bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Stiffness of Tire Calculated From Strain Energy
Authors: Kang Namcheol , Bae Jong-Jin , Suh Jong Beom
Published: January 2016

The vertical stiffness of a tire is the ratio of the vertical force to the deflection; it can be expressed as the summation of the structural stiffness and air stiffness. However, the calculation of the structural stiffness is a challenging topic. This paper presents a new methodology for extracting the structural stiffness from the strain energy of a regular tire. In order to verify our proposed method, the vertical force-deflection results from the finite element method is compared with those from the strain energy method at zero air pressure. Also the results for an inflated tire are compared to calculate the structural stiffness. Finally, we calculated the contribution ratio of the tire components and used an alternative way of extracting the structural stiffness based on changing the Young’s modulus.
Learning Design Through Student-Generated Learning Aids
Authors: Jensen David C. , Beck Dennis
Published: January 2016

In this work we present the results of hands-on design experience implemented in an undergraduate mechanical engineering design course. This work is motivated by the need to provide students with more design-decision making experience to enable them to be ready to engineer upon graduation. Students were guided through the process of designing learning aid prototypes to be used in general engineering education. Three significant results of this work are that: 1) 3D printing was a critical technology for enabling authentic learning environments; 2) Student’s grasp of fundamentals is improved through construction of learning aids compared to their typical classroom use; and 3) Setting limits on resources and client’s time are necessary but require flexibility to enable “learning through failures.” Overall this work demonstrates a structured approach to using additive manufacturing as integrated technology in engineering education.
Underactuated Finger Closing Motion Control Using Dual Drive Actuation
Authors: Boucher Jean-Michel , Birglen Lionel
Published: January 2016

In this paper, a novel technique to prescribe and control the closing motion of a linkage-driven underactuated finger is presented. Since an underactuated, a.k.a self-adaptive, finger generally only has one actuator for a given number of degrees of freedom, its closing motion before making contact with an object is typically imposed by its mechanical design and cannot be changed once the finger is built. In the literature, several closing motions for underactuated fingers have been proposed each one having its own merits and in each case, associated to a particular mechanical layout. In this work, the authors propose a novel design of a partially compliant underactuated finger based on a dual drive actuation system where two motors, which can be used independently or in combination, move the finger. Each of these motors prescribes a different closing motion which has been selected amongst the most commonly found in the literature. In order to characterize the behavior and performances of this finger, a kinetostatic analysis is carried on and a lumped compliance model is developed. The geometry of the finger is then optimized using a genetic algorithm in order to achieve the desired kinematic motions.
A Method for Determining Load-Dependent Stiffness of Flexures
Authors: Merriam Ezekiel G. , Bruton Jared T. , Magleby Spencer P. , Howell Larry L.
Published: January 2016

This paper explores strategies for static balancing of several flexure types. First, it describes a method for determining the load-dependent stiffness behavior of compliant flexures. Load-dependent stiffness means that the stiffness changes when a flexure is subjected to force loads perpendicular to its axis of rotation. A set of non-dimensional parameters is selected to describe the loads and the resulting stiffness. Finite element models of each joint are developed, and stiffness data is gathered for a range of horizontal and vertical loading regimes. The method is verified by comparing results to an analytic model for joints where such is available, and to results in the literature. The load-dependent stiffness behavior is then examined to identify new strategies for static balancing that have not yet appeared in the literature.
Organizing Cells Within Non-Periodic Microarchitectured Materials That Achieve Graded Thermal Expansions
Authors: Hopkins Jonathan B. , Shaw Lucas A. , Weisgraber Todd H. , Farquar George R. , Harvey Christopher D. , Spadaccini Christopher M.
Published: January 2016

The aim of this paper is to introduce an approach for optimally organizing a variety of different unit cell designs within a large lattice such that the bulk behavior of the lattice exhibits a desired Young’s modulus with a graded change in thermal expansion over its geometry. This lattice, called a graded microarchitectured material, can be sandwiched between two other materials with different thermal expansion coefficients to accommodate their different expansions or contractions caused by changing temperature while achieving a desired uniform stiffness. First, this paper provides the theory necessary to calculate the thermal expansion and Young’s modulus of large multi-material lattices that consist of periodic (i.e., repeating) unit cells of the same design. Then it introduces the theory for calculating the graded thermal expansions of a large multimaterial lattice that consists of non-periodic unit cells of different designs. An approach is then provided for optimally designing and organizing different unit cells within a lattice such that both of its ends achieve the same thermal expansion as the two materials between which the lattice is sandwiched. A MATLAB tool is used to generate images of the undeformed and deformed lattices to verify their behavior and various examples are provided as case studies. The theory provided is also verified and validated using finite element analysis and experimentation.
Design Repository and Analogy Computation via Unit Language Analysis (DRACULA) Repository Development
Authors: Lucero Briana , Turner Cameron J. , Linsey Julie
Published: January 2016

Engineering designs are typically constrained by requirements and specifications. The Design Analogy Performance Parameters System (D-APPS) project seeks to provide engineers with a means to transform these product requirements and specifications into functional analogies. D-APPS employs design-by-Analogy (DbA) via critical functionality and the engineering performance parameters from the specifications to produce functional alternative options to design engineers.

