bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Mode Q Control in Multifrequency Atomic Force Microscopy
Authors: Ruppert Michael G. , Moheimani S. O. Reza
Published: January 2016

Various Atomic Force Microscopy (AFM) modes have emerged which rely on the excitation and detection of multiple eigenmodes of the microcantilever. The conventional control loops employed in multifrequency AFM (MF-AFM) such as bimodal imaging where the fundamental mode is used to map the topography and a higher eigenmode is used to map sample material properties only focus on maintaining low bandwidth signals such as amplitude and/or frequency shift. However, the ability to perform additional high bandwidth control of the quality (Q) factor of the participating modes is believed to be imperative to unfolding the full potential of these methods. This can be achieved by employing a multi-mode Q control approach utilizing positive position feedback. The controller exhibits remarkable performance in arbitrarily modifying the Q factor of multiple eigenmodes as well as guaranteed stability properties when used on flexible structures with collocated actuators and sensors. A controller design method based on pole placement optimization is proposed for setting an arbitrary on-resonance Q factor of the participating eigenmodes. Experimental results using bimodal AFM imaging on a two component polymer sample are presented.
Resilience Analysis and Allocation for Complex Systems Using Bayesian Network
Authors: Yodo Nita , Wang Pingfeng
Published: January 2016

The concept of resilience has been explored in diverse disciplines. However, there are only a few which focus on how to quantitatively measure engineering resilience and allocate resilience in engineering system design. This paper is dedicated to exploring the gap between quantitative and qualitative assessments of engineering resilience in the domain of designing complex engineered systems, thus optimally allocating resilience into subsystems and components level in industrial applications. A conceptual framework is first proposed for modeling engineering resilience, and then Bayesian Network is employed as a quantitative tool for the assessment and analysis of engineering resilience for complex systems. One industrial-based case study, a supply chain system, is employed to demonstrate the proposed approach. The proposed resilience quantification and allocation approach using Bayesian Networks would empower system designers to have a better grasp of the weakness and strength of their own systems against system disruptions induced by adverse failure events.
Reliability Analysis and Design Considering Disjointed Active Failure Regions
Authors: Wang Pingfeng , Cui Xiaolong , Wang Zequn
Published: January 2016

Failure of practical engineering systems could be induced by several correlated failure modes, and consequently reliability analysis are conducted with multiple disjointed failure regions in the system random input space. Problems with disjointed failure regions create a great challenge for existing reliability analysis approaches due to the discontinuity of the system performance function between these regions. This paper presents a new enhanced Monte Carlo simulation (EMCS) approach for reliability analysis and design considering disjointed failure regions. The ordinary Kriging method is adopted to construct surrogate model for the performance function so that Monte Carlo simulation (MCS) can be used to estimate the reliability. A maximum failure potential based sampling scheme is developed to iteratively search failure samples and update the Kriging model. Two case studies are used to demonstrate the efficacy of the proposed methodology.
Application of Hub-Wheel Electric Motor Integrated With Two Step Planetary Transmission for Heavy Off-Road Vehicles
Authors: Tehrani Mohammad Gerami , Montonen Juho , Immonen Paula , Sinkko Simo , Kaikko Esa-Pekka , Nokka Jarkko , Sopanen Jussi , Pyrhönen Juha
Published: January 2016

An integrated electro-mechanical drive train component for heavy duty vehicles in off-road applications is presented. The component utilizes a two-step transmission and a tooth-coil permanent magnet motor and has compact size enabling in-wheel installation. The driveline design procedure is surveyed to explore the advantages of a geared electric motor in electric drivelines. Multibody dynamic simulation is applied to verify the functionality of the driveline. A vehicle generic model that is compatible with a multibody simulator program is developed to describe the performance of the proposed driveline in different vehicles. A co-simulation procedure is applied to combine the electric motor and vehicle body simulation models. It is shown that the co-simulation can be performed in real-time, thus enabling a human driver to control the vehicle. A comparison is made of the rear wheel drive and wheel mounted electric motor from the efficiency and performance points of view. The power consumption of vehicles with different driveline architectures is calculated to diagnose the weak points of the system and enhancement solutions are proposed.
Gravity Balancing of a Spatial Articulated Manipulator Based on a New Spring Mechanism
Authors: Shieh Win-Bin , Chou Ben-Shiou
Published: January 2016

