bluuebunny/crossref_metadata_2025 huggingface dataset:
Automotive Glass Exciter Technology for Acoustic Application
Authors: Ebrahimi Babak , Khajepour Amir , Deaville Todd
Published: January 2015

This paper discusses the modeling and analysis of a novel audio subwoofer system for automotive applications using the automobile windshield glass. The use of a piezo-electric actuator coupled with a mechanical amplifier linked to a large glass panel provides a highly efficient method of producing sound. The proposed subwoofer system has the advantage over existing conventional systems of not only reducing the weight of the automobile, but also a significant power savings resulting in an increase of expected fuel economy. Among various design challenges, the glass-sealing design is of huge importance, as it affects the system dynamic response and so the output sound characteristics. The main goal in this manuscript is to evaluate different glass-sealing design configurations by providing a comprehensive Finite Element model of the system. To do so, a comprehensive, yet simplified FE model is developed, and experimental studies are performed in the component level to fine-tune and verify the model. Harmonic response of the system for each sealing configuration design is obtained in the frequency range of 0–200 Hz, and the results are compared and discussed. The finite element model is also beneficial in preliminary design of other components as well as the exciter placement, and predicting the performance of the overall system.
Contextualizing Environmental Sustainability in Design Engineering Curricula
Authors: Ramanujan Devarajan , Bernstein William Z. , Cardella Monica , Ramani Karthik
Published: January 2015

Consideration of environmental sustainability is significantly altering the nature of the mechanical design process. This necessitates integration of sustainability related learning content in design engineering curricula. Although various frameworks for teaching sustainable design exist, a survey conducted among practicing student engineers shows the presence of significant knowledge gaps. To this end, we propose a problem-based framework for contextualizing sustainability assessment within design engineering curricula. Our framework makes it possible for embedding sustainability related concepts within traditional engineering courses and promotes discovery learning among students by means of design exploration. We illustrate our approach using a shape synthesis task that integrates environmental assessment into design by constraining the decision space for domain specific variables. Results from a user survey for analyzing the effects of our framework show its ability to promote both awareness and applicability of sustainable design concepts as well as its potential for use in existing engineering curricula.
Identification of Manufacturability Constraints Through Process Simulation and Data Mining
Authors: Zhou Yuqing , Saitou Kazuhiro
Published: January 2015

With continued demands on high-quality and low-cost products, designers are increasingly required to explore the use of new materials and manufacturing processes. The design for manufacturability rules for unconventional materials and processes will be of great value to improve component manufacturability. Instead of going through years of trial-and-error practice to gain some “rule of thumb” design guidelines, this paper proposed a knowledge-based computational method for manufacturability constraint modeling (MCM) through process simulation, design of experiment, and data mining. With the input of geometric attributes for local critical features of a component, the pre-trained manufacturability constraint model will output the manufacturability prediction and the confidence of the prediction. The 2D visualization of the manufacturability prediction facilitates the interpretation by the human designers, and provides her with concurrent and intuitive manufacturability feedback and directed re-design suggestions. The preliminary result on mild steel stamping process demonstrated the feasibility of the method.
A Kalman Filtering Mechanism Based on Generalized Interval Probability and its Application in Process Variation Estimation
Authors: Hu Jie , Wang Yan , Cheng Aiguo , Zhong Zhihua
Published: January 2015

The Kalman filter has been widely applied for state identification in controllable systems. As a special case of hidden Markov model, it is based on the assumption of linear dependency relationships and Gaussian noises. The classical Kalman filter does not differentiate systematic error from random error associated with observations. In this paper, we propose an extended Kalman filtering mechanism based on generalized interval probability, where systematic error is represented by intervals, state and observable variables are random intervals, and interval-valued Gaussian distributions model the noises. The prediction and update procedures in the new mechanism are derived. A case study of auto-body side frame assembly is used to illustrate the developed mechanism.
Design of Smart Sensing Functions Using Piezoelectric Materials for Failure Diagnostics
Authors: Wang Pingfeng , Wang Zequn , Youn Byeng D. , Lee Soobum
Published: January 2015

This paper presents a robust design framework to develop piezoelectric materials based structural sensing systems for failure diagnostics and prognostics. At first, a detectability measure is proposed to evaluate the performance of any given sensing system given various uncertainties. Thus, the censoring system design problem can be formulated to maximize the detectability of the censoring system through optimally allocating piezoelectric materials into a target structural system. Secondly, the formulated problem can be conveniently solved using reliability-based robust design framework to ensure design robustness while considering the uncertainties. Two engineering case studies are employed to demonstrate the effectiveness of the design framework in developing multifunctional material sensing systems.
Estimation of Reliable Replacement Time of Cutting Tool in Tooling Machines Using the Energy-Based Reliability Model (ERM)
Authors: Lin Po Ting , Chen Kuan-Ting
Published: January 2015