Repositories, or databases, provide structured storage of information for retrieval by users in an systemic manner. D-APPS utilizes a repository to store analogy entries, capable of being polled by the developed algorithm. Analogous matches are formulated with the weighting scheme of the algorithm. This research investigates the structures of three alternative repositories, and the current D-APPS database with its interface to the algorithm and design engineer. The architecture of the repository is discussed with example entries and rationale for inclusion.
Polytope Sector-Based Synthesis and Analysis of Microarchitectured Materials With Tunable Thermal Conductivity and Expansion
Authors: Hopkins Jonathan B. , Lee Howon , Fang Nicholas X. , Spadaccini Christopher M.
Published: January 2016

The aim of this paper is to (1) introduce an approach, called Polytope Sector-based Synthesis, for synthesizing 2D or 3D microstructural architectures that exhibit a desired bulk-property directionality (e.g., isotropic, cubic, orthotropic, etc.), and (2) provide general analytical methods that can be used to rapidly optimize the geometric parameters of these architectures such that they achieve a desired combination of bulk thermal conductivity and thermal expansion properties. Although the methods introduced can be applied to general beam-based microstructural architectures, we demonstrate their utility in the context of an architecture that can be tuned to achieve a large range of extreme thermal expansion coefficients — positive, zero, and negative. The material-property-combination region that can be achieved by this architecture is determined within an Ashby-material-property plot of thermal expansion vs. thermal conductivity using the analytical methods introduced. Both 2D and 3D versions of the design have been fabricated using projection microstereolithography.
Static Modeling of a Multi-Segment Serpentine Robotic Tail
Authors: Rone William S. , Ben-Tzvi Pinhas
Published: January 2016

This paper presents a generalized method of determining the static shape conformation of a cable-driven serpentine robot. Given a set of desired cable displacements as model inputs, the model calculates the joint angles and cable tensions that result from those displacements. The model’s governing equations are derived from ensuring static equilibrium at each of the robot’s revolute joints, along with compatibility equations ensuring the joint angles result in the desired cable displacements. Elastic, actuation and gravitational loading are included in the model, and the results analyze the relative impact of each for various combinations of cable displacement inputs. In addition, the impact of elasticity and mass distribution on the accuracy of purely kinematic constant-curvature segment models is presented. In addition, the model also accommodates limits for the serpentine joint angles. The model is implemented in MATLAB, and results are generated to analyze the impact of the actuation, elastic and gravitational effects. Future work will include inertial effects in the model to make it dynamic. These models will be used as the foundation for a serpentine tail design for use on-board a mobile robot, and for task planning to enable that tail to be effectively used in various scenarios.
A Simplified Mathematical Model for Two-Sided Market Systems With an Intervening Engineered Platform
Authors: Sinha Kaushik , Colombo Edoardo F. , Shougarian Narek R. , de Weck Olivier L.
Published: January 2016

A two-sided market involves two different user groups whose interactions are enabled over a platform that provides a distinct set of values to either side. In such market systems, one side’s participation depends on the value created by presence of the other side over the platform. Two-sided market platforms must acquire enough users on both sides in appropriate proportions to generate value to either side of the user market. In this paper, we present a simplified, generic mathematical model for two-sided markets with an intervening platform that enables interaction between the two different sets of users with distinct value propositions. The proposed model captures both the same side as well as cross-side effects (i.e., network externalities) and can capture any behavioral asymmetry between the different sides of the two-sided market system. The cross-side effects are captured using the notion of affinity curves while same side effects are captured using four rate parameters. We demonstrate the methodology on canonical affinity curves and comment on the attainment of stability at the equilibrium points of two-sided market systems. Subsequently a stochastic choice-based model of consumers and developers is described to simulate a two-sided market from grounds-up and the observed affinity curves are documented. Finally we discuss how the two-sided market model links with and impacts the engineering characteristics of the platform.
Dynamic Modeling for a Continuum Robot With Compliant Structure
Authors: Guo Yong , Kang Rongjie , Chen Lisha , Dai Jian
Published: January 2016

Continuum robots have attracted increasing focus in recent years due to their intrinsic compliance and safety. However, the modeling and control of such robots are complex in comparison with conventional rigid ones. This paper presents the design of a pneumatically actuated continuum robot. A 3-dimensional dynamic model is then developed by using the mass-damper-spring system based networks, in which elastic deformation, actuating forces and external forces are taken into account. The model is validated by experiments and shows good agreement with the robotic prototype.
Design and Experimental Evaluation of a Reconfigurable Gravity-Free Muscle Training Assistive Device for Lower-Limb Paralysis Patients
Authors: Tseng Tzu-Yu , Hsu Wei-Chun , Lin Li-Fong , Kuo Chin-Hsing
Published: January 2016