Based on the theory of conservation of potential energy, design of a gravity-balancing spatial articulated manipulator by the use of a proposed spring mechanism is presented. Since the gravitational potential energy of the mass system of a spatial articulated manipulator of n links depends only on the orientation of each link within the system, the entire manipulator can then be considered to be equivalent to an array of n degenerated ground-adjacent links in the aspect of the potential energy. Moreover, since the gravitational potential energy of a rotary link moving in a vertical plane is a trigonometric function and the Scotch york mechanism is also a well-known harmonic motion generator, a new spring mechanism composed of a Scotch york, a compression spring, and a gear pair is used to balance the gravitational potential energy of each degenerated link. With a built-in spring mechanism embedded on each joint of the articulated manipulator, the entire spatial articulated manipulator maintains can be in equilibrium at all configurations, which is verified by the simulation of the system modeled in a commercial software Pro-Engineer. The prototyping of a practical system will be implemented in the near future.
The Effect of Non-Symmetric FRF on Machining: A Case Study
Authors: Hajdu David , Insperger Tamas , Stepan Gabor
Published: January 2016

Stability prediction of machining operations is often not reliable due to the inaccurate mechanical modeling. A major source of this inaccuracy is the uncertainties in the dynamic parameters of the machining center at different spindle speeds. The so-called tip-to-tip measurement is the fastest and most convenient method to determine the frequency response of the machine. This concept consists of the measurement of the tool tip’s frequency response function (FRF) usually in two perpendicular directions including cross terms. Although the cross FRFs are often neglected in practical applications, they may affect the system’s dynamics. In this paper, the stability diagrams are analyzed for milling operations in case of diagonal, symmetric and non-symmetric FRF matrices. First a time-domain model is derived by fitting a multiple-degrees-of-freedom model to the FRF matrix, then the semi-discretization method is used to determine stability diagrams. The results show that the omission of the non-symmetry of the FRF matrix may lead to inaccurate stability diagram.
Decision Support for Performance Arts Using Support Vector Regression With Genetic and Particle Swarm Algorithms
Authors: Li Meifang , Li Mian
Published: January 2016

Different from typical mechanical products, tickets for movies and performing arts can be considered as a special type of consumer products. Compared to widely known box-office receipts prediction with single-output in movie industry, estimating the market share and price for performing arts is still a challenging problem due to high dimensional datasets yet limited number of samples. This paper describes a data-driven decision support system to help arts managers make strategic decisions, especially on session-determination and price-setting, considering price discrimination and prediction on the corresponding sales volume. Eight different attributes from the database, with multiple labels in each attribute, are used to accurately and comprehensively represent and classify the characteristics of performing arts in each genre. A web-based influence factor is also defined to quantify the popularity and publicity of performing arts. For this multi-input and multi-output problem, support vector regression (SVR) is employed and its optimal parameters are determined using genetic algorithm (GA) and particle swarm optimization (PSO) respectively. Price utility axiom with the law of demand is applied to maximize the receipts. Compared to artificial neural networks (ANN), those two optimization based SVR methods perform much better, in terms of effectiveness and reliability.
Qualitative Data Analysis in Product Development: An Exploration of Closed Loop Thinking in Product Requirements
Authors: Velte Christoph J. , Butzer Steffen , Steinhilper Rolf
Published: January 2016

As a reaction to resource scarcity and a growing conscience for environmental justice, closing product loops and thus eliminating land-filling or other product-dead-ends where possible becomes a task that many disciplines work on solving today. The most influential among those disciplines are the ones that mainly determine product lives, namely product design, business model, supply chain and the technology infrastructure.

Following the idea that the most influential phase determining product lives is product development and furthermore acknowledging that the way a product is developed is defined in the requirements given to the product development team, this paper describes two case studies where product requirements were analyzed concerning their closed-loop-thinking and the representation of the aforementioned disciplines using qualitative data analysis.

This proceeding adds a new perspective to product development analyses by examining the actual requirements, that are the formal representation of all product development instructions.
Automatic Structural Synthesis of Epicyclic Gear Trains With One Main Shaft
Authors: Ding Huafeng , Liu Shuai , Huang Peng , Cai Changwang , Huang Zhen
Published: January 2016

Design of automatic gear boxes with better performance is a pursuit goal of the modern automobile industry. In order to develop CAD method for the creative design of automatic gear boxes, this paper proposes an automatic method for the structure synthesis of one degree of freedom (DOF) epicyclic gear trains (EGTs) with one main shaft which serve as the key mechanisms in automatic gear boxes. First, based on the graph representation of EGTs, the canonical perimeter graphs and the corresponding canonical adjacency matrices are obtained. Then, based on the canonical adjacency matrices, the characteristic number strings are obtained and used to identify isomorphism in the synthesis process. Third, an automatic method is proposed to generate the basic graphs of the topological graphs of EGTs, and the basic graphs up to 9 links are synthesized. After that, based on the structural characteristics for the graphs of EGTs, an automatic method is proposed to synthesize the topological graphs of EGTs from the basic graphs, and an algorithm for the detection of rigid subchains in EGTs is also presented. Finally, a program is developed, and 1-DOF EGTs having one main shaft with up to 9 links are synthesized.
An Interactive Virtual User Interface for Integrating Blind Persons in Home Environments
Authors: Mengoni Maura , Cavalieri Lorenzo , Peruzzini Margherita , Raponi Damiano
Published: January 2016

