bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian Network Structure Optimization for Improved Design Space Mapping for Design Exploration With Materials Design Applications
Authors: Sharpe Conner , Morris Clinton , Goldsberry Benjamin , Seepersad Carolyn Conner , Haberman Michael R.
Published: November 2017

Modern design problems present both opportunities and challenges, including multifunctionality, high dimensionality, highly nonlinear multimodal responses, and multiple levels or scales. These factors are particularly important in materials design problems and make it difficult for traditional optimization algorithms to search the space effectively, and designer intuition is often insufficient in problems of this complexity. Efficient machine learning algorithms can map complex design spaces to help designers quickly identify promising regions of the design space. In particular, Bayesian network classifiers (BNCs) have been demonstrated as effective tools for top-down design of complex multilevel problems. The most common instantiations of BNCs assume that all design variables are independent. This assumption reduces computational cost, but can limit accuracy especially in engineering problems with interacting factors. The ability to learn representative network structures from data could provide accurate maps of the design space with limited computational expense. Population-based stochastic optimization techniques such as genetic algorithms (GAs) are ideal for optimizing networks because they accommodate discrete, combinatorial, and multimodal problems. Our approach utilizes GAs to identify optimal networks based on limited training sets so that future test points can be classified as accurately and efficiently as possible. This method is first tested on a common machine learning data set, and then demonstrated on a sample design problem of a composite material subjected to a planar sound wave.
Friction Model Using Full Elastohydrodynamic Lubrication for Spiral Bevel Gears
Authors: Gopalakrishnan Srikumar C. , Wang Yawen , Lim Teik C.
Published: November 2017

Elastohydrodynamic lubrication phenomenon in spiral bevel gears was modeled in this study. The coefficient of friction calculated from the elastohydrodynamic (EHL) lubrication model is time varying. Friction is expected to have a greater impact on the spiral bevel gears than on any other right angled geared system due to the reversal of the contact area over a full tooth-to-tooth engagement cycle. The coefficient of friction formulated from an EHL model of spiral bevel gears depends upon lubricant properties, mesh forces and rotational speeds of the pinion and gear. Hence in this present study, a full elastohydrodynamic lubrication model was used to calculate the coefficient of friction in spiral bevel gears. The geometric and kinematic input data required for the EHL simulations were obtained from tooth contact analysis. Full numerical elastohydrodynamic lubrication simulations were carried out using the asymmetric integrated control volume (AICV) algorithm to compute the contact pressures and the coefficient of friction. The elastic deformations on the gear contact surfaces were calculated by circular convolution using a Fourier transform technique. The computed pressures, film thickness and the effective viscosity were used to calculate the time varying coefficient of friction for the spiral bevel gears. Parametric studies were conducted by varying the speed, torque applied, lubricant properties, temperature and slide to roll ratio to identify their impact on the time varying coefficient of friction.
On the ESO Based Reinforcement Learning for Pure Feedback Systems
Authors: Li Dazi , Wang Wei , Gao Zhiqiang
Published: November 2017

The control of pure feedback system, which is widely used but has non-affine property, has always been an important and challenging problem. In order to achieve precise tracking control of pure feedback system through improving the disturbance rejection ability of existing reinforcement learning algorithm, a reinforcement learning (RL) control strategy based on extended state observer (ESO) is proposed in this paper. In the proposed method, the extended state observer can reject the total disturbances and transform the pure feedback system which is in an input-output predictor from to overcome the non-causal problem into a cascade integral form. This allows the continuous reinforcement learning strategy of the actor-critic (AC) structure not to depend on the detailed model information, which makes it practically data-driven. It is worth noting that, in order to further improve the ability to track the changing reference trajectory, a novel curvature acceleration factor is proposed, which can adjust the learning speed of the reinforcement learning controller according to the curvature of the reference trajectory. The validity of the proposed algorithm is verified by the simulation results.
Design of a New Waist for a Hexapod Robot With Parallel Leg Mechanism to Increase its Stair-Climbing Capability
Authors: Liu Jimu , Gao Feng , Chen Xianbao
Published: November 2017

A hexapod robot with parallel leg mechanism has been developed for rescue missions in nuclear power plants. The 1-UP & 2-UPS parallel leg mechanism has high payload but limited workspace which prevents the robot from climbing steep stairs. In this paper, a simple graphic method is proposed to estimate the robot’s stair-climbing capability based on its legs’ workspaces. The influence of the robot’s pitch motion on its payload capability is analyzed. Then a new waist mechanism which consists of a dual-parallelogram architecture is designed for the robot to increase its stair-climbing capability. Finally a simulation is carried out to demonstrate the robot’s stair-climbing capability with the help of the waist mechanism, and a prototype has been built and tested.
Design of a Beetle Inspired Deployable Wing
Authors: Saito Kazuya , Tachi Tomohiro , Niiyama Ryuma , Kawahara Yoshihiro
Published: November 2017