In lower-limb rehabilitation programs, patients that suffer from neuromuscular disorders with manual muscle test (MMT) level 2 are able to perform voluntary muscle contraction and visible limb movement provided that a therapist assists the patient to eliminate the weight of his/her leg. In addition, the physical therapist is clinically needed to guide the patient performing a hip-only or knee-only motion during rehabilitation. The objective of this paper is to present a new assistive training device that replaces the function of the therapist in helping the MMT-level-2 patients self-training their hip and knee flexion/extension motions under an antigravity environment. First, we will present a novel reconfigurable mechanism, which can possess two working configurations for guiding the knee-only and hip-only training, respectively. Then, based on the theory of static balancing, two linear springs are attached to the device to generate an antigravity training environment in both configurations for the patient. The static balance design is verified by a numerical example with the support of software simulation. A prototype is built up and tested on healthy subjects. By using the electromyography (EMG) measurement, the myoelectric signals of four major muscles for the subject with/without the aid of the device are analyzed. The results show that the myoelectric voltages of the stimulated muscles are significantly reduced when the subject is assisted with the device. It further demonstrates that moving the fixation positions of the limb segments to other positions could distinctly reduce the assistive force from the device, which suggests multiple training modes to the patients in strengthening the training intensity. In conclusion, this paper presents a successful pioneering work on the design of rehabilitation devices via the integration of the principles of reconfigurable mechanisms and static balancing.
On a Stiffness Model for Origami Folding
Authors: Nakada Yusuke , Fujieda Yota , Mori Taisei , Iwai Hitoshi , Nakaya Kazumasa , Uehara Ryuhei , Yamabe Masashi
Published: January 2016

An evaluation method for stiffness of origami folding is proposed. As a simple idea to evaluate the stiffness, we may consider a sheet of paper as a rectangular board, and evaluate its elastic deformation. However, when we apply this simple idea to folding of a folded sheet of paper, it contradicts the results of a questionnaire survey. We investigate more details of folding motion of origami, and give a hypothesis that the stiffness of folding motion comes from the intersection points of crease lines, where is the toughest points to fold. Our proposed evaluation method is consistent with the questionnaire survey, and hence useful to evaluate the stiffness of folding.
Combinatorial Method for Characterizing Singular Configurations in Parallel Mechanisms
Authors: Sheffer Avshalom , Shai Offer
Published: January 2016

The paper presents a method for finding the different singular configurations of several types of parallel mechanisms/robots using the combinatorial method. The main topics of the combinatorial method being used are: equimomental line/screw, self-stresses, Dual Kennedy theorem and circle, and various types of 2D and 3D Assur Graphs such as: triad, tetrad and double triad. The paper introduces combinatorial characterization of 3/6 SP and compares it to singularity analysis of 3/6 SP using Grassmann Line Geometry and Grassmann-Cayley Algebra. Finally, the proposed method is applied for characterizing the singular configurations of more complex parallel mechanisms such as 3D tetrad and 3D double-triad.
A Principle of Similarity for Nonlinear Vibration Absorbers
Authors: Habib Giuseppe , Kerschen Gaetan
Published: January 2016

With continual interest in expanding the performance envelope of engineering systems, nonlinear components are increasingly utilized in real-world applications. This causes the failure of well-established techniques to mitigate resonant vibrations. In particular, this holds for the linear tuned vibration absorber (LTVA), which requires an accurate tuning of its natural frequency to the resonant vibration frequency of interest. This is why the nonlinear tuned vibration absorber (NLTVA), the nonlinear counterpart of the LTVA, has been recently developed. An unconventional aspect of this absorber is that its restoring force is tailored according to the nonlinear restoring force of the primary system. This allows the NLTVA to extend the so-called Den Hartog’s equal-peak rule to the nonlinear range.

In this work, a fully analytical procedure, exploiting harmonic balance and perturbation techniques, is developed to define the optimal value of the nonlinear terms of the NLTVA. The developments are such that they can deal with any polynomial nonlinearity in the host structure. Another interesting feature of the NLTVA, discussed in the paper, is that nonlinear terms of different orders do not interact with each other in first approximation, thus they can be treated separately. Numerical results obtained through the shooting method coupled with pseudo-arclength continuation validate the analytical developments.
An Experimental Demonstrator of Semi-Active Tire Damping Enhancement
Authors: Vantsevich Vladimir V. , Judd Gabriel D.
Published: January 2016

Pneumatic tires play a greater role in vibration control of vehicles with stiff or no suspension systems. The challenge is to find an approach that enhances vibratory damping in the tires without increasing the power losses due to rolling resistance effects. This paper presents a novel tire damping enhancement that allows for improved damping within the tire while maintaining the rolling resistance found in a typical pneumatic tire.