Real-time monitoring systems have been developed for tooling machine for the purpose of investigating the time-dependent cutting conditions, to detect instantaneous events, and to estimate life of cutting tools and the machine itself. An Energy-based Reliability Model (ERM) has been developed for real-time monitoring of cutting conditions. A standardized inspection process was defined and the two most sensible signals, vibrational signals and temperature increments, are collected to monitor the accumulation of dissipated energy during the tooling processes. The ERM then computes the normalized accumulative dissipated energy in replace of evaluating surface quality of workpiece at the end of each tooling process. This paper focuses on the implementation of ERM in the turning process on a lathe. The experimental results showed the dissipated energy linearly grows with respect to the amount of volume removal from the workpiece. The ERM built from the experimental results under the same condition were then utilized to estimate the turning performance under different experimental conditions. As a result, similar trends of dissipated energy versus volume removal were found. Therefore, ERM can be utilized to estimate a reliable replacement time of cutting tool in tooling machines.
Cascaded Predictive Control of Tire Force Saturation Levels for Vehicle Stability
Authors: Sill Justin , Ayalew Beshah
Published: January 2015

This paper proposes and demonstrates a cascaded predictive control strategy that quantifies and uses longitudinal and lateral tire force saturation for directional stability control of road vehicles. Saturation is explicitly defined and computed as the deficiency of a tire to generate a linearly increasing force in either the lateral or longitudinal direction. The optimal management of lateral saturation levels is set as the objective for an upper level controller, while the optimal management of longitudinal saturation among all tires is set as the objective for a lower level driving/braking torque distribution controller. This cascaded predictive scheme exploits prevailing time scale separations between the lateral vehicle dynamics and the tire/wheel dynamics. The performance of the approach is illustrated using simulations of a medium-duty truck undergoing a transient handling maneuver.
Effective Mechanical Properties of Lattice Material Fabricated by Material Extrusion Additive Manufacturing
Authors: Park Sang-In , Rosen David W. , Choi Seung-kyum , Duty Chad E.
Published: January 2015

In this paper, a two-step homogenization method is proposed and implemented for evaluating effective mechanical properties of lattice structured material fabricated by the material extrusion additive manufacturing process. In order to consider the characteristics of the additive manufacturing process in estimation procedures, the levels of scale for homogenization are divided into three stages — the levels of layer deposition, structural element, and lattice structure. The method consists of two transformations among stages. In the first step, the transformation between layer deposition and structural element levels is proposed to find the geometrical and material effective properties of structural elements in the lattice structure. In the second step, the method to estimate effective mechanical properties of lattice material is presented, which uses a unit cell and is based on the discretized homogenization method for periodic structure. The method is implemented for cubic lattice structure and compared to experimental results for validation purposes.
Design for Upstream and Downstream Market Systems With Interoperability Considerations
Authors: Wang Zhichao , Azarm Shapour , Kannan P. K.
Published: January 2015

Product design decision makers are frequently challenged by the difficulty of ensuring compatibility of parts sourced from various suppliers, including the services that the product is designed to integrate. The crux of the difficulty is in analyzing the ability of sourced parts (and services) to interoperate under uncertainty, and the impact of such compatibility on the overall marketing objectives. Therefore, the decisions in a design for market system problem can be closely related to the considerations along both the upstream (e.g., suppliers) and downstream (e.g., service providers and customers) market systems. This paper fills a gap in the existing research by exploring a design decision method that integrates upstream and downstream market systems with interoperability considerations. The proposed method is based on a mathematical model and metric for interoperability presented for the first time in the literature and particularly in the context of engineering design. The design decision framework is demonstrated using three examples: a mechanical design tolerance problem, a power tool design problem, and a tablet computer design problem. The mechanical design problem demonstrates how the interoperability metric can be used as a new way of analyzing tolerances in mechanical systems. The power tool design example involves an integration of upstream and downstream market systems for design selection. The tablet computer design selection problem considers not only the upstream suppliers but also customers and digital service providers along the downstream market system.
Design and Fabrication of Flexible Differential Scanning Nanocalorimeter
Authors: Yin Jiancheng , Yu Shifeng , Wang Shuyu , Lu Ming , Zuo Lei
Published: January 2015

