of batteries is quantified using the number of cycles that the battery can be charged with the aim of facilitating future remarketing and recovery opportunities.
Nonlinear Effects of Bone Damping on Human Postural Balance
Authors: Shukla Amit , Bhattacharya Amit
Published: January 2016

Osteoporosis is a common disease in women over the age of 50. The detection of this disease is done by an expensive bone mineral density test using dual energy x-ray absorpiometry. Osteoporosis patients are at a high risk of bone fracture under daily living conditions. Previous studies have shown that natural shock absorption capability of human body suffering from osteoporosis is significantly impaired.

This study is to develop an understanding of nonlinear effects of osteoporosis on human postural balance via computational models developed to capture changes in the shock absorption capabilities of human musculoskeletal system in osteoporosis patients. This paper uses a previously published, time delayed model of human postural balance by simulating the effect of osteoporosis via changes in damping factor. Numerical studies are presented and results interpreted to capture and highlight the nonlinear effects of osteoporosis on the dynamics postural balance response. This approach, upon further clinical evaluation can result in utilization of human postural balance test and the corresponding non-invasive Bone Shock Absorption test and measurement techniques for detection of osteoporosis.
An Integrated Approach to Product Family Redesign Using Commonality and Variety Metrics
Authors: Jung Sangjin , Simpson Timothy W.
Published: January 2016

Redesigning a product family entails carefully balancing the tradeoffs between commonality and differentiation that are governed by the underlying platform architecture. Numerous metrics for commonality and variety exist to support product family design; however, rarely are they used in concert to redesign platforms effectively. In this paper, we introduce an integrated approach using multiple product family metrics to establish an effective platform redesign strategy. Specifically, we present a detailed procedure to integrate the Generational Variety Index (GVI), Product Line Commonality Index (PCI), and Design Structure Matrix (DSM) to prioritize components for redesign based on variety and commonality needs. The integrated approach extends to the platform architecture and establishes a redesign strategy for interfaces between components in the platform architecture. To demonstrate the approach, case studies involving two generations of wireless computer mice and two families of dishwashers are presented. Ongoing and future work are also discussed.
Topology Optimization With Load Uncertainty as an Inhomogeneous Eigenvalue Problem
Authors: Song Wei , Lee Euihark , Gea Hae Chang , Xu Limei
Published: January 2016

In this paper, a non-probabilistic based topology optimization method under an external load uncertainty is presented. In traditional topology optimization problems, external loadings that apply to structures are always assumed as deterministic, but an external loading with uncertainties is very common in many practical engineering applications. In this paper, load uncertainty is described as an unknown-but-bounded model and the maximum possible strain energy based topology optimization formulation under an uncertain load is solved for the worst case condition. This optimization problem can be rewritten as a two-level optimization problem: the upper level optimization problem is a deterministic topology optimization under a critical loading of the worst structure response, and the lower level optimization problem is to determine the critical loading corresponding to the worst structure response.

The challenge of the lower level optimization problem is on its non-convexity which makes many gradient based search methods ineffective. To overcome this issue, the lower level optimization problem is reformulated based on the KKT optimality conditions as an inhomogeneous eigenvalue problem and is solved for the critical loading corresponding to the worst structure response. After the worst loading case is identified, the upper level problem can be solved through the existing gradient based optimization algorithms. The effectiveness of the proposed topology optimization under unknown-but-bounded external loading uncertainty is demonstrated through a few numerical examples.
Damping Characteristics of a Hydraulic Electric Rectifier Shock Absorber and its Effect on Vehicle Dynamics
Authors: Xu Lin , Liu Yilun , Guo Sijing , Guo Xuexun , Zuo Lei
Published: January 2016

Many energy-harvesting shock absorbers have been proposed in recent years, the most popular design is the electromagnetic harvester including linear electromagnetic shock absorbers, rotational electromagnetic shock absorbers, the mechanical motion rectifier (MMR), and the hydraulic-electromagnetic energy-regenerative shock absorber (HESA). With different energy converting mechanisms, the complicated effects of the inertia and nonlinear damping behaviors will greatly influence the vehicle dynamic performance such as the ride comfort and road handling. In this paper, we will theoretically analyze the dynamics of the suspension system with the HESA and give a guide for the HESA design. Then a simulation model of the HESA is built in AMESim to make comparison studies on the different vehicle dynamics caused by the nonlinear damping behaviors of the HESA. The advantages of HESA in terms of ride comfort and road handling will be evaluated in comparison with the similar design without accumulators and the traditional oil shock absorbers.
Data Driven Prognostics With Lack of Training Data Sets
Authors: Xi Zhimin , Zhao Xiangxue
Published: January 2016