Accessibility to graphical user interfaces by visually impaired persons is generally enabled through systems, which reproduce the lexical structure of the user interface to a non-visual form, mainly employing 3D audio output techniques. Two main critical issues have been identified: (i) most interfaces address the needs and abilities of sighted users and consequently the reproduction is only a translation from one language to another; (ii) blind users are generally not involved in the development stage due to the cost of prototyping. The present work proposes an interactive user interface to control a multi-sensory shower accessible by both sighted and blind users and able to adapt its control knob to reproduce Braille texts. Such function is realized by the integration of an electrotactile feedback device and adopts soft touch finishing to better stimulate touch sensations. Haptic technologies have been exploited to create a virtual high-fidelity prototype to assess individual end-users’ response during the user interface design process. The paper illustrates the designed interface to assist blind users in home environments and the adopted virtual prototyping technique to address the above-mentioned issues.
Coupled Multibody Dynamics and Discrete Element Modeling of Bulldozers Cohesive Soil Moving Operation
Authors: Sane Akshay , Wasfy Tamer M. , Wasfy Hatem M. , Peters Jeanne M.
Published: January 2016

Multibody dynamics and the discrete element method are integrated into one solver for modeling the excavation and moving operation of cohesive soft soil (such as mud and snow) by bulldozers. A soft cohesive soil material model (that includes normal and tangential inter-particle force models) is presented that can account for soil flow, compressibility, plasticity, fracture, friction, viscosity, gain in cohesive strength due to compression, and loss in cohesive strength due to tension. Multibody dynamics techniques are used to model the various bulldozer components and connect those components using various types of joints and contact surfaces. A penalty technique is used to impose joint and normal contact constraints. An asperity-based friction model is used to model joint and contact friction. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between the particles and polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. A numerical simulation of a bulldozer performing a shallow digging operation in a cohesive mud-type soil is presented to demonstrate the integrated solver. The solver can be used to improve the design of the various bulldozer components such as the blade geometry, tire design, and track design.
Corrugated Tube Inversion for Energy Absorption
Authors: Li Yang , You Zhong
Published: January 2016

Thin-walled tubes subjected to axial crushing have been extensively used as energy absorbers in transportation system. It has been known for some time that inversion of a circular tube can have very high energy absorption capability and a stable reaction force. However, its inversing mechanism is rather unstable, and it requires a lubricated contact surface, both of which largely hinder its wide application. This paper proposes to use corrugated tube for inversion, which provides a stable inversing mechanism and no requirement for lubricated contact. Furthermore to the improvement of inversing stability, a comparison between inversion of corrugated tube and buckling of circular tube has been done. It shows that the inversion of the corrugated tube has longer stroke, higher energy absorption capability and better load uniformity than that of buckling of circular tube.
The Dynamics of a Doubly Clamped Microbeam Near the Primary Resonance: Experimental and Analytical Investigation
Authors: Masri Karim M. , Jaber Nizar R. , Younis Mohammad I.
Published: January 2016

We present experimental and analytical investigation of the dynamics of a doubly clamped microbeam near its primary resonance. The microbeam is excited electrostatically by an electrode on the first half of the beam. These microbeams are fabricated using polyimide as structural layer coated with nickel from top and chromium and gold layers from bottom. A noise signal is applied to experimentally detect the natural frequencies. Then, frequency sweep tests are generated for various values of DC bias revealing hardening, transition, and softening behavior of the microbeam. We report for the first time the transition from lower stable state, to unstable state, and then to large stable state experimentally. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. Shooting method is used to find the periodic motion and is utilized to generate frequency response curves. The curves show good agreement with the experimental results with hardening behavior at lower DC voltage then softening at higher voltage loads and dynamic pull-in.
Coupled Multibody Dynamics and Smoothed Particle Hydrodynamics for Modeling Vehicle Water Fording
Authors: Wasfy Tamer M. , Wasfy Hatem M. , Peters Jeanne M.
Published: January 2016