This paper discussed about the design and fabrication process of flexible MEMS based Differential Scanning Calorimeter that greatly enhanced the detection limit and accuracy that allowed for evaluation of molecular interaction. The design utilized polyimide to significantly reduce thermal conduction by hundreds of times than traditional used substrate material. Preliminary fabrication result had successfully demonstrated the polyimide membrane can be firmly adhesive on the wafer during fabrication and easily peeled off from the rigid substrate after the process. Temperature sensing material, VOx was prepared by DC magnetron sputter of sintered vanadium target with O2 flow during the sputtering. Deposition conditions such as the O2 flow rate’s influence on the electrical resistivity and temperature coefficient resistance was investigated. The results fully showed that the material prepared by the method has satisfactory performance to be used as thermistor in the calorimeter. Also, research about thermal analysis of the system further guided and confirmed the feasibility of the design.
Efficient Filtering in Topology Optimization via B-Splines
Authors: Wang Mingming , Qian Xiaoping
Published: January 2015

This paper presents a B-spline based approach for topology optimization of three-dimensional (3D) problems where the density representation is based on B-splines. Compared with the usual density filter in topology optimization, the new B-spline based density representation approach is advantageous in both memory usage and CPU time. This is achieved through the use of tensor-product form of B-splines. As such, the storage of the filtered density variables is linear with respect to the effective filter size instead of the cubic order as in the usual density filter. Numerical examples of 3D topology optimization of minimal compliance and heat conduction problems are demonstrated. We further reveal that our B-spline based density representation resolves the bottleneck challenge in multiple density per element optimization scheme where the storage of filtering weights had been prohibitively expensive.
Neural Mechanisms of Evaluation and Memory of Product
Authors: Ueda Kazutaka
Published: January 2015

A consumer’s emotional response to a product is influenced by cognitive processes, such as memories associated with use of the product and expectations of its performance. Here, we propose a cognitive neural model of Expectology, called PEAM (Prediction - Experience - Appraisal - Memory), as a novel tool that considers consumers’ emotional responses in order to aid in product design. The PEAM model divides cognitive processes associated with product use into 4 phases: prediction, experience, appraisal, and memory. We examined the spatiotemporal changes in brain activity associated with product evaluation and memory during the prediction phase, by obtaining electroencephalograms (EEGs). EEGs of 10 healthy participants with normal or corrected-to-normal vision were recorded while they viewed images of products as well as when they provided a preference rating for each product. Our results revealed significantly increased neural activity in the gamma frequency in the temporal areas, the brain regions where declarative memory is stored, and in the prefrontal area for products that were rated as preferable. Our data suggest that memory is used for product evaluation in the prediction phase. These findings also suggest that activity in these specific brain areas are reliable predictors for product evaluation.
Geometric Design of a Bio-Inspired Flapping Wing Mechanism Based on Bennett-Derived 6R Deployable Mechanisms
Authors: Hailin Huang , Bing Li
Published: January 2015

In this paper, we present the concept of designing flapping wing air vehicle by using the deployable mechanisms. A novel deployable 6R mechanism, with the deploying/folding motion of which similar to the flapping motion of the vehicle, is first designed by adding two revolute joints in the adjacent two links of the deployable Bennett linkage. The mobility of this mechanism is analyzed based on a coplanar 2-twist screw system. An intuitive projective approach for the geometric design of the 6R deployable mechanism is proposed by projecting the joint axes on the deployed plane. Then the geometric parameters of the deployable mechanism can be determined. By using another 4R deployable Bennett connector, the two 6R deployable wing mechanisms can be connected together such that the whole flapping wing mechanism has a single degree of freedom (DOF).
Autonomous Loitering Control for a Flapping Wing Miniature Aerial Vehicle With Independent Wing Control
Authors: Roberts Luke , Bruck Hugh A. , Gupta Satyandra K.
Published: January 2015

Flapping wing miniature aerial vehicles (FWMAVs) offer advantages over traditional fixed wing or quadrotor MAV platforms because they are more maneuverable than fixed wing aircraft and are more energy efficient than quadrotors, while being quieter than both. Currently, autonomy in FWMAVs has only been implemented in flapping vehicles without independent wing control, limiting their level of control. We have developed Robo Raven IV, a FWMAV platform with independently controllable wings and an actuated tail controlled by an onboard autopilot system. In this paper, we present the details of Robo Raven IV platform along with a control algorithm that uses a GPS, gyroscope, compass, and custom PID controller to autonomously loiter about a predefined point. We show through simulation that this system has the ability to loiter in a 50 meter radius around a predefined location through the manipulation of the wings and tail. A simulation of the algorithm using characterized GPS and tail response error via a PID controller is also developed. Flight testing of Robo Raven IV demonstrated the success of this platform, even in winds of up to 10 mph.
Robust Design on KANSEI of Product Satisfying Emotion and Preference of Target Customers Using Taguchi Method
Authors: Aoyama Hideki , Kawamura Yuka , Oya Tetsuo
Published: January 2015