This study primarily proposes a procedure to design a crease pattern for beetle-inspired deployable wings based on the hindwings in relatively large-sized beetles like horn beetle or chafer. First, we discuss the representative patterns of wing supports and crease lines based on previous entomological research and propose a basic geometry for the artificial wing. Next, the flat foldability and rigid foldability of the proposed crease pattern are discussed based on origami geometry. Geometrical restrictions for flat- and rigid-foldable wings are numerically expressed as a function of the design parameters, and the Newton-Raphson method is used to compute the actual solutions. Although researchers have attempted to characterize the representative crease patterns found in beetles, only flat foldability has been considered in previous research. Our proposed method enables the design of rigid-foldable wings based on beetle-inspired patterns, which is considered beneficial in designing the deployable structures.
Biomechanical Design of a Novel Six DOF Compliant Prosthetic Ankle-Foot 2.0 for Rehabilitation of Amputee
Authors: Nguyen Tan Thang , Dao Thanh-Phong , Huang Shyh-Chour
Published: November 2017

This paper develops a new design of a compliant prosthetic ankle-foot 2.0. The ankle-foot is a composite made of glass-fiber reinforced plastic (GFRP). The finite element analysis is used to evaluate the structural behavior of the ankle-foot, including the deformation, stress and strain energy. The Taguchi method is used to build a special orthogonal array. By using a differential evolution algorithm, the geometric parameters of the ankle-foot are determined. The result indicated that the optimal strain energy is improved approximately 155%. The maximum energy strain of 93.914 mJ is recognized. The results also revealed that the prosthetic ankle-foot is becoming more flexible due to the compliant ankle. Lastly, the prosthetic ankle-foot was proved to be effective for a human body up to 100 kg.
An Interactive Design Method Based on Dual-Domain Transformations
Authors: Liu Yunhui , Peng Qingjin , Xiao Yu , Zhang Jian , Gu Peihua
Published: November 2017

This paper proposes an interactive method for product design based on dual-domain transformations from the principle domain to physical domain. The method considers that product design is a process to search proper actions or reactions to interact with product’s surroundings. Such actions or reactions are used to develop elements of a product by building energy-flow and force-path connections. The actions and reactions of energy flows, force paths, space and interface constraints are physically formed through the dual-domain transformation. A multi-purpose electric vehicle is developed using the proposed method.
Numerical and Experimental Study of Radial Impact Test of an Aluminum Wheel: Towards Industry 4.0 Virtual Process Assessment
Authors: Ballo F. , Frizzi R. , Gobbi M. , Mastinu G. , Previati G. , Sorlini C.
Published: November 2017

The paper deals with a numerical and experimental study of the radial impact test of an automotive aluminum wheel. The final aim is the confident virtual execution of the test in view of a pervasive digitalization of the aluminum wheel production process.

A finite element based model is developed. The model includes tire, wheel, striker and supporting structure. The actual structure of the tire is modeled. Tire damping is included through a Rayleigh model. The Rayleigh’s parameters are experimentally identified. The wheel material inhomogeneity is taken into account by assigning different stress/strain curves to wheel rim and spokes. The material curves have been experimentally measured considering specimens extracted from three different regions of actual wheels. The dynamic impact test is simulated by means of a nonlinear explicit solver.

Experimental tests on an impact test bench have been realized to validate the developed model. Accelerations during the impact test are measured on the striker. The impact force at the striker is measured by two load cells. The deformation of the wheel is measured by strain gauges located at the most critical areas of the wheel rim and spokes.

A good agreement between measured and simulated quantities is obtained. An accurate model of the impact test is now available including a digital representation of the qualification process of aluminum wheels.
Dexterous Gripper Synthesis From Modular Finger Approach
Authors: Rahman Nahian , Canali Carlo , Caldwell Darwin G. , Cannella Ferdinando
Published: November 2017

Dexterous gripper requirements, such as in-hand manipulation is a capability on which human hands are unique at; numerous number of sensors, degree of freedom, adaptability to deal with plurality of object of our hand motivate the researchers to replicate these abilities in robotic grippers. Developments of gripper or grasping devices have been addressed from many perspectives: the use of materials in the gripper synthesis, such as rigid or flexible, the approach of control, use of under-actuated mechanism and so on. Mathematical formulation of grasp modeling, manipulation are also addressed; however, due to the presence non-holonomic motion, it is difficult to replicate the behaviors (achieved in model) in a physical gripper. Also, achieving skills similar to human hand urge to use soft or non rigid material in the gripper design, which is contrary to speed and precision requirements in an industrial gripper. In this dilemma, this paper addresses the problem by developing modular finger approach. The modular finger is built by two well known mechanisms, and exploiting such modular finger in different numbers in a gripper arrangement can solve many rising issues of manipulation.
Noise Reduction in an Acoustic Cavity Using a Nonlinear Membrane Driven by an Electroacoustic Device
Authors: Bryk Pierre-Yvon , Bellizzi Sergio , Côte Renaud
Published: November 2017