Multibody dynamics and smoothed particle hydrodynamics (SPH) are integrated into one solver for predicting the water fording dynamic response of ground vehicles. Multibody dynamics models are used for the various vehicle systems including: suspension system, wheels, steering system, axles, differential, and engine. A penalty technique is used to impose joint and normal contact constraints (between the tires and ground, and between the tires/vehicle body and the fluid particles). An asperity-based friction model is used to model joint and contact friction. Water is modeled using an SPH particle-based approach along with a large eddy-viscosity turbulence model. A contact search algorithm that uses a Cartesian Eulerian grid around the water pool is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between polygonal contact surfaces (representing the tires and vehicle body) and the fluid particles. The governing equations of motion for the solid bodies and the fluid particles are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The integrated solver is used to predict the dynamic response of a Humvee-type vehicle moving through a shallow water pool.
Risk Identification Method for Engineering Design Project Based on Risk Chain Mechanism Model
Authors: Nomaguchi Yutaka , Dong Chunzhi , Nakashima Hirotaka , Fujita Kikuo
Published: January 2016

An engineering design project includes various types of uncertainties. They cause risk that a project goal cannot be accomplished within lead time. A design project manager should identify potential risk factors and causal relations among them in a project. Although it is worthwhile to spend much time on a workshop for project members to understand unnoticed risks, it is often a hard job to identify risk factors and causal relations in a mutually exclusive and collectively exhaustive way. This paper proposes a risk identification method based on a fundamental model of a risk chain mechanism in an engineering design project in order to support a project manager and project members to systematically identify potential risk factors and causal relations among them. A proposed method provides categories of typical risk factors in an engineering design project. A typical chain mechanism among those categories is also defined. Those elements in a fundamental model can facilitate a project manager and project members to find unnoticed factors in a project. A case study of a risk workshop for a student formula car design project is demonstrated to show that the proposed method facilitates project members to understand potential risk factors and to build a comprehensive risk chain model.
The Augmented Electronic Stability Program With Semi-Active Air Suspension Integrated
Authors: Wu Guangqiang , Guanghu Ye
Published: January 2016

To improve an automobile’s ride and comfort, handling and stability etc., based on the stiffness test of the air spring, a 15 DOFs vehicle model was created, a strategy of Augment Electronic Stability Program (AESP) with semi-active air suspension integrated was realized. Furthermore, their integrated control strategy combined both the skyhook and groundhook under critical operating conditions was proposed. The property of the vehicle with different control strategies under critical operating conditions of double-line change was simulated in both time and frequency domain, also the phase portrait of the vehicle concerning with the stability was provided, also the Safety Margin of the vehicle introduced in this paper was presented. It’s shown that the trajectory of the automobile is more ideal with AESP, the safety of automobile can be improved, the overall performance of vehicle is optimized as well.
Tactile Display for Virtual Shape Rendering Based on Servo Actuated Modules
Authors: Mansutti Alessandro , Covarrubias Rodriguez Mario , Bordegoni Monica , Cugini Umberto
Published: January 2016

This paper presents a new concept of a desktop tangible shape display for virtual surface rendering. The proposed system is able to represent in the real environment the shape of a digital model of a product, which can be explored naturally through a free-hand interaction. Aim of the shape display is to allow product designers to explore the rendered surface through a continuous touch of curves lying on the product shape. Ideally, the designer selects curves, which can be considered as style features of the shape, on the shape surface, and evaluates the aesthetic quality of these curves by manual exploration. In order to physically represent these selected curves, a flexible surface is modelled by means of servo-actuated modules controlling a physical deforming strip. The behaviour of the strip is controlled by acting on the position and rotations of a discrete number of control sectors. Each control sector is controlled by a module, which is based on an absolute positioning approach and equipped with five degrees of freedom. The developed system is able to manage the elastic behaviour of the strip in terms of bending, twisting and local tangency. The tangency control allows us to manage the local tangency of the strip to the rendered trajectory, thus increasing the accuracy of the representation. Moreover, a preliminary second version of the module is presented, which has been designed so as to allow the control sectors to slide on the strip. Thanks to this feature, it will be possible to place the control sector in a given point of the trajectory, such as point of maximum, point of minimum or inflection points. The device is designed to be portable, low cost, modular and high performing in terms of types of shapes that can be represented. A prototype equipped with three modules has been developed in order to evaluate the usability and the performances of the display.
Multi-Sensor Reverse Engineering Technique for the Acquisition of Centrifugal Pump Impellers
Authors: Traghella Daniele , Paoli Alessandro , Barone Sandro , Razionale Armando V.
Published: January 2016

The geometrical reconstruction of centrifugal pump impellers is a strategic activity for many manufacturing industries. In particular, the digitalization of internal hydraulic shapes represents the most critical task due to the difficulties in accessing the internal parts of impeller disks.