It has been difficult to make product differentiations from standpoints on function and quality because each manufacturer has had the same level of manufacturing technologies. In order to provide attractive products for customers, it is essential to product emotional products satisfying a specified target level of KANSEI and preference of restricted customers. Taguchi method is effective for robust design of product functions but it is uncertain for design of product forms. In this paper, Taguchi method is applied for robust form design satisfying a specified KANSEI and preference of restricted customers by proposing and introducing the original S/N ratio. The effectiveness of the proposed form design method is verified by experiments based on questionnaires.
Effect of Varying the Number of Rollers on Dynamics of a Cylindrical Roller Bearing
Authors: Sharma Aditya , Amarnath M. , Kankar P. K.
Published: January 2015

In present paper, nonlinear dynamic model has been developed for cylindrical roller bearings. The Hertzian contact theory is used to derive a two degree of freedom model which considers nonlinearity due to clearance. The nonlinear dynamic behaviour of cylindrical roller bearing has been studied with varying number of rollers supporting load. The modified Newmark-β numerical integration technique has been used to solve the equations of motion. All the results are presented in the form of Fast Fourier Transforms and Poincarè maps. As the number of rollers is increases, system becomes stiffer. The results show that the number of rollers supporting load is one of the important parameters affecting the dynamics of rotor bearing system. Therefore, it must be considered at the design stage to understand the dynamic characteristics and stability of the rotor bearing system.
Quasi-Static Impact Response of Single-Curved Foldcore Sandwich Shells
Authors: Gattas Joseph M. , You Zhong
Published: January 2015

Honeycomb core sandwich shells are used for many applications, but available unit architectures and global curvatures are limited. Numerous origami-core sandwich shells, known as foldcores, have been proposed as alternatives, but studies into their mechanical performance are few. This paper conducts a preliminary investigation into the impact resistance and energy absorption of single-curved foldcore sandwich shells that utilise Miura-derivative patterns as their core geometry. A numerical analysis on three Miura-derivative core patterns, the Arc-Miura (AM), Non-Developable Miura (ND), and Non-Flat Foldable Miura (NF) patterns, shows that ND and AM-type shells have similar impact resistance to each other, and superior impact resistance to NF-type shells. Prototypes of aluminium ND and AM-type foldcores are constructed and used to validate numerical models. Numerical models were then used to draw comparisons with an over-expanded honeycomb (OX-core) sandwich shell. It was seen that the OX-core had a better energy absorption capacity than either of the foldcores. However the AM-type foldcore possessed superior initial strength, and the ND-type possessed superior response uniformity, attributes that might be exploitable with future research. A brief parametric study on ND-type shells suggested that in general, for a given design radius and density, a foldcore shell configuration with a lower unit cell area-to-height ratio will have a higher energy absorption capability.
Tree-Like Resonators Assembly for Broadband Energy Harvesting
Authors: Kubota Madoka , Flynn Morris , Hikihara Takashi , Putkaradze Vakhtang
Published: January 2015

This paper specifies the configuration of a harvester for absorbing energy from ambient oscillation with broadband frequencies. Two major methodologies for broadband harvesting have been developed, one is the use of a nonlinear oscillator, and the other is the use of multiple resonators. We focus on the traditional way of assembling multiple resonators but suggest some nontrivial improvements in the configuration. In order to make a variety of resonant frequencies, resonators can be connected in series, in the form of a tree-like structure. The energy absorption of the tree configuration harvester under broadband frequency excitation is tested, and additionally the placement of multiple resonators is also considered. The numerical results indicate that our proposal of the tree configuration might be useful under broadband frequency excitation.
Modeling Information Gathering Decisions in Systems Engineering Projects
Authors: Hsiao Chuck , Malak Richard
Published: January 2015

Decisions in systems engineering projects commonly are made under significant amounts of uncertainty. This uncertainty can exist in many areas such as the performance of subsystems, interactions between subsystems, or project resource requirements such as budget or personnel. System engineers often can choose to gather information that reduces uncertainty, which allows for potentially better decisions, but at the cost of resources expended in acquiring the information. However, our understanding of how to analyze situations involving gathering information is limited, and thus heuristics, intuition, or deadlines are often used to judge the amount of information gathering needed in a decision. System engineers would benefit from a better understanding of how to determine the amount of information gathering needed to support a decision.