The damping enhancement was evaluated by testing an apparatus/demonstrator that simulates a pneumatic tire. The experiment was initially configured to measure the damping ratio of the conventional tire design using a calibrated external excitation and analyzing the decay of the vibration. The damping enhancement presented in the paper was then subjected to the same test and analysis procedure. Results of the analysis show that the proposed damping enhancement measurably decreased the time of the vibratory oscillation.
Design Decision Tradeoffs for Environmental Impact and End of Life Recovery of Cellphones
Authors: Joseph Aaron T. , Schreiner James H. , Thurston Deborah
Published: January 2016

Tradeoff decision making is a difficult problem in design, and even more so when designing for the product lifecycle. Tradeoffs must be made among a broader set of issues, including environmental impact. In addition, normative methods such as utility analysis can become more difficult to implement because of decision modeling issues. This paper presents formal, normative methods for overcoming these difficulties. The method includes a lifecycle analysis which reveals elements of the cellphone design that are most impactful on the environment. A baseline estimate of impacts provides insight into possible redesign options based on minimization of negative environmental impacts. The proposed method also employs a multiattribute utility copula approach, which can be useful when the condition of utility independence is not easily satisfied when formulating a multiattribute utility function. An example using the decision process for end of life (EOL) processing alternatives for cellphones illustrates the method. The extraction of sub-assemblies was determined to be the best decision alternative to recapture value at the disposal stage of the product lifecycle. The copula structure is shown to be effective in analyzing a firm’s tradeoff preferences as well as attribute valuation, providing a straightforward tool for tradeoff decision making.
Exploring the Retention of Sustainable Design Principles in Engineering Practice Through Design Education
Authors: DuPont Bryony , Wisthoff Addison
Published: January 2016

The School of Mechanical, Industrial, and Manufacturing Engineering at Oregon State University is home to one of the largest academic Mechanical Design groups in the country. As a leader in undergraduate design education, we have been able to keep in touch with a large group of mechanical design graduates, and as such are capable of assessing how students retain information learned in undergraduate coursework to see how this understanding is employed in real-world engineering practice. However, the principles governing the design of sustainable products and processes are relatively novel and are only now being integrated into the undergraduate and graduate mechanical design curriculum. It is our hypothesis that particular means of learning and understanding sustainable design — via lectures, homework assignments, design projects, and the use of various sustainability-related LCA tools — will enable the highest retention of sustainable design understanding, and a higher likelihood that this sustainable design knowledge will be propagated into design practice in industry. Multiple curricular studies that explore dissemination and retention of sustainable design skills are being explored, including a junior-level introductory mechanical design course and a graduate level sustainable product development course. In the junior-level course, baseline sustainability knowledge is tested by allowing students to make sustainable design decisions by applying varied skill sets, including general principles, a list of sustainable design guidelines, and an innovative online survey (The GREEn Quiz). The graduate-level course, which employs sustainable design principles within a larger product development architecture, will capitalize on more “expert” knowledge. Future work will also be discussed, including planned validation studies and curriculum improvements, as well as the means of quantifying the retention of sustainable design information.
Cost Optimization of a Solar Humidification-Dehumidification Desalination System Augmented by Thermal Energy Storage
Authors: Abd El-Aziz Khalid M. , Kim Jihun , Hamza Karim , El Morsi Mohamed , Nassef Ashraf O. , Metwalli Sayed M. , Saitou Kazuhiro
Published: January 2016

Solar-powered water desalination is one of the promising approaches for addressing fresh water scarcity in the Middle-East, North Africa, and areas of similar climate around the world. Humidification-dehumidification (HDH) is a scalable, commercially-viable technology that primarily utilizes thermal energy in order to extract fresh water from a high salinity water source. Because of inherent variability and uncertainty in solar energy availability due to daily and seasonal cycles, solar-powered HDH desalination systems may benefit from installing thermal energy storage (TES). TES can allow higher utilization of the installed system components and thus reduce the overall lifecycle cost of fresh water production. This work presents a configuration for a HDH desalination system augmented by TES. The system is optimized using Genetic Algorithms (GA) for minimum total annual cost (TAC) per unit volume of produced potable water while satisfying a preset potable water demand. The optimum results for the same location and cost function are compared with results from a previous system which does not have TES. The comparison shows a considerable reduction in potable water production cost when TES is utilized in addition to the benefit of smaller variation in water production across the day.
Nonsmooth Modal Analysis: Investigation of a 2-DOF Spring-Mass System Subject to an Elastic Impact Law
Authors: Thorin Anders , Legrand Mathias , Junca Stéphane
Published: January 2016

The well-known concept of normal mode for linear systems has been extended to the framework of nonlinear dynamics over the course of the 20th century, initially by Lyapunov, and later by Rosenberg and a growing community of researchers in modal and vibration analysis. This effort has mainly targeted nonlinear smooth systems — the velocity is continuous and differentiable in time — even though systems presenting nonsmooth occurrences have been increasingly studied in the last decades to face the growing industrial need of unilateral contact and friction simulations. Yet, these systems have nearly never been explored from the standpoint of modal analysis.