In this paper, an automatic approach to digitize the internal shape of impellers is presented. The methodology is based on the integration of optical and probing methods in order to combine the advantages of both technologies. The developed approach uses an optically tracked hand-held probe designed to digitize, point-by-point, the whole surface of blades. The tracking system is based on a passive device, composed of two stereo cameras, which is used to accurately locate a specific plate, rigidly connected to a probe. The proposed methodology has been validated by experimental tests on primitive surfaces as plane, cylinders and spheres. Nonetheless, the robustness and flexibility of the developed technique has allowed the whole reconstruction of industrial impellers through the acquisition of hundreds of points in few minutes.
Finding Breakthrough Points in Platformed Product Family Design
Authors: Arai Kohei , Oizumi Kazuya , Aoyama Kazuhiro
Published: January 2016

In product development, a design parameter, which designers can change directly, often has an adverse effect on several function metrics, which are indices that describe the product performance. This phenomenon is called a “tradeoff.” Traditionally, tradeoffs are considered for a single product. However, in recent years, there have been tradeoffs between several products because of communal design parameters in platform-based product family design. This problem makes it difficult to determine the point at which a technological innovation is profitable.

In this paper, the point where designers make a technological innovation is defined as a breakthrough. A method is suggested to find the effective breakthrough point for a product family. A model was developed that shows the relations between design parameters and function metrics from a quality function deployment (QFD) to comprehensively estimate the effectiveness of a technological innovation. As an example application, a prototype system was developed and applied to searching a solar boat product family for breakthrough points. The results showed that the proposed method effectively supports the decision-making of product designers.
Design of a Compliant XY Positioning Stage With Large Workspace
Authors: Huang Chao-Min , Su Hai-Jun
Published: January 2016

Flexure mechanisms become more and more popular because of their better performance, easy maintenance, wear-free properties and predictability of kinematic variables changes. Comparing to traditional ball bearings or linear slides, however, range of motion limits flexure mechanisms applications in existing market. This paper presents the design of a novel planar XY stage synthesizing the benefits of parallel and serial kinematic constraint. By parallel connecting two mechanisms: the vertical and horizontal subsystems, which both have degrees of freedom (DOFs) in primary moving direction but different degrees of constraints (DOCs) in rotation, this system is able to reduce three parasitic rotation angles (pitch, roll and yaw) less than one micro radium and also have motion range up to 40mm × 40mm. Analytical model and finite element analysis (FEA) are present to validate the performance of this stage and also determine appropriate operation parameters.
Transient Thermal Analysis of Brake Disc in Regenerative Braking System Using Finite Element Analysis
Authors: Pandya Parth
Published: January 2016

This paper proposes a design development process to analyze and optimize the design of a brake rotor for a Formula Student Electric Vehicle so as to minimize its weight and reduce thermal stress by keeping the rotor within its operating temperature during the entire braking duration. In today’s world where lesser energy consumption is essential, regenerative braking plays an important role, and is also a factor in weight reduction of brake discs. Regenerative braking is an effective method to maximize brake disc’s life, minimize pad wear and extend working range of electric vehicles. The proposed technique consists of using a tire model and building mathematical models in a MATLAB environment to find transient vehicle speed, which in turn provides wheel loads, frictional torque, braking power and heat flux to the brake disc as a function of time. The heat flux to brake disc increases its temperature and is dissipated mainly through convection, which is also a time-dependent parameter based on air velocity. The entire transient heat transfer model, which also depends on the geometry, material of the brake rotor and mechanical boundary conditions is setup in ANSYS FLUENT and ANSYS Transient Structural and simulation results are presented. Stress fields for floating rotor and fixed rotor are compared since fastening techniques also play a crucial role. Disc brakes are used in almost all ground vehicles and thus, the given design process is vital as the work presented can be extended and modified as per requirements to incorporate the needs of the specific situations one needs to work upon.
Case Study for Introductory Mechanical Design Competitions
Authors: Faas Daniela , Howe Robert D.
Published: January 2016

Freshman/sophomore design projects provide students with hands-on experiences in conceptual design and manufacturing. For some of these courses, a design competition is used to teach the design and construction components. These competitions are often reused from semester to semester, so the students typically suffer from design fixation. When design competition tables are erected new every single semester, it requires advanced planning and high budgets. This paper discusses a case study of a different structure for introductory design courses and competitions at Harvard. We summarize a yearlong effort to improve an existing early design competition with more machine component elements and linkage design. The goal of a interchangeable design competition was to prevent design fixation while at the same time providing boundaries for students to successfully implement their robot designs, independent of their previous mechanical engineering exposure.
Exploring Decision Tradeoffs in Sustainable Design
Authors: Mattson Christopher A. , Lofthouse Vicky , Bhamra Tracy
Published: January 2016