Data-driven prognostics typically requires sufficient offline training data sets for accurate remaining useful life (RUL) prediction of engineering products. This paper investigates performances of typical data-driven methodologies when the amount of training data sets is insufficient. The purpose is to better understand these methodologies especially when offline training datasets are insufficient. The neural network, similarity-based approach, and copula-based sampling approach were investigated when only three run-to-failure training units were available. The example of lithium-ion (Li-ion) battery capacity degradation was employed for the demonstration.
An Initial Comparison Between Geographically Distributed and Non-Distributed Student Teams in Design Projects
Authors: Lugo José E. , Miranda Constanza
Published: January 2016

Today, it is common for design engineers around the world to work in distributed teams on a shared project. However, their exposure to shared projects is limited in academia as it poses a series of challenges. This paper explores teams of students working in a design project with its members located in the United States and Chile. During the yearlong study, students tracked their hourly dedication to team tasks while solving a common cross-cultural challenge: designing products to improve mobility in aging populations. To see if team diversity contributed to innovative solutions, teams of students worked in an orchestrated manner, within their regions for a whole academic period. Over a second semester, students from both geographic regions interacted as distributed teams to face the design challenge. Data of the duration and timing of each of the teams design activities and final products were collected. The data were explored to seek similarities and differences between co-located and distributed teams. The effect of distributed teams on product development is discussed, and the challenges and benefits of this practice are explored. Also, recommendations are given for future studies regarding distributed teams.
Heterogeneous Material Design Using a PCA-Based Microstructure Representing Method
Authors: Xu Chao , Gao Shuming , Li Ming
Published: January 2016

A PCA (Principle Component Analysis)-based microstructure descriptor is proposed in this paper. The PCA process is performed on the microstructures of the material database, and is able to maintain the dominant geometric features using a small number of PCA basis. Moreover, this PCA-based descriptor also gives a closed-form expression between the microstructures within the design space and their physical properties. Previous approaches, for example, based on meta-modeling, involve much more expensive off-line finite element computations. Using this novel PCA-based descriptor, an approach to design a microstructure of optimal physical performance is proposed, taking the concrete case of linear elasticity analysis for demonstration.
Design of Miniature Electromagnetic Induction Type MEMS Generators With Multilayer Ceramic Circuit
Authors: Takato Minami , Endo Hiroaki , Yokozeki Yuji , Maezumi Kazuaki , Saito Ken , Uchikoba Fumio
Published: January 2016

This paper discusses the design of a miniature electromagnetic induction type air turbine generator with a multilayer ceramic magnetic circuit. The air turbine is fabricated using a micro electro mechanical systems (MEMS) process, which can form high-accuracy, high-aspect-ratio parts. The magnetic circuit is fabricated using a multilayer ceramic technology that can form a three-dimensional conductor pattern into which a magnetic material can be introduced. By combining these technologies, a miniature generator comprising a miniature magnetic circuit with a helical conductor structure and magnetic core is achieved. In this study, a three-phase and a single-phase generator were fabricated, which produced rotational motion and output waveforms. In this paper, the generators are discussed with respect to the rotational motion and the shape of the magnetic circuit.
Detection of Chiller Energy Efficiency Faults Using Expectation Maximization
Authors: Hu R. Lily , Granderson Jessica , Agogino Alice
Published: January 2016

To detect degradation in energy efficiency of a chiller in a chiller plant, a multivariate Gaussian mixture model is applied. This classification technique was selected to take advantage of an expected correlation between measurable state variables and equipment and operation specifications and system control targets. The hidden variable is the faultiness of the chiller and can take on one of three possible states. The five observed variables correspond to sensor measurements that are typically available and monitored in commercially available chiller plants. The fault detection algorithm is trained on simulated data for the Molecular Foundry at the Lawrence Berkeley National Laboratory and tested on measured sensor data. The results show that detection of severe faults and no faults are relatively accurate, while detection of moderate faults is sometimes mistaken for severe faults. The computation needs are moderate enough for deployment and continuous energy monitoring. Future research outlines the next steps in regards to sensitivity analyses with alternate probability density functions.