This contribution addresses the notion of modal analysis of nonsmooth systems. Developments are illustrated on a seemingly simple 2-dof autonomous system, subject to unilateral constraints reflected by a perfectly elastic impact law. Even though friction is ignored, its dynamics appears to be extremely rich. Periodic solutions are sought for given numbers of impacts per period and nonsmooth modes are illustrated for one and two impacts per period in the form of two-dimensional manifolds in the phase space. Also, an unexpected bridge between these modes in the frequency-energy plots is observed.
Modeling Technology Strategies for Thermal Energy Services in Rural Developing Communities
Authors: MacCarty Nordica , Bryden Kenneth (Mark)
Published: January 2016

Approximately 40% of the world’s population lives in energy poverty, lacking basic clean energy to prepare their food, heat water for washing, and provide light in their homes. Access to improved energy services can help to alleviate this poverty and result in significant improvements to health and livelihoods, yet past strategies for meeting the needs of this large and diverse population have often been top-down and focused on single intervention or solution, leading to limited success. Using a systems-based approach to examine residential thermal energy needs, this paper explores five intervention strategies to provide energy services for a remote off-grid village in Mali. The five intervention strategies are (1) general improved biomass cookstoves, (2) advanced biomass cookstoves, (3) communal biomass cookstoves, (4) LPG cookstoves, and (5) solar water heaters. Using a probabilistic multi-objective model that includes technical, environmental, economic, and social objectives, the potential net improvements, critical factors, and sensitivities are investigated. The results show that the factors with the most impact on the outcome of an intervention include the rate of user adoption, value of time, and biomass harvest renewability; in contrast, parameters such as cookstove emission factors have less impact on the outcome. This suggests that the focus of village energy research and development should shift to the design of technologies that have high user adoption rates. That is, the results of this study support the hypothesis that the most effective village energy strategy is one that reinforces the natural user-driven process to move toward efficient and convenient energy services.
Dynamic Performance Analysis of Minimally Actuated 4-Bar Linkages for Upper Limb Rehabilitation
Authors: Xydas Evagoras G. , Mueller Andreas
Published: January 2016

In the last two decades robotic rehabilitation research provided insight regarding the human-robot interaction, helped understand the process by which the impaired nervous system is retrained to better control the hand motion, and led to the development of a number of mathematical and neurophysiological models that describe both the hand motion and the robot control. Now that this pool of knowledge is available, the respective models can be applied in a number of ways outside the robot domain, in which, machines are based on open kinematic chains with n-degrees of freedom (DOF’s) and sophisticated computer control, actuation and sensing. One such example is the use of mechanisms, closed kinematic chains which can still generate complex — yet specific — trajectories with fewer DOF’s. This paper further extends previous work on the design of such passive-active mechanisms that replicate the natural hand motion along a straight-line. The natural hand motion is described by a smooth bell-shaped velocity profile which in turn is generated by the well-established Minimum-Jerk-Model (MJM). Three different straight line 4-bar linkages, a Chebyshev’s, a Hoeken’s and a Watt’s, are examined. First, with the use of kinetostatic analysis and given the natural hand velocity and acceleration, the torque function of non-linear springs that act on the driving link is deduced. Then, given that the springs are acting, interaction with impaired users is considered and the extra actuation power that can maintain the natural velocity profile is calculated. A multibody dynamics software is employed for further assessing the mechanisms’ dynamic response under varying interaction forces. Also, different parameters like inertia are altered and the effects on internal (springs) and external (actuator) power are examined. Then, the three mechanisms are compared with respect to size, required amount of external power, ergonomic issues etc. Finally, it is investigated whether a linear fit of the non-linear spring torque can be adequate for generating the desired MJM trajectory and operate effectively in collaboration with the active part of the control.
On Using Adaptive Surrogate Modeling in Design for Efficient Fluid Power
Authors: Gururaja Rao Lakshmi , Schuh Jonathon , Ewoldt Randy H. , Allison James T.
Published: January 2016