In this paper an electro-Acoustic Nonlinear Absorber (ANLA) is described. It is composed of a baffled nonlinear membrane with its front face coupled to an acoustic cavity and the other one enclosed. The enclosure includes a feedback loop composed of a microphone and a loudspeaker that control the acoustic pressure seen by the rear face of the membrane. Due to the nonlinear geometrical properties of the membrane, the ANLA can synchronize it resonance with one of the resonances of the cavity. It allows to bring out the energy transfer toward the ANLA and thus to reduce pressure in the cavity. The feedback loop tunes the resonance frequency of the ANLA at low level, wich is a key factor for the triggering threshold of the targeted energy transfer. An numerical study of the efficiency of the ANLA to reduce noise in a cavity is presented including the influence of the feedback loop parameters.
Design Strategies for Vacuum Micro-Grippers With Integrated Release System
Authors: Ruggeri Serena , Fontana Gianmauro , Legnani Giovanni , Fassi Irene
Published: November 2017

The current miniaturization of several products requires manufacturing systems and methods able to meet the demanding specifications in terms of precision, efficiency, flexibility and reconfigurability. In particular, the manipulation and assembly of micro-components to obtain such products represent a crucial and challenging phase. For this reason, gripping tools have an essential role. At the micro-scale, the effects of adhesion forces can negatively affect the success and the precision of the manipulation operations, causing unexpected gripping or preventing the release of the components. Therefore, new micro-grippers and suitable release strategies have to be designed and developed to ensure high performance, overcoming the issues typical of the micro-scale. Among the different types of micro-grippers, vacuum micro-grippers represent a suitable tool to manipulate fragile and small components. In this context, this paper discusses different designs of an innovative vacuum micro-gripper integrating a simple and effective release system. The basic working principle is discussed and the related prototype is shown. Finally, a new design enhancement is also introduced to extend its applicability and release capability.
Design Process of High Dynamics Multi-Link Flexible Robot Manipulators
Authors: Solatges Thomas , Rognant Mathieu , Rubrecht Sébastien , Courteille Eric , Bidaud Philippe
Published: November 2017

This paper presents a design process based on an advanced flexible robots modeling tool associated with realistic actuators models and pre-defined control architecture. This process implements dedicated feasibility and performance indicators, which are used to evaluate a design and its sensitivity on the considered parameters. The proposed approach is illustrated with theoretical and experimental results obtained with the YAKA robot.
A Semi-Analytical Tyre Model for the Study of Tyre/Rim Interaction on a Road Vehicle
Authors: Ballo Federico , Previati Giorgio , Gobbi Massimiliano , Mastinu Gianpiero
Published: November 2017

The paper is devoted to the study of a simplified model for passenger car tyres. The simplified model is mainly focused on the computation of the forces acting at the tyre/rim interface. A simple and reliable model able to predict such forces can be a valuable tool for wheels manufacturers, whose concerns are focused on the lightweight design of the wheel.

The simplified model is based on a semi-analytical approach to model the tyre. The model, given a limited set of input parameters, computes the reaction forces acting at the tyre/rim interface under a vertical load. The input parameters can be identified by simple experimental tests on the tyre under consideration.

Reaction forces obtained from the semi-analytical model are then compared against a more detailed finite-element model of the tyre.
Active Fault Tolerant Control of Remotely Operated Vehicles via Control Effort Redistribution
Authors: Baldini A. , Ciabattoni L. , Felicetti R. , Ferracuti F. , Monteriù A. , Fasano A. , Freddi A.
Published: November 2017

An active fault tolerant control technique for Underwater Remotely Operated Vehicles is proposed in this paper. The main objective is to develop a controller for the tracking problem, which is robust against possible actuator faults and failures. The main advantage of the proposed fault tolerant control scheme is to develop a unique controller, and thus a unique set of control parameters, regardless the presence of faults and failures. This is achieved through a redistribution of the control effort on the healthy actuators. Simulation results are provided to demonstrate the viability of the proposed fault accommodating technique.
A Computational Method for Formulation and Solution of Dynamical Equations for Complex Mechanisms and Multibody Systems
Authors: Wehage Kristopher , Ravani Bahram
Published: November 2017

This paper presents a computational method for formulating and solving the dynamical equations of motion for complex mechanisms and multibody systems. The equations of motion are formulated in a preconditioned form using kinematic substructuring with a heuristic application of Generalized Coordinate Partitioning (GCP). This results in an optimal split of dependent and independent variables during run time. It also allows reliable handling of end-of-stroke conditions and bifurcations in mechanisms, thereby facilitating dynamic simulation of paradoxical linkages such as Bricard’s mechanism that has been known to cause problems with some multibody dynamic codes. The new Preconditioned Equations of Motion are then solved using a recursive formulation of the Schur Complement Method combined with Sparse Matrix Techniques. In this fashion the Preconditioned Equations of Motion are recursively uncoupled and solved one kinematic substructure at a time. The results are demonstrated using examples.
Computational Evaluation of the Haemodynamic Performance of a Novel Prosthetic Heart Valve
Authors: Mathur Mrudang , Saxena Ankit , Shad Rohan , Chattoraj Anwesha
Published: November 2017