Sustainable design involves three essential areas: economic sustainability, environmental sustainability, and social sustainability. For even the simplest of products, the complexities of these three areas and their tradeoffs cause decision-making transparency to be lost in most practical situations. The existing field of multiobjective optimization offers a natural framework to explore the tradeoffs in the sustainability space (defined by economic, environmental, and social sustainability issues), thus offering both the designer and the decision makers a means of understanding the sustainability tradeoffs. To facilitate this, a decision making approach that capitalizes on the principles and power of multiobjective optimization is presented. This paper concludes that sustainable development can indeed benefit from tradeoff characterization using multiobjective optimization techniques — even when using only basic models of sustainability. Interestingly, the unique characteristics of the three essential sustainable development areas lead to an alternative view of some traditional multiobjective optimization concepts, such as weak Pareto optimality. The sustainable engineering design of a hypodermic needle is presented as a simple hypothetical example for method demonstration and discussion.
A Review of Anti-Lock Braking System Configuration for Two-Wheeled Vehicle
Authors: Yu Liangyao , Huo Shuhao , Liu Xiaohui , Liu Xiaoxue
Published: January 2016

Anti-Lock Braking Systems (ABS) have been developed and integrated into vehicles since it is invented more than thirty years ago. However, most of nowadays ABS are designed for multi-wheeled passenger cars, commercial cars and trucks. Due to the technical complexity and additional cost, ABS is not as common on two-wheeled vehicles, such as motorcycle, electric scooter, electric bike, etc. Study shows that injuries and deaths in relation to two-wheeled vehicles with ABS are significantly decreased. This paper is to provide a brief review of the state-of-the-art on the ABS configuration of two-wheeled vehicles.
Kinematic Analysis of Congruent Multilayer Tessellations
Authors: Klett Yves , Middendorf Peter
Published: January 2016

Rigidly foldable origami tessellations exhibit interesting kinematic properties. Several tessellation types (most prominently Miura-ori) have shown potential for technical application in aerospace and general lightweight construction. In addition to static (e.g. as core structures for sandwich components) and single-layer kinematic (e.g. deployable) applications, new possibilities arise from the combination of several layers of tessellations with congruent kinematics. This paper presents an analytical description of the kinematics of multi-layered, or stacked, globally plane tessellations which retain rigid foldability by congruent, compatible movement.
Automatic Generation of Software Interfaces for Hand-Tracking Devices
Authors: Colombo Giorgio , Rizzi Caterina , Facoetti Giancarlo , Vitali Andrea
Published: January 2016

This paper presents a software module, named tracking plug-in, developed to automatically generate the source code of software interfaces for managing the interaction with low cost hand-tracking devices (e.g., Leap Motion and Intel Gesture Camera) and replicate/emulate manual operations usually performed to design custom-fit products, such medical devices and garments. The proposed solution is based on the Eclipse platform, a free integrated development environment (IDE), that allow us to manage the automatic code generation in a simple way after having defined the target application using a meta-model language, in our case the UML class diagram. First, we describe the background as well as the main problem, then, the software solution and adopted tools (i.e., Eclipse and Acceleo). Finally, the preliminary tests carried out for two applicative contexts (prosthetic and textile/clothing) are presented.
Regional Responses of Rat Brain to Impactor Parameters
Authors: Hua Yi , Akula Praveen , Kelso Matthew , Gu Linxia
Published: January 2016

The closed head impact (CHI) rat models are commonly used for studying the traumatic brain injury. Although various impact parameters (e.g., impact depth, velocity, and position) have been investigated by a number of researchers, little is known about the effects of the impactor shape, diameter, and material on the internal responses of the rat brain. In this work, numerical CHI experiments were conducted to investigate the sensitivities of intracranial responses to the impactor details such as impactor shape, diameter, and material. A 3D finite element rat head model with anatomical details was subjected to impact loadings. Results revealed that the impactor shape can affect the intracranial responses significantly. The effect of impactor diameter on the intracranial responses in different brain regions was uniform. In addition, careful attention should be paid when using an extremely compliant material for the impactor, since the actual impact depth might be compensated by the impactor deformation.
Design of Mechanism and Preliminary Field Validation of Low-Cost, Passive Prosthetic Knee for Users With Transfemoral Amputation in India
Authors: Arelekatti V. N. Murthy , Winter Amos G.
Published: January 2016