In the last several decades fluid power has been used extensively in diverse industries such as agriculture, construction, marine, offshore resource extraction, and even entertainment. With a vast and ever-increasing spectrum of potential applications, the design of efficient and leak-free components in fluid power systems has become essential. Previous experiments and studies have shown that the use of microtextured surfaces in hydraulic components achieves performance enhancement by reducing friction and leakage. This article aims to build on this recent work through a systematic optimization-based study of performance improvement through microtexture surface design. These studies evaluate the potential of Newtonian fluid properties, coupled with varying surface features, to achieve design objectives for efficiency. This early-stage design strategy aims to find optimal surface features that minimize apparent fluid viscosity (low friction) and the area of the microtexture. The resulting multi-objective optimization (MOO) problem involves a computationally intensive simulation of the system based on computational fluid dynamics (CFD). As a strategy to reduce overall computational expense, this paper describes the development of a new adaptive surrogate modeling strategy for multi-objective optimization. Two case studies are presented: a simple analytical case study illustrating the details of the method and a more sophisticated case study involving the two-dimensional CFD simulation of Newtonian fluids on symmetric surface textures. This design approach embraces the potential of using rheologically complex fluids in engineering system design and optimization. This study can be further extended to a more generalized problem by coupling both fluid and geometrical design decisions.
Tension-Efficient Cable-Driven Robot Design Using Particle Swarm Optimization
Authors: Bryson Joshua T. , Agrawal Sunil K.
Published: January 2016

Cable-driven robots have advantages which make them attractive solutions for a variety of tasks, however, the unidirectional nature of cable actuators complicates the design and often results in multiply redundant cable architectures which increase cost and robot complexity. This paper presents a stochastic optimization approach to the problem of designing a cable routing for a cable-driven manipulator to provide the desired robot workspace while minimizing the cable tensions required to perform a desired task.

Two cable routing design variants are developed for a robot leg through the application of a stochastic optimization methodology called Particle Swarm Optimization. The PSO methodology is summarized, followed by a description of the specific implementation of the methodology to the particular problem of optimizing the cable routing of a robot leg. An objective function is developed to capture all pertinent design criteria in a quantitative evaluation of each particular set of cable parameters. Finally, a description of the PSO execution is presented and the results of the two optimization problems are presented and discussed.
Pseudo-Rigid-Body Models of Compliant DNA Origami Mechanisms
Authors: Zhou Lifeng , Marras Alexander E. , Castro Carlos E. , Su Hai-jun
Published: January 2016

In this paper, we introduce the strategy of designing and analyzing compliant nanomechanisms fabricated with DNA origami which we call compliant DNA origami mechanism (CDOM). The rigid, compliant and flexible parts are constructed by a bunch of double-stranded DNA (dsDNA) helices, fewer dsDNA helices and single-stranded DNA (ssDNA) strands respectively. Just like in macroscopic compliant mechanisms, a CDOM generates its motion via deformation of at least one structural member. During the motion, strain energy is stored and released in the mechanism. These CDOM can suppress thermal fluctuations due to the internal mechanical energy barrier for motion. An example of compliant hinge joint and a bistable four-bar CDOM fabricated with DNA origami are discussed at the end of this paper. The classic pseudo-rigid-body (PRB) model for compliant mechanism is successfully employed to the analysis of these DNA origami nanomechanisms. This PRB model has been used to guide the design of a bistable CDOM for a desired energy landscape.
Design of Control Strategy for a Novel Compliant Flexure-Based Microgripper With Two Jaws
Authors: Wu Zhigang , Li Yangmin
Published: January 2016

This paper proposes a novel compliant flexure-based microgripper with a second order amplifier including Scott-Russell magnification mechanism (SRMM) and lever amplifier. Both the dynamic model of the system and the Bouc-Wen hysteresis model are established and identified through using least square optimization method. For eliminating the hysteresis phenomenon of the actuator, compensation control method based on inverse dynamic model is proposed. A novel control strategy based on adaptive backstepping sliding model control (ABSMC) with compensator is presented to control the nonlinear system. Simulation results demonstrate that the performance of proposed control strategy is superior to conventional backstepping sliding mode control (CBSMC).
Probabilistic Pareto Decision Making Framework for Sustainable Packaging Life Cycle Assessment
Authors: Qi Huihui , Lee Euihark , Gea Hae Chang , Zheng Bin
Published: January 2016

The Packaging industry is one of the largest industries in the world and is associated with many environmental concerns. To reduce its environmental impacts, designing sustainable packaging has been one of the top priorities in packaging industries. A common tools for evaluating the environmental impact of a package design is the Life Cycle Assessment (LCA) which provides information on environmental impacts for different indicators. However, making decisions based on the LCA results leaves us with major challenges. First, the LCA tools should consider various uncertainties such as measurement and data quality. Second, the LCA may give conflicting results on different environmental impact factors. To address these issues, a ranking based decision making framework is proposed in this paper. Within this framework a Probabilistic Pareto Selection method is introduced to select the Pareto Front with uncertainty first. Then, the Ranking based Rate of Substitution is implemented in the decision making process in order to select the best design options based on the trade-off of each Pareto design. Tow case studies are presented to demonstrate the functionality of this framework.
Multi-Objective Evolutionary Algorithms’ Performance in a Support Role
Authors: Woodruff Matthew J. , Simpson Timothy W. , Reed Patrick M.
Published: January 2016