It has become evident through studies both computational and otherwise, that the characteristics of blood flow through a mechanical heart valve is closely tied to its thrombogenic profile and clinical performance. Despite progress in the field, there remains an unmet clinical need for a heart valve that is both durable and free from the need for anticoagulation therapy. We designed a prototype for a novel mechanical heart valve with the aim of improving hemodynamic performance and obviating the need for anticoagulant therapy. In this paper we present the results of a computational study that compared our prototype mechanical heart valve with a popular commercially available valve, the Medtronic ATS valve. Our results show that the unique design features of our prototype leads to a reduction turbulent flow, along with a reduction in velocity jets by up to 28%, pressure gradient across the valve by 36.7%, and increases in the effective orifice area of the valve by 25.7%.
Null Space Method of Differential Equation Type for Motion Analysis of Multibody Systems
Authors: Kamiya Keisuke , Yamashita Yusaku
Published: November 2017

The governing equations of multibody systems are, in general, formulated in the form of differential algebraic equations (DAEs) involving the Lagrange multipliers. For efficient and accurate analysis, it is desirable to eliminate the Lagrange multipliers and dependent variables. Methods called null space method and Maggi’s method eliminate the Lagrange multipliers by using the null space matrix for the constraint Jacobian. In previous reports, one of the authors presented methods which use the null space matrix. In the procedure to obtain the null space matrix, the inverse of a matrix whose regularity may not be always guaranteed. In this report, a new method is proposed in which the null space matrix is obtained by solving differential equations that can be always defined by using the QR decomposition, even if the constraints are redundant. Examples of numerical analysis are shown to validate the proposed method.
Investigating Grey-Box Modeling for Predictive Analytics in Smart Manufacturing
Authors: Yang Zhuo , Eddy Douglas , Krishnamurty Sundar , Grosse Ian , Denno Peter , Lu Yan , Witherell Paul
Published: November 2017

This paper develops a two-stage grey-box modeling approach that combines manufacturing knowledge-based (white-box) models with statistical (black-box) metamodels to improve model reusability and predictability. A white-box model can use various types of existing knowledge such as physical theory, high fidelity simulation or empirical data to build the foundation of the general model. The residual between a white-box prediction and empirical data can be represented with a black-box model. The combination of the white-box and black-box models provides the parallel hybrid structure of a grey-box. For any new point prediction, the estimated residual from the black-box is combined with white-box knowledge to produce the final grey-box solution. This approach was developed for use with manufacturing processes, and applied to a powder bed fusion additive manufacturing process. It can be applied in other common modeling scenarios. Two illustrative case studies are brought into the work to test this grey-box modeling approach; first for pure mathematical rigor and second for manufacturing specifically. The results of the case studies suggest that the use of grey-box models can lower predictive errors. Moreover, the resulting black-box model that represents any residual is a usable, accurate metamodel.
Experimental Exploration of Schallamach Waves in a Multibody Belt-Drive Dynamical System
Authors: Wu Yingdan , Varenberg Michael , Leamy Michael J.
Published: November 2017

A friction test experimental apparatus has been developed for measuring frictional behavior in a simple belt drive. The device is able to capture stick-slip instabilities in a simple belt-pulley system, which will further be used for experimental validation, and/or experimental updating, of flexible multibody simulators formulated to capture Schallamach wave behavior. Obvious transient and steady states have been detected in the experimentally-measured response of the system. To demonstrate its performance, we have investigated the effect of the loading conditions on the mean friction force developed on the belt. Both increasing the belt tension and resistance torque results in an increase in belt friction.
A Flexible Discrete Building Block Synthesis Approach As Basis for the Design of Planar Linkages
Authors: Laudahn Simon , Irlinger Franz , Abdul-Sater Kassim
Published: November 2017

In this paper we present a computational approximate synthesis procedure for the planar RR chain. Our approach is based on a grid search and takes an arbitrary amount of user-defined task positions for the two outer bodies of the chain and restrictions for both joints into account. The result of this synthesis approach is not only one optimal solution, but a list of several possible solutions which are ranked according to their performance. The approach aims at being used in building block-based synthesis procedures of more complex linkages. The method shall later be included into a CAD-integrated design tool for planar linkages.
The Relationship Between Fixation and Originality in Undergraduate Mechanical Engineering Students
Authors: LeGendre Alexander , Kershaw Trina C. , Peterson Rebecca L. , Bhowmick Sankha
Published: November 2017