This paper introduces Partially Observable Markov Decision Processes (POMDPs) as a formalism for modeling information-gathering decisions in systems engineering. A POMDP can model different states, alternatives, outcomes, and probabilities of outcomes to represent a decision maker’s beliefs about his situation. It also can represent sequential decisions in a compact format, avoiding the combinatorial explosion of decision trees and similar representations. The solution of a POMDP, in the form of value functions, prescribes the best course of action based on a decision maker’s beliefs about his situation. The value functions also determine if more information gathering is needed. Sophisticated computational solvers for POMDPs have been developed in recent years, allowing for a straightforward analysis of different alternatives, and determining the optimal course of action in a given situation. This paper demonstrates using a POMDP to model a systems engineering problem, and compares this approach with other approaches that account for information gathering in decision making.
A Bayesian Framework of Computing and Updating Wavelet Parameter Distributions for Identifying Early Bearing Faults
Authors: Tse Peter W. , Wang Dong
Published: January 2015

Rolling element bearings are widely used in machines to support rotation shafts. Bearing failures may result in machine breakdown. In order to prevent bearing failures, early bearing faults are required to be identified. Wavelet analysis has proven to be an effective method for extracting early bearing fault features. Proper selection of wavelet parameters is crucial to wavelet analysis. In this paper, a Bayesian framework is proposed to compute and update wavelet parameter distributions. First, a smoothness index is used as the objective function because it has specific upper and lower bounds. Second, a general sequential Monte Carlo method is introduced to analytically derive the joint posterior probability density function of wavelet parameters. Last, approximately optimal wavelet parameters are inferred from the joint posterior probability density function. Simulated and real case studies are investigated to demonstrate that the proposed framework is effective in extracting early bearing fault features.
Detailed Modeling of Wind Turbine Gear Set by General-Purpose Multibody Dynamics
Authors: Okabe Eduardo Paiva , Masarati Pierangelo
Published: January 2015

This work presents the development of a kinematic model of a spur gear pair and the implementation of a hydrodynamic bearing in a multidisciplinary multibody dynamics software. Both models are employed to simulate the behavior of a planetary gear set typically adopted in wind turbines. Geared transmissions have been a popular choice to transmit the rotation of the main rotor to the electrical generator in this type of turbine. Compared to other kinds of transmission, a gearbox is more compact, robust and require low maintenance over its lifetime, which is interesting, since these turbines are usually installed in remote places. The gearbox of a wind turbine is normally composed by a set of spur gears and bearings, assembled in arrangement known as epicyclic. Spur gears generally have an involute profile, which allows a constant transmission of the angular speed. This kinematic constraint between gears is defined by the angle that the surface of their teeth is in contact with. This angle is known as pressure angle and, by design, it should remain constant during operation. However, a variation of the distance between gears changes this angle, which also changes the direction of the transmission of the movement. To account for this effect, the joint is described by the projection of the absolute velocity of the contact point of each gear on the line of action, which is calculated from their position. Another important group of elements are the bearings that support gear and shafts. They can absorb part of the vibration, and compensate misalignments and teeth surface failures. Hydrodynamic bearings are widely employed in turbomachinery, due to their simplicity, long life and good damping properties, which are features that wind turbines can benefit from. Most of the hydrodynamic bearing models are two dimensional, so they have to be adapted to be implemented in a multibody dynamics software. The development of these modifications is also described in this work, so any other hydrodynamic bearing model can be easily adapted using the same procedure. Finally, a model of the wind turbine gearbox is presented, and some of the features of using the aforementioned elements inside a multibody dynamics software can be highlighted.
Simple and Accurate Analytical Solutions of the Electrostatically Actuated Curled Beam Problem
Authors: Younis Mohammad I.
Published: January 2015

We present analytical solutions of the electrostatically actuated initially deformed cantilever beam problem. We use a continuous Euler-Bernoulli beam model combined with a single-mode Galerkin approximation. We derive simple analytical expressions for two commonly observed deformed beams configurations: the curled and tilted configurations. The derived analytical formulas are validated by comparing their results to experimental data in the literature and numerical results of a multi-mode reduced order model. The derived expressions do not involve any complicated integrals or complex terms and can be conveniently used by designers for quick, yet accurate, estimations. The formulas are found to yield accurate results for most commonly encountered microbeams of initial tip deflections of few microns. For largely deformed beams, we found that these formulas yield less accurate results due to the limitations of the single-mode approximations they are based on. In such cases, multi-mode reduced order models need to be utilized.
Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode
Authors: Masri Karim M. , Younis Mohammad I.
Published: January 2015

We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.
Least Levels Disassembly Graph Method for Selective Disassembly Planning
Authors: Wang Chenggang , Mitrouchev Peter , Li Guiqin , Lu Lixin
Published: January 2015