This paper presents a diagnostic assessment study, evaluating five leading multi-objective evolutionary algorithms (MOEAs) on their effectiveness, efficiency, reliability, and controllability on four different formulations of the same benchmark conceptual design problem, using the same underlying model. This assessment entails a broad sampling of the parameter space of each MOEA, for each problem formulation, requiring millions of optimization runs and trillions of model evaluations. The results of this assessment show the strengths and limitations of these MOEAs, establishing the Borg MOEA as a leading algorithm.
Introduction of a Tradeoff Index for Efficient Trade Space Exploration
Authors: Unal Mehmet , Warn Gordon , Simpson Timothy W.
Published: January 2016

The development of many-objective evolutionary algorithms has facilitated solving complex design optimization problems, that is, optimization problems with four or more competing objectives. The outcome of many-objective optimization is often a rich set of solutions, including the non-dominated solutions, with varying degrees of tradeoff amongst the objectives, herein referred to as the trade space. As the number of objectives increases, exploring the trade space and identifying acceptable solutions becomes less straightforward. Visual analytic techniques that transform a high-dimensional trade space into two-dimensional (2D) presentations have been developed to overcome the cognitive challenges associated with exploring high-dimensional trade spaces. Existing visual analytic techniques either identify acceptable solutions using algorithms that do not allow preferences to be formed and applied iteratively, or they rely on exhaustive sets of 2D representations to identify tradeoffs from which acceptable solutions are selected. In this paper, an index is introduced to quantify tradeoffs between any two objectives and integrated into a visual analytic technique. The tradeoff index enables efficient trade space exploration by quickly pinpointing those objectives that have tradeoffs for further exploration, thus reducing the number of 2D representations that must be generated and interpreted while allowing preferences to be formed and applied when selecting a solution. Furthermore, the proposed index is scalable to any number of objectives. Finally, to illustrate the utility of the proposed tradeoff index, a visual analytic technique that is based on this index is applied to a Pareto approximate solution set from a design optimization problem with ten objectives.
Dynamically Consistent Whole-Body Modeling and Simulation Can Reasonably Predict In Vivo Knee Loads
Authors: Adams Matthew J. , Turner Cameron J. , Silverman Anne K.
Published: January 2016

Total knee replacement is a viable treatment for end-stage knee arthritis. With a greater number of younger patients opting for total knee replacement surgery, their increasingly active lifestyles will result in higher wear rates while decreasing the life expectancy of the tibial insert component of the knee replacement implant. In response to the eventuality of patients with more active lifestyles requiring knee replacement surgery, this research proposed to accurately estimate in vivo knee loading over a gait cycle using a dynamically consistent whole-body modeling and simulation method. However, medical treatment based on modeling and simulation must be validated before clinical application becomes feasible.

Estimates for knee loading were compared to publicly-available in vivo knee loading measurements from a telemetric implant [1]. A whole-body musculoskeletal modeling approach was used to simulate the gait cycle of a person who had undergone total knee replacement surgery. This approach was used to calculate net knee joint contact forces. Results suggest that generic whole-body modeling and hybrid forward dynamic simulation techniques for estimating knee joint loads may become clinically feasible in the near future.
Diagnostics and Prognostics of Lithium-Ion Batteries
Authors: Xi Zhimin , Jing Rong , Lee Cheol
Published: January 2016

This paper investigates recent research on battery diagnostics and prognostics especially for Lithium-ion (Li-ion) batteries. Battery diagnostics focuses on battery models and diagnosis algorithms for battery state of charge (SOC) and state of health (SOH) estimation. Battery prognostics elaborates data-driven prognosis algorithms for predicting the remaining useful life (RUL) of battery SOC and SOH. Readers will learn not only basics but also very recent research developments on battery diagnostics and prognostics.
Simulation and Control of a Novel Two-Speed Uninterrupted Mechanical Transmission for Electric Vehicles
Authors: Fang Shengnan , Song Jian , Tai Yuzhuo , Li Fei , Nguyen Truong Sinh
Published: January 2016

Development of electric vehicle (EV) technology leads to the growing performance requirements of driving motor. Introducing a two-speed transmission to EV offers the possibility of economic and dynamic performance improvement of the whole powertrain. This paper presents an innovative two-speed Uninterrupted Mechanical Transmission (UMT), allowing the seamless shifting between two gears. Considering the uncertain factors during gearshift, a robust controller is designed based on H∞ control method. An optimal controller based on linear quadratic regulator is adopted for comparison. The results indicate that the UMT adopting robust controller provides an improvement of dynamic performance and shifting comfort for EV.
A Novel Non-Enzymatic Electrochemical Glucose Biosensor Based on a Simple Lithographic Process
Authors: Hsu Che-Wei , Su Fang-Ci , Peng Po-Yu , Young Hong-Tsu , Yang Mike , Wang Gou-Jen
Published: January 2016