The goal of the current work was to supplement our existing work on creativity with work on a key design hurdle: fixation. Design fixation was measured based on six features of a litter collector that was used as a physical example for students who were asked to design a ‘next generation litter collector’. We found that certain example features occurred more commonly than others. If less common features were present in a design, chances were greater that the design was highly fixated. Across the Mechanical Engineering program, mean fixation decreased for seniors compared to other students. Fixation and originality had an inverse correlation, although less so for seniors compared to freshmen. This is the first study that may provide insights into how design fixation can impede originality.
Sensitivity Analysis of Beam Cross-Section Stiffness Using Adjoint Method
Authors: Callejo Alfonso , Bauchau Olivier , Diskin Boris , Wang Li
Published: November 2017

The design optimization of rotorcraft through multidisciplinary aeroelastic models with hundreds of thousands of degrees of freedom requires a computationally efficient sensitivity analysis to obtain the objective function gradient. A fundamental part of rotorcraft analysis is the flexible multibody dynamics solver, which in the current work relies on an accurate three-dimensional representation of the beams. This paper presents the theoretical adjoint sensitivity analysis of the first structural analysis step, namely the computation of cross-sectional properties of the beams in the form of six-dimensional stiffness matrices. The adjoint equations are carefully derived, as are the derivatives of the objective function with respect to the design parameters. The method is then validated by comparing certain design sensitivities of a three-ply, composite cross-section with those obtained through real-step and complex-step numerical differentiation. The presented analysis allows the user to quantify the effect of basic structural parameters on fundamental sectional properties that can later be used in the full dynamic simulation.
Continuum Kinematics of a Planar Dual-Backbone Robot Based on Pseudo-Rigid-Body Model: Formulation, Accuracy, and Efficiency
Authors: Kuo Chin-Hsing , Chen Yen-Chun , Pan Ta-Yu
Published: November 2017

This paper introduces a pseudo-rigid-body-model (PRBM) approach for analyzing the kinematics of a planar dual-backbone continuum robot. Unlike common load-displacement PRBM studies, the presented PRBM approach is tailor-made for the displacement-displacement analysis of compliant mechanisms, where the relationship between the lengths of the “backbone” wires and the pose of the robot is to be explored. Based on a PRB 3R modelling, the forward kinematics of the robot can be formulated as a nonlinear system of eight equations. To validate the accuracy and efficiency of the approach, a series of case studies are performed via ANSYS simulation and experiments. The results show that 1) the computation time for solving forward kinematics via the PRB 3R approach is less than 0.16% of that via ANSYS simulation; 2) the maximum percentage position errors of the PRB 3R model are 0.47% and 1.96% in the x- and y-directions, respectively; and 3) the maximum percentage orientation error of the PRB 3R model is 2.23%, as compared with ANSYS simulation results. As a result, the proposed PRBM approach delivers a satisfied compromise between accuracy and efficiency for the kinematic analysis of the planar dual-backbone continuum robot.
Predicting Damping of a Cantilever Beam With a Bolted Joint Using Quasi-Static Modal Analysis
Authors: Jewell Emily A. , Allen Matthew S. , Lacayo Robert
Published: November 2017

Bolted joints are common in assembled structures and are a large contributor to the damping in these assemblies. The joints can cause the structure to behave nonlinearly, and introduce uncertainty because the effective stiffness and damping at the joint are typically unknown. Consequently, improved modeling methods are desired that will address the nonlinearity of the jointed structured while also providing reasonable predictions of the effective stiffness and damping of the joint as a function of loading.

A method proposed by Festjens, Chevallier and Dion addresses this by using a sort of nonlinear modal analysis based on the response of the structure to quasi-static loading. This was further developed by Allen and Lacayo and thoroughly demonstrated for structures with discrete Iwan joints. This work explores the efficacy of quasi-static modal analysis for 2D and 3D finite element models in which the geometry, contact pressure and friction in the joint are modeled in detail. The mesh density, contact laws, and other solver settings are explored to understand what is needed to obtain convergence for this type of problem. For the 2D case study, the effect of bolt preload and coefficient of friction are explored and shown to produce reasonable trends. Three dimensional models prove far more challenging and significant effort was required to obtain convergence and then to obtain results that are physically realistic; these efforts are reported as well as the lessons learned.
The Structure of Vulnerable Nodes in Behavioral Network Models of Complex Engineered Systems
Authors: Walsh Hannah S. , Dong Andy , Tumer Irem Y.
Published: November 2017