As known, the number of possible disassembly sequences increases significantly with the number of parts in a product. For selective disassembly, for instance, it is important to eliminate the components unrelated with the target component prior to sequence generation. In order to address this configuration, a method for disassembly sequences generation in the case of selective disassembly is presented in this paper. Based on the least levels of disassembly product graph it allows reducing computation resources. Instead of considering the geometric constrains for each pair of components, the proposed method considers the geometric contact and collision relationships among the components in order to generate the disassembly graph for sequences planning. The method is applied for automatically generating the selective disassembly sequences thus allowing reducing the computation resources and is illustrated through an example.
Design and Analysis of a Sustainable Multi-Objective Distribution Network Using Simulation-Based Optimisation
Authors: Rees Morgan , Wang Qing
Published: January 2015

This paper examines the distribution network for a manufacturing business looking at aspects of sustainability including economic, environmental and social considerations. The problem is initially approached mathematically, then applied experimentally using a specialist software, Orion-pi. A real life business, Rettig ICC, is used as a case study to show how the theory could be applied to a practical example and would provide financial savings, reduced carbon emissions and lay the groundwork for a more ethical business strategy. The results show it will be a financially and environmentally positive move to decrease the current activity at Birtley and operate an additional smaller distribution centre at Coventry.
ViSER: Visualizing Supply Chains for Eco-Conscious Redesign
Authors: Bernstein William Z. , Ramanujan Devarajan , Elmqvist Niklas , Zhao Fu , Ramani Karthik
Published: January 2015

In this paper, we present ViSER, an interactive visual analytics platform that visualizes supply chain data for enabling eco-conscious redesign. ViSER provides a visualization dashboard consisting of multiple mutually coordinated views that provide different perspectives on a particular supply chain scenario. Our platform allows users to visualize a change propagation metric associated with a particular redesign path. Hence, the user can balance the advantages of a redesign opportunity with the risk associated with its effect on the rest of the supply chain. Furthermore, ViSER offers lifecycle data representations that inform users’ decisions particularly in the context of eco-conscious re-design. Coupling such environmental data with graph-based visualizations of product architecture, ViSER provides a novel decision platform for designers with a range of expertise levels. To demonstrate its utility, two use-case scenarios, from both a novice and expert perspective, are presented in detail.
Identifying and Mapping Excess Relationships in Complex Engineered Systems
Authors: Cansler Ethan Z. , Ferguson Scott M. , Mattson Christopher A.
Published: January 2015

The design of complex engineered systems is one of the great challenges currently facing designers. Beyond addressing the obvious difficulties stemming from system complexity, designers must also consider that such systems will likely evolve within their service lifetime. As future environments are often unknown, designers must create systems capable of evolving in-service to meet unforeseen requirements. Previous research exploring the concept of service-phase evolvability has indicated that design excess is a critical factor enabling such change. This paper explores how information available from current techniques in the design literature that focus on system change can be expanded and synthesized to map excess within a component and within a system. Examples are presented where information from High-Definition Design Structure Matrices and functional models are used to complete this mapping. The goal of this paper is to serve as the foundation for quantifying design excess in future work.
A Review of Signal Processing Techniques for Continuous-Scan Laser Doppler Vibrometry
Authors: Yang Shifei , Ehrhardt David , Allen Matthew S.
Published: January 2015

A Laser Doppler Vibrometer (LDV) measures the laser Doppler frequency shift and converts it to the velocity at a point of a structure along the laser beam direction. In commercially available scanning LDV, the laser is redirected by a pair of orthogonal mirrors from one point to another, measuring the responses at these points sequentially. Continuous-Scan Laser Doppler Vibrometry (CSLDV) is built on scanning LDV; the laser sweeps continuously over a structure while recording the response along the laser path. The continuous-scan approach can greatly accelerate modal testing, providing spatially detailed vibration shape of the structure at tens or even hundreds of points in the time that is required to measure the vibration at a single point. However, extracting vibration shapes from CSLDV measurements is challenging because the laser spot is continuously moving. This technical difficulty and the equipment cost have become the major barriers that prevent the widespread use of CSLDV. Several algorithms to extract vibration shapes have been developed since CSLDV was introduced. Ewins et al proposed a polynomial approach that treats the vibration shape along the laser scan path as a polynomial function of the laser position. The polynomial coefficients were found from the sideband harmonics in the frequency spectrum of the acquired velocity signal. Allen et al proposed a lifting approach that collects the measured responses at the same location along the laser path. The reorganized measurements appear to be from a set of pseudo transducers attached to the structure. Hence, the well-established conventional modal identification routines can be applied to process CSLDV measurement. Algorithms based on linear time periodic system identification theory were explored as well. These algorithms are based on the fact that the measured velocities along the laser path are the responses of a special liner time periodic system when a closed, periodic laser scan pattern is employed. For the first time, this work compares these signal processing techniques employed in different applications using the same set of data obtained from a cantilever beam. The noise and uncertainty in the reconstructed vibration shapes are discussed in order to present the advantages and disadvantages of each method.
Performance of a Lotka-Volterra System for Representing Biofouling Processes
Authors: Komninelli Foteini , Iliopoulos Athanasios , Michopoulos John G.
Published: January 2015