Diabetes is a severe public health problem globally. There are about 387 million people worldwide suffer from this medical condition. Regular detection of a diabetes patient’s blood glucose is essential to maintain the blood sugar level. In this study, a novel non-enzyme glucose biosensor based on a simple lithographic process is proposed. Photoresist AZ-1518 is spinning-coated on a silicon wafer. Exposure and development using a mask with hexagonal close-packed circle array is than conducted to generate a hexagonal close-packed column array of the AZ-1518. The diameter of each circle is set as 4 μm. A thermal melting process is than employed to convert each photoresist column into a photoresist hemisphere. Finally, a gold thin film is then sputtered onto the hemisphere array of AZ-1518 to form the sensing electrode. The sensing area is measured to be enhanced by 8.8 folds. Actual glucose detections demonstrated that the proposed simple non-enzyme glucose biosensor can operate in a linear range of 2.8 mM–27.8 mM and a sensitivity of 18.7 μA mM−1cm−2. A detection limit of 9 μM (S/N = 3) was measured. The proposed novel glucose biosensor possesses advantages of enzyme free, simple fabrication process, low cost, and easy to long-term preservation. It is feasible for future clinical applications.
Managing Functional Coupling Sequences to Reduce Design Complexity During Concept Improvements
Authors: Wang Chu-Yi , Lu Stephen C.-Y. , Liu Ang
Published: January 2016

A large part of design complexity is originated during the concept generation phase when coupling relationships are established between functional requirements and design parameters. Therefore, one of the important tasks in concept improvement is to properly manage the sequence of these functional couplings to minimize the design complexity. This paper introduces a new method, called Design Coupling Sequence (DCS), which, given a design matrix generated during conceptual design, can symmetrically guide the designer through this sequencing task to reduce the design complexity. DCS is developed with sound foundations from logics and mathematics, and useful in engineering practice as real-world design tasks become increasingly complex.
Single-Degree-of-Freedom Rigidly Foldable Origami Flashers
Authors: Lang Robert J. , Magleby Spencer , Howell Larry
Published: January 2016

We present the design for a family of deployable structures based on the origami flasher that are rigidly foldable, i.e., foldable with revolute joints at the hinges and planar rigid faces, and that exhibit a single degree of freedom in their motion. These structures may be used to realize highly compact deployable mechanisms.
Component Lifing Decisions and Maintenance Strategies in the Context of Aeroengine Product-Service Systems Design
Authors: Thomsen Benjamin , Kokkolaras Michael , Månsson Tomas , Isaksson Ola
Published: January 2016

Static structural engine components are typically designed for full lifetime operation. Efforts to reduce weight in order to improve performance result in structural designs associated with higher lifing uncertainty: Maintaining reliability levels may necessitate expensive manufacturing and maintenance solutions. In practice, repair techniques for such structures are available; however, they are not planned for during the design process. The objective of the research presented in this paper is to model and optimize component lifecycle costs with respect to lifing decisions, demonstrated by means of an aeroengine component design example. Both technical (failure) and legislative (certification) implications are considered. The impact of maintenance strategies (repair and/or replace) on lifing design decisions is quantified. It is shown that, under different conditions, it may not be prudent to design for full life but rather accept shorter life and then repair or replace the component. This is especially evident if volumetric effects on low cycle fatigue life are taken into account. It is possible that failure rates based on legacy engines do not translate necessarily to weight-optimized components. Such an analysis can play a significant supporting role in engine component design in a product-service system context.
Bridging the Gaps: Augmenting Design Learning Through Computer-Aided Exploration
Authors: Sriram Anirudh Roshan , Tolbert DeLean , Cardella Monica , Ramani Karthik
Published: January 2016

In helping students learn engineering design, it is very important that they explore complex scenarios that are realistic, and fall outside the domain of standard and over-simplified textbook problems that typically have an answer. A majority of the current educational methods and computer-based tools do not bridge this gap and lack affordances for design exploration. Although computational methods such as Finite Element Analysis have this potential, they are hard to use requiring the users to spend a significant effort. Also, several instructors have identified significant knowledge gaps in concepts related to structural design and strength of materials when the students reach their senior year. To this end, we have developed a problem-based framework to allow for rapid design exploration within engineering design curricula using an easy-to-use, simplified and constrained version of finite elements for stress analysis and exploration. Our framework makes it possible for users to rapidly explore various design options by incorporating a Finite Element Analysis (FEA) backend for design exploration. Our approach uses a constrained design problem for weight minimization that incorporates elements of structural topology optimization but does not automate it. Instead we provide the user the control on decision making for changing the shape through material removal. Using this framework, we explore the decision making of users, and their methodology in the course of the activities that provide a context of control, challenge and reflection. Using video and verbal protocol analysis we integrate assessment in ways that are important and interesting for learning. Our framework demonstrates that the ability of computational tools that are transformed for learning purposes can scaffold and augment learning processes in new ways.