All methods associated with failure analysis attempt to identify critical design variables and parameters such that appropriate process controls can be implemented to detect problems before they occur. This paper introduces a new approach to the identification of critical design variables and parameters through the concept of bridging nodes. Using a network-based perspective in which design parameters and variables are modeled as nodes, results show that vulnerable parameters tend to be bridging nodes, which are nodes that connect two or more groups of nodes that are organized together in order to perform an intended function. This paper extends existing modeling capabilities based upon a behavioral network analysis (BNA) approach and presents empirical results identifying the relationship between bridging nodes and parameter vulnerability as determined by existing, network metric-based methods. These topological network robustness metrics were used to analyze a large number of engineering systems. Bridging nodes are associated with significantly larger changes in network degradation, as measured by these metrics, than non-bridging nodes when subject to attack (p < 0.001). The results indicate the structural role of vulnerable design parameters in a behavioral network.
The Creation of an Ontology to Examine Customer Needs
Authors: Nix Anthony , Lemke Mark , Stone Rob , Arlitt Ryan
Published: November 2017

Customer needs are one of the first items gathered and examined in the design process. Currently there are few methods of examining the collected customer needs to help designers track how much of the customer need space has been explored. None of the current prominent design texts provide an universally accepted categorization scheme to help categorize and examine collected customer needs. This paper ventures into the process of building an ontology that can be used to categorize and examine customer needs. The finalized ontology presented here went through 11 iterations and multiple inter-rater reliability tests throughout the creation process. The paper then discusses the possible uses of this scheme and how it can be utilized early in the design process to ensure that a thorough exploration of the customer need space is represented in the designers’ list of customer needs.
Design, Modeling and Lab Test of Electromagnetic Energy Harvester for Railway Vehicle Suspensions
Authors: Pan Yu , Liu Fengwei , Jiang Ruijin , Tu Zhiwen , Zuo Lei
Published: November 2017

To enable the smart technologies, such as the GPS, suspension active and semi-active controls and electromagnetic braking system, on the railway freight vehicles, the electricity is required and in needed. In this paper, we proposed a rack-pinion based freight train suspension energy harvester with mechanical-motion-rectifier (MMR) mechanism, to harvest the energy that usually dissipated and wasted during suspension vibration. The special mechanism with one way clutches engagement and disengagement during the working period makes the harvester convert the bi-direction suspension linear motion into a generator unidirectional rotation, which improve the transmission reliability and increase the energy harvesting efficiency. Nonlinear model of the energy harvester is established in this paper to analyze the dynamic characteristic of the freight train energy harvester and bench test are carried out to experimentally characterize the proposed energy harvester. The results show that under a certain freight vehicle suspension vibration condition, the proposed energy harvester can get a peak 292W and an average 34W power, which has a much better energy harvesting performance than any other existing energy harvesting technology used for the railway vehicles. Moreover, the proposed energy harvester can reach a 70% mechanical efficiency, which shows that the MMR’s advantage in improving the energy harvesting efficiency.
Impact Mechanics Parametric Studies With Applications to Dynamic Force Calibration
Authors: Vlajic Nicholas , Chijioke Ako
Published: November 2017

National Measurement Institutions have developed apparatuses that rely on impacting bodies to realize time-varying forces for dynamic calibration of force transducers. Within this manuscript, we present a reduced-order model to investigate the effects of structural and contact parameters on determining the frequency-dependent calibration function of the force transducer that is to be calibrated. The reduced-order model is validated with experimental measurements and is used to conduct parametric studies, wherein regions of single impact events and contact time are mapped out in parameter space. Although this study has been conducted with dynamic force calibrations in mind, the results presented here are of broader relevance to modal analysis and system identification.
Gear Tooth Bending Fatigue Life Prediction Using Integrated Computational Material Engineering
Authors: Oja Michael E. , Wink Carlos H. , Deo Nikhil , McDaniels Robert L. , Tryon Robert G. , Dey Animesh , Kulkarni Sanjeev M.
Published: November 2017

The paper presents a computational method to predict the cyclic life of gears subjected to single tooth bending fatigue, using VEXTEC’s VPS-MICRO® software. The project was a collaborative effort between Eaton - Vehicle Group and VEXTEC Corporation to replicate physical testing virtually, more specifically to virtually determine bending fatigue curves of gears made from different steels.

VPS-MICRO is based on VEXTEC’s patented Virtual Life Management® (VLM®) technology which includes computational microstructural damage models to simulate the fatigue performance and calculate the lifetime of various product configurations. The framework probabilistically estimates the fatigue behavior of a range of Eaton gears and other products.
Experiment Driven Local Optimization (EDLO) With an Application to Additive Manufacturing
Authors: Hamel J. M.
Published: November 2017