In order to assess the feasibility and performance of a minimal multiphysics model for representing the spatiotemporal evolution of biofouling process, we selected the coupled diffusive generalization of the Lotka-Volterra PDEs to govern the spatiotemporal evolution of population densities of predator-prey colonies in a computational domain. The implementation of the finite element solution of the system was performed and the associated numerical solution of the system was achieved. An analysis was performed that highlights certain choices of the control parameters of the model and their effect on the spatiotemporal behavior of the system. Potential extensions of the model are presented to incorporate an agent that inhibits antibiofouling and study its effect. An evaluation of the features of the model are concluding the paper.
Bistable Compliant Mechanism Using Magneto Active Elastomer Actuation
Authors: Crivaro Adrienne , Sheridan Rob , Frecker Mary , Simpson Timothy W. , von Lockette Paris
Published: January 2015

In the emerging field of origami engineering, it is important to investigate ways to achieve large deformations to enable significant shape transformations. One way to achieve this is through the use of bistable mechanisms. The goal in this research is to investigate the feasibility and design of a compliant bistable mechanism that is actuated by magneto active elastomer (MAE) material. The MAE material has magnetic particles embedded in the material that are aligned during the curing process. When exposed to an external field, the material deforms to align the embedded particles with the field. We investigate actuation of the MAE material through the development of finite element analysis (FEA) models to predict the magnetic field required to snap the device from its first stable position to its second for various geometries and field strengths. The FEA model also predicts the displacement of the center of the mechanism as it moves from one position to the other to determine if the device is in fact bistable. These results help show the relationship between the substrate properties and the bistability of the device. Experimental results validate the FEA models and demonstrate the functionality of active materials to be used as actuators for such devices and applications of origami engineering.
State of Charge Estimation of Lithium-Ion Batteries Considering Model Bias and Parameter Uncertainties
Authors: Xi Zhimin , Jing Rong , Yang Xiaoguang , Decker Ed
Published: January 2015

Up to date, model and parameter uncertainties are generally overlooked by majority of researchers in the field of battery study. As a consequence, accuracy of the SOC estimation is dominated by the model fidelity and may vary from cell-to-cell. This paper proposes a systematic framework with associated methodologies to quantify the battery model and parameter uncertainties for more effective battery SOC estimation. Such a framework is also generally applicable for estimating other battery performances of interest (e.g. capacity and power capability). There are two major benefits using the proposed framework: i) consideration of the cell-to-cell variability, and ii) accuracy improvement of the low fidelity model comparable to the high fidelity without scarifying computational efficiency. One case study is used to demonstrate the effectiveness of the proposed framework.
Modeling of Uncertainties in Bladed Disks Using a Nonparametric Approach
Authors: Nyssen Florence , Arnst Maarten , Golinval Jean-Claude
Published: January 2015

In the field of turbomachinery, the assumption of cyclic symmetry of the different rotor stages is usually made to reduce the required computational resources. However, in reality small random blade-to-blade variations, known as mistuning, appear due to manufacturing tolerances, wear during use, etc. and disturb the dynamic behavior of bladed disks. This work proposes a new combination of two modeling techniques, incorporating the advantages of both methods to model more precisely the mistuned response of bladed disks with reduced computational time. In particular, we combine the reduced-order modeling technique based on cyclic symmetry with the nonparametric approach for modeling uncertainties in order to introduce them directly in the modal space of the blades of the structure and thus reduce the size of the model. We perform a numerical comparison between the frequency response function of a bladed structure. The proposed method allows to retrieve the results of the nonparametric approach while reducing the size of the structural matrices.
Real-Time Safe Navigation in Crowded Dynamic Environments Using Generalized Velocity Obstacles
Authors: Mahmoodi Mostafa , Alipour Khalil , Masouleh Mehdi Tale , Mohammadi Hadi Beik
Published: January 2015