An estimated 230,000 above-knee amputees in India are currently in need of prosthetic care, a majority of them facing severe socio-economic constraints. However, only few passive prosthetic knee devices in the market have been designed for facilitation of normative gait kinematics and for meeting the specific daily life needs of above-knee amputees in the developing world. Based on the results of our past studies, this paper establishes a framework for the design of a low-cost prosthetic knee device, which aims to facilitate able-bodied kinematics at a low metabolic cost. Based on an exhaustive set of functional requirements, we present a prototype mechanism design for the low-cost prosthetic knee. The mechanism is implemented using an early stance lock for stability and two friction dampers for achieving able-bodied kinematics and kinetics of walking. For early-stage validation of the prosthesis design, we carry out a preliminary field trial on four above-knee amputees in India and collect qualitative user feedback. Future iterations of the mechanism prototype will incorporate an additional spring component for enabling early stance flexion-extension.
A System of System Approach for Smart Complex Energy System Operation Decision
Authors: Jafari-Marandi Ruholla , Hu Mengqi , Chowdhury Souma
Published: January 2016

The emerging technology in smart grids enables a bi-directional communication between buildings and power grids. Not only can a building request energy from power grid, but it is also able to sell surplus energy back to power grid or to its neighborhood buildings. The vision is that multiple residential houses can freely form a smart complex to share energy and exchange information, which is expected to reduce energy consumption and achieve significant energy cost savings. However, the study of the operation decisions of a smart complex with multiple residential buildings is limited in the literature. To address this research gap, this paper proposes a System of Systems (SoS) approach to investigate the smart complex operation that considers a residential complex setting where all of the households are connected to one another through the complex virtual decision making level, while maintaining their preferred comfort level. The core objective of the proposed model is to minimize the cost of energy for all of the households in the complex which can freely share energy and exchange information. Each household has the flexibility to maintain its comfort level while minimizing the energy cost. Two mathematical models are presented: (i) at complex level, and (ii) at household level. Although each household is given the freewill to set its comfort levels while optimizing energy costs, the interconnection of these houses with shared renewable energy systems and a complex size battery can boost the load shifting. To derive the operation decision for the smart complex, a genetic algorithm (GA) is developed, and a case study is used to test the efficiency of this GA. It was found that the GA provides acceptable levels of convergence within a reasonable time frame, thereby exhibiting potential for use in real-time decision making in the smart grid context.
Design of a Biologically Inspired Underwater Burrowing Robot That Utilizes Localized Fluidization
Authors: Dorsch Daniel S. , Winter Amos G.
Published: January 2016

The Atlantic razor clam (Ensis directus) digs by contracting its valves, fluidizing the surrounding soil and reducing burrowing drag. Moving through a fluidized, rather than static, soil requires energy that scales linearly with depth, rather than depth squared. In addition to providing an advantage for the animal, localized fluidization may provide significant value to engineering applications such as vehicle anchoring and underwater pipe installation. This paper presents the design of a self-actuated, radially expanding burrowing mechanism that utilizes E. directus burrowing methods. The device is sized to be a platform for an anchoring system for autonomous underwater vehicles. Scaling relationships presented allow for design of burrowing systems of different sizes for a variety of applications. The motion to sufficiently create soil fluidization is presented. Max force for the actuator to contract is based on force to pump fluid out of the device, and max expansion force is determined by the soil. Friction force in the device and potential considerations for increased force are presented. Data from laboratory tests are used to characterize how power is split between pumping water out of the device versus accelerating the mechanism itself. These relationships provide the optimal sizing and power needs for various size subsea burrowing systems.
Finding Periodic Solutions of Forced Systems With Local Nonlinearities: A Mixed Shooting Harmonic Balance Method
Authors: Schreyer Frederic , Leine Remco
Published: January 2016

Several numerical approaches have been developed to capture nonlinear effects of dynamical systems. In this paper we present a mixed shooting-harmonic balance method to solve large mechanical systems with local nonlinearities efficiently. The Harmonic Balance Method as well as the shooting method have both their pros and cons. The proposed mixed shooting-HBM approach combines the efficiency of HBM and the accuracy of the shooting method and has therefore advantages of both.
Investigation of Wave Propagation Behavior in Magnetically Coupled MEMS Oscillators
Authors: Little Jared A. , Carroll Robin , Mazzoleni Michael J. , Garraud Nicolas , Arnold David P. , Mann Brian P.
Published: January 2016