The rise of the use of additive manufacturing processes by engineering and research enterprises has greatly increased opportunities for decision makers to quickly evaluate complex geometries and components throughout the design process. This capability makes it possible to explore design trade-off for which computational or analytical models are not readily available, or are impractical to obtain given available time and resources. However, this often means that decision makers are forced to rely primarily on physical experiments for design data, and this greatly limits opportunities for the application of design optimization techniques. To meet this challenge, a new so-called “online” surrogate based optimization approach, called Experiment Driven Local Optimization (EDLO), has been developed. This approach is focused specifically on using approximation techniques and real-time online surrogate training to solve design optimization problems where the system objective function must be evaluated using physical experiments. As a result, this approach is ideally suited to design problems focused on components that are fabricated using additive manufacturing. This approach is capable of mitigating the effects of experimental uncertainty (or noise) in a design objective function, does not require close coordination between the objective function evaluations and the optimizer, and requires as few physical experiments as possible. These capabilities have been demonstrated through the use of several numerical test problems and also through a 3D printed compliant mechanism design problem. The results produced by the EDLO approach are encouraging and show that this new technique has the potential to move decision makers working with physical experiments and additive manufacturing away from engineering intuition and towards the greater potential of design optimization techniques.
Computational Reference Dynamical Model of a Multibody System With First Order Constraints
Authors: Jarzębowska Elżbieta , Augustynek Krzysztof , Urbaś Andrzej
Published: November 2017

The paper presents a development of a computational based procedure for generation of constrained system dynamical models. The constraints may be both holonomic and first order nonholonomic, either material or nonmaterial. The latter ones are referred to as programmed and they are imposed by a designer, a control engineer as a control goal, or may come from controlled system performance requirements. The procedure for generation of constrained dynamics provides then reference dynamical models, i.e. models whose solutions satisfy all the constraints put upon them. These models may serve as motion planners for control. The distinctions between the presented approach and the ones reported in the literature are that the constraints may be material or nonmaterial and the final equations of motion are derived in the reduced state form, i.e. constraint reaction forces are eliminated at the equations derivation level but not afterwards as in the case of the Lagrange approach. This is the essential advantage of our approach and this one computational procedure may serve both reference and control oriented dynamical models derivation. The procedure is applied to a manipulator model whose end effector is subjected to a programmed constrained.
Enhanced Gaussian Process Metamodeling and Collaborative Optimization for Vehicle Suspension Design Optimization
Authors: Tao Siyu , Shintani Kohei , Bostanabad Ramin , Chan Yu-Chin , Yang Guang , Meingast Herb , Chen Wei
Published: November 2017

Dynamic stability is a key performance metric of motor vehicles and has a direct impact on passenger experience and customer satisfaction. The desired vehicle dynamics behavior can be achieved by optimizing the design of vehicle suspensions. Two challenges are associated with this design optimization task. The first one arises from the large number (e.g., 40 or 50) of design variables in modern suspension systems. Such multitude of variables not only makes it expensive to build a training dataset for metamodeling purposes, but also renders accurate surrogate modeling extremely difficult. The second challenge is a lack of guideline for choosing a proper multidisciplinary design optimization (MDO) method for a single MDO problem such as one for vehicle suspension design. In this paper, an enhanced Gaussian process (GP) metamodeling technique is developed and several versions of the collaborative optimization (CO) method are compared via a vehicle suspension design problem. In our enhanced GP modeling method, the model parameters are efficiently estimated using the smoothing effect of the so-called nugget parameter to reduce the search space. In addition, various versions of the CO method are studied where the enhanced collaborative optimization (ECO) method is found to perform the best. A simplified ECO formulation is also investigated to provide insights for future engineering applications.
Realizing Origami Mechanisms From Metal Sheets
Authors: Crampton Erica B. , Magleby Spencer P. , Howell Larry L.
Published: November 2017

Consideration of a product’s manufacturability is a vital aspect of product design. When considering manufacturability of panels for origami-adapted products, there are trade-offs between panel design approaches as well as thickness-accommodation techniques. The use of bent sheet metal for panels shows promise as a panel design approach that mitigates several of these trade-offs. This paper describes a process that can be employed to use sheet metal in designs of origami-adapted mechanisms that utilize specific thickness-accommodation techniques. The process is demonstrated for a square-twist mechanism designed using the hinge shift technique for accommodating thickness in origami patterns. A Miura-ori mechanism is also shown in sheet metal. The characteristics of these bent panel approaches are discussed and compared to other approaches for designing panels for manufacturing. The use of bent sheet metal panels allows for mitigation of several trade-offs and shows the applicability of origami-adapted design to sheet metal.
Modeling and Analysis of Microfabricated Bulk Piezoelectric Disc Transformers
Authors: Barham Oliver M. , DeVoe Don L.
Published: November 2017

Piezoelectric voltage transformers (PTs) have many uses in electromechanical systems, including voltage transformation and galvanic isolation, and have been commercialized on the macro scale in electronics powering consumer laptop liquid crystal displays. The present work investigates PTs on smaller size scales, that are currently in the academic research sphere, with an eye towards applications including micro-robotics and other small-scale electronic and electromechanical systems. PTs and a competing technology, inductive electromagnetic voltage transformers, are compared on the basis of power and energy density, with PTs showing favorable trends for micro-system designers. Among PT topologies, bulk disc-type PTs, operating in radial extension modes, are a good candidate for microfabrication, and are considered here. Bulk disc-type PT analysis is based on constitutive equations of thin piezoelectric disc dynamics, and the standard piezoelectric radial mode disc dynamics equations are reviewed, followed by an alternate method of derivation, based on the Generalized Hamilton method. This alternate derivation shows the promise of the Hamilton method in potentially developing a full model of device behavior, including mechanical boundary conditions such as tethering, and predictions of device voltage gain, based on energy considerations. Additionally, experimental resonance frequencies of 4.00mm diameter, 0.13mm thick bulk disc PTs are compared with numeric and analytic results, showing good agreement.
A Lyapunov Proof of Stability for Parallel Controllers of SISO Systems
Authors: Zelenak Andy , Pitsch Meredith , Fernández Benito , Pryor Mitch
Published: November 2017