This paper aims at developing a real-time, robust, and reliable navigation method for an omnidirectional robot, the so-called MRL-SSL RoboCup robot, can be used in crowded dynamically-changing environments. To this end, a local motion planner will be introduced which combining the Generalized Velocity Obstacles (GVO) notion and a heuristic approach for determining the time horizon such that the inevitable collision states can successfully be avoided. The proposed method considers not only the kinematics of the robot but also its dynamics. Moreover, it could be extended to a wide range of practical path planning problems containing uncertainties. Finally, in order to demonstrate the performance and effectiveness of the proposed motion planner for the omnimobile robots, some practical scenarios are simulated.
Energy Efficiency of Industrial Systems: A Design Research Perspective
Authors: Farel Romain , Bekhradi Alborz
Published: January 2015

Beyond the usual energy efficiency of buildings, industrial energy efficiency involves major politico-economical and environmental challenges, among which the emergence of eco-industrial parks and symbioses. Solving these challenges require reliable methodologies and tools. Having interviewed some major industrial energy stakeholders, it appeared that despite of their motivation, energy efficiency projects were not really successful because of the difficulty in identifying adequate simulation methodologies and/or tools. Moreover, in spite of multiple research projects in industrial energy efficiency, it seems that previous research works do not sufficiently support a systematic and integration view.

In this paper, we propose a critical review and a categorization of energy efficiency research methodologies and tools. The analysis of these solutions results in the building of an inventory of more than 50 modeling and simulation software tools. Furthermore, a positing matrix is designed in order to map energy efficiency solutions according to identified granularity levels of industrial systems as well as their marketing maturity level.
Time-Dependent Reliability Analysis Using the Total Probability Theorem
Authors: Mourelatos Zissimos P. , Majcher Monica , Pandey Vijitashwa , Baseski Igor
Published: January 2015

A new reliability analysis method is proposed for time-dependent problems with limit-state functions of input random variables, input random processes and explicit in time using the total probability theorem and the concept of composite limit state. The input random processes are assumed Gaussian. They are expressed in terms of standard normal variables using a spectral decomposition method. The total probability theorem is employed to calculate the time-dependent probability of failure using a time-dependent conditional probability which is computed accurately and efficiently in the standard normal space using FORM and a composite limit state of linear instantaneous limit states. If the dimensionality of the total probability theorem integral (equal to the number of input random variables) is small, we can easily calculate it using Gauss quadrature numerical integration. Otherwise, simple Monte Carlo simulation or adaptive importance sampling is used based on a pre-built Kriging metamodel of the conditional probability. An example from the literature on the design of a hydrokinetic turbine blade under time-dependent river flow load demonstrates all developments.
A Semantic Framework to Integrate Healthcare and Clinical Knowledge in Medical Device Innovation and Design
Authors: Hagedorn Thomas J. , Grosse Ian R. , Krishnamurty Sundar , Wileden Jack C.
Published: January 2015

Within the medical field, there has been significant progress in the development of ontologies and their subsequent use to represent and utilize knowledge more effectively. These have culminated in the creation of large, curated medical ontologies for use in a wide array of applications, as well as higher level frameworks to organize and mitigate conflicts between disparate ontologies. While the engineering field has not been a similar progress in developing and adopting curated ontologies, there has been extensive research into how to effectively use semantic frameworks in engineering knowledge management and design in general, and specifically for the effective creation and documentation of functional basis models. Functional models are a useful tool in the early phases of product design, as they can help more effectively define goals and represent how a product must behave to accomplish these goals. In the specific realm of medical device design however, this process is complicated by a number of factors, including the complexity of the healthcare system and clinical knowledge, as well as a lack of domain specific expertise in the engineering field. Because of these challenges, effective transfer of information from medical domain experts to an engineering context and subsequent utilization of this information are essential to the success of a medical device innovation project. Despite the magnitude and importance of this challenge, few tools exist to help designers record, contextualize, and utilize medical knowledge for the specific purpose of engineering design. In this paper, we present a framework for directly integrating clinical knowledge relating to medical science and practice into the early phases of the engineering process to assist in medical device innovation and design. To accomplish this, existing medical and engineering ontologies were researched, obtained, and interlinked so as to explicitly tie functional models of medical device designs to the underlying medical clinical knowledge and procedures that define a product’s operational environment. The result is a framework that unifies the knowledge embodied in large medical ontologies with the functional basis ontology. This integration facilitates the effective preservation and use of medical knowledge in functional model creation and in the engineering design innovation process in general. To demonstrate the potential usefulness of this framework, we present a simple example of how our framework can be used to associate a functional model with a deconstructed medical procedure, thus enabling the seamless integration of a medical perspective directly into an engineering model.