This paper investigates the dynamic behavior of a 1D array of magnetically coupled MEMS oscillators. To facilitate future research and innovation, this paper details the model used to predict wave propagation behavior in the microfabricated array. The investigations model the oscillator array as a series of clamped-clamped beams that are coupled via magnetic proof masses. The contributions to system dynamics of the beam and magnetic interactions of each oscillator are theorized. Finally, the dynamic behavior for the entire array is investigated with a series of theoretical trend studies.
A Structural Equation Modeling Based Approach for Identifying Key Descriptors in Microstructural Materials Design
Authors: Zhang Yichi , Apley Daniel W. , Chen Wei
Published: January 2016

In design of advanced heterogeneous materials system, microstructures play an important role as a link between processing and material properties. An accurate and efficient representation of material microstructures is necessary. Our prior work applied a supervised ranking algorithm to identify key microstructure descriptors, however the approach falls short in identifying redundancy in descriptors and is not reliable when the training sample size is small. In this paper, we propose a Structural Equation Modeling (SEM) based approach to identify significant microstructure descriptors based on either correlation functions (CF) or material properties, or both. By building a reflective structural model, we are able to deal with high correlations among all candidate descriptors, gain more insights into their relations, and identify latent factors for categorizing microstructure features. The proposed approach begins with an Exploratory Factor Analysis (EFA) for grouping and reducing descriptors to determine the proper structure of microstructure descriptors as indicators of latent factors. The SEM analysis is then applied to identify the key descriptors using the Partial Least Squares (PLS) algorithm. The nanodielectric system with epoxy-nanosilica is used as an example to illustrate and validate the proposed approach. The potential use of identified key microstructure descriptors for optimal design of microstructural materials is discussed.
Using Multivariate Analysis to Select Accommodation Boundary Manikins From a Population Database
Authors: Boyd Devon K. , Parkinson Matthew B.
Published: January 2016

Digital Human Models (DHMs) are a tool that can be used to aid in determining dimensions for human-centered designs. DHMs have the ability to represent the anthropometric extremes of the population and help to determine which dimensions should be used to acquire a certain level of accommodation within a population. It is not possible to use current techniques for selecting manikins that represent a population, like principal component analysis (PCA), the application of design families, or percentiles due to these methods having a lower output accommodation levels than expected. The purpose of this research is to provide a multivariate analysis based on Pareto optimization. This method determines a pool of manikins representing the total target population when comparing up to three anthropometric dimensions within a database. This pool will act as boundary manikins for a given level of accommodation.
Optimization on Metamodeling-Supported Iterative Decomposition
Authors: Hajikolaei Kambiz Haji , Cheng George , Wang Gary
Published: January 2016

The recently developed metamodel-based decomposition strategy relies on quantifying the variable correlations of black-box functions so that high dimensional problems are decomposed to smaller sub-problems, before performing optimization. Such a two-step method may miss the global optimum due to its rigidity or requires extra expensive sample points for ensuring adequate decomposition. This work develops a strategy to iteratively decompose high dimensional problems within the optimization process. The sample points used during the optimization are reused to build a metamodel called PCA-HDMR for quantifying the intensities of variable correlations by sensitivity analysis. At every iteration, the predicted intensities of the correlations are updated based on all the evaluated points and a new decomposition scheme is suggested by omitting the weak correlations. Optimization is performed on the iteratively updated sub-problems from decomposition. The proposed strategy is applied for optimization of different benchmark and engineering problems and results are compared to direct optimization of the undecomposed problems using Trust Region Mode Pursuing Sampling method (TRMPS), Genetic Algorithm (GA), and Dividing RECTangles (DIRECT). The results show that except for the category of un-decomposable problems with all or lots of strong (i. e., important) correlations, the proposed strategy effectively improves the accuracy of the optimization results. The advantages of the new strategy in comparison with the previous methods are also discussed.
Human-Centric LED Lighting System Using Ubiquitous Physiological Monitoring
Authors: Sun Ye , Liu Zhen
Published: January 2016

The aging population, prevalence of chronic diseases, and depression are some of the major challenges of current healthcare. The smart home monitoring provides a solution of human-centric out-of-hospital care and calls for more attention to improve the comfort of patients. Among home technologies, electric lighting system is ubiquitous and affecting many aspects of human physiology, including not only visual system but also non-image-forming system. The exposure to light can influence various states of human and lead to effective comforting.

This paper presents a human-centric smart lighting system controlled by human state using ubiquitous physiological sensor networks. The proposed system, acting as an intelligent home monitoring component, can naturalistically detect human’s state such as intensiveness, sleepiness, and depression. Vital signals including ECG and its secondary parameters can be acquired by non-intrusive physiological sensors and wirelessly transmitted to a control system. The color of LED can be controlled by the detected human state and adjusted to emotional comfort. The results show that different colors of light can influence human’s state.