For dynamic systems, it is known that stability (in general) cannot be guaranteed for individually-stabilizing controllers in combination, so the combined system must be analyzed to ensure stability. This paper presents a simple, graphical proof of Lyapunov stability for parallel controllers of SISO, input-affine, autonomous systems. This encompasses a broad range of all linear autonomous systems and many nonlinear, autonomous SISO systems. The proof allows Lyapunov stability theory to be used instead of the more complex and restrictive passivity approach. The paper also explains why it is often desirable to place controllers in parallel.
Frequency Reconfigurable QHA Based on Kapton Origami Helical Tube for GPS, Radio and WiMax Applications
Authors: Liu Xueli , Yao Shun , Gibson John , Georgakopoulos Stavros V.
Published: November 2017

Origami tubes are deployed to realize a compactable and frequency reconfigurable quadrifilar helical antenna (QHA). The specific origami pattern is parametrically analyzed to help with antenna modelling and simulation at reconfigurable states. Two quadrifilars respectively on helical tube and bellow tube are proposed, and the quadrifilar on helical tube is fabricated with 4-mil Kapton substrate. Measured results show that this Kapton QHA can operate with right-handed circularly polarized (RHCP) radiation patterns at 4 reconfigurable states with: ±1dB RHCP gain bandwidth from 1.05 GHz-1.4 GHz at state 1 with total antenna height H = 203 mm; ±1dB RHCP gain bandwidth from 1.4 GHz-1.73 GHz at state 2 with total antenna height H = 168 mm; ±1dB RHCP gain bandwidth from 2.07 GHz-2.7 GHz at state 3 with total antenna height H = 69 mm; ±1dB RHCP gain bandwidth from 2.7 GHz-2.94 GHz and 3.26 GHz-3.66 GHz at state 4 with total antenna height H = 54 mm. Therefore, this antenna can be reconfigured and applied in space and remote communication applications, such as GPS (1.17 GHz-1.58 GHz), radio (2.305 GHz-2.315 GHz) and WiMax (3.5 GHz).
Exploration of Turning Strategies for an Unconventional Non-Anthropomorphic Bipedal Robot
Authors: Yu Jeffrey , Hooks Joshua , Ghassemi Sepehr , Hong Dennis
Published: November 2017

This paper presents our findings in exploring various approaches for turning on a novel prototype biped which takes inspiration from humanoids, but features fundamental differences that increase its stability while reducing its cost and complexity. This non-anthropomorphic robotic system modifies the traditional humanoid form by aligning the legs in the sagittal plane and adding a compliant element to the feet. As this approach to locomotion is relatively new, turning methods have yet to be explored. Turning on this unique platform is a nontrivial problem that we examined by adding additional DoF in the forms of arms or hip actuators. The turning strategies tested include using the hand or foot as a pivot point, utilizing the arms like a tail or reaction wheel, and adding another DoF to each leg. The methods were tested quantitatively to assess their rotational accuracy and qualitatively to evaluate their viability in certain situations.
Design Patterns for Visualization-Based Tools in Sustainable Product Design
Authors: Ramanujan Devarajan , Bernstein William Z. , Ramani Karthik
Published: November 2017

Most design activities involve exploring and comparing existing designs. Thus, adopting an eco-conscious approach in the design exploration process can aid environmentally sustainable product design (SPD). One approach for supporting exploration in SPD is through tools based on information visualization (InfoVis). The use of InfoVis for SPD allows data-driven exploration of solutions that is rapid, direct, and supports investigation of questions that the designer may not have identified. Previous work has demonstrated the utility of InfoVis tools for different facets of the lifecycle, e.g. redesign, supply chain exploration, and life cycle assessment. These tools focus on projecting sustainability-related implications back to design. However, to fully realize their potential, future tools must synthesize data in a manner that helps designers view the effects of a design change on all downstream stages. Such tools will have to work across multiple data types, visual representations, and stakeholders. In this paper, we take the first steps towards addressing this challenge by formulating design patterns for visualization and interaction of product lifecycle data. These design patterns were synthesized by reviewing previous works that have successfully created visualization-based tools for SPD. The suggested design patterns can, (1) serve as a guide for creating integrated visualization-based tools for SPD, and (2) help create reusable visual components that aid in quick interface wireframing.