bluuebunny/crossref_metadata_2025 huggingface dataset:
The Design and Analysis of a Compliant Constant-Force Mechanism
Authors: Xie Zhongtian , Qiu Lifang
Published: December 2016

Compliant constant-force mechanisms (CFM) are a type of compliant mechanism which produce a reaction force at the output port that does not change for a large range of input motion. This paper describes a new compliant CFM, introduces its design and configuration-improvement process. A finite element analysis (FEA) model of the compliant CFM was created to evaluate its constant force behavior. The FEA result shows that when the displacement is Δ = 4 mm, the compliant CFM maintains a nearly constant force in the operational displacement range of 1.31 mm to 4 mm with an error of 5.05%. The operational range accounts for 67% of the total motion. This compliant CFM can be used to regulate the contact force of a robot end-effector or as an electrical connector.
Dynamic Analysis of a Fractional-Order MEMS System Using 0-1 Test
Authors: Bassinello Dailhane G. , Balthazar Jose Manoel , Tusset Angelo M. , Piccirillo Vinicius
Published: December 2016

In this work, the 0-1 test is applied to investigate the nonlinear dynamics of the MEMS system, considering the influence of the damping, variation of the polarization voltage, influence of the nonlinear stiffness term, and the dynamic behavior of the system in fractional-order. Numerical results showed that the parameters studied are significant, indicating that the response can be either chaotic or periodic behavior. For fractional-order case, the results showed the influence of the derivative order on the dynamic (regular or non-periodic) of the MEMS system. To characterize these behaviors the 0-1 test was used once this is a good tool to characterize fractional-order differential systems.
A Pseudo Rigid Body Model of a Single Vertex Compliant-Facet Origami Mechanism (SV-COFOM)
Authors: Rommers Jelle , Radaelli Giuseppe , Herder Just
Published: December 2016

Recently, there has been an increased interest in origami art from a mechanism design perspective. The deployable nature and the planar fabrication method inherent to origami provide potential for space and cost efficient mechanisms. In this paper, a novel type of origami mechanisms is proposed in which the compliance of the facets is used to incorporate spring behavior: Compliant Facet Origami Mechanisms (COFOMs). A simple model that computes the moment characteristic of a Single Vertex COFOM has been proposed, using a semi-spatial version of the Pseudo-Rigid Body (PRB) theory to model bending of the facets. The performance of this PRB model has been evaluated numerically and experimentally, and showed performance comparable to a Finite Element model with 122 elements. The PRB model is a potential starting point for a design tool which would provide an intuitive way of designing this type of mechanisms including their spring behavior, with very low computational cost.
Higher-Order Plate Elements for Large Deformation Analysis in Multibody Applications
Authors: Ebel Henrik , Matikainen Marko K. , Hurskainen Vesa-Ville , Mikkola Aki
Published: December 2016

This study introduces higher-order three-dimensional plate elements based on the absolute nodal coordinate formulation (ANCF) for large deformation multibody applications. The introduced elements employ four to eight nodes and the St. Venant-Kirchhoff material law. A newly proposed eight-node element is carefully verified using various numerical experiments intended to discover possible locking phenomena. In the introduced plate elements, the usage of polynomial approximations of second order in all three directions is found to be advantageous in terms of numerical performance. A comparison of the proposed eight-node element to the introduced four-node higher-order plate elements reveals that the usage of in-plane slopes as nodal degrees of freedom has a negative effect on numerical convergence properties in thin-plate use-cases.
Effects of Parameter Selection on Oscillatory Behavior-Based Signal Decomposition for Bearing Fault Signature Extraction
Authors: Huang Huan , Baddour Natalie , Liang Ming
Published: December 2016

Oscillatory Behavior-based Signal Decomposition (OBSD) is a new technique which employs Morphological Component Analysis (MCA) and the Tunable Q-factor Wavelet Transform (TQWT) to decompose a signal into components consisting of different oscillatory behaviors rather than different frequency bands or scales. Due to the low oscillatory transients of bearing fault-induced signals, this method shows promise for application to effectively extract bearing fault signatures from raw signals contaminated by interferences and noise. In this paper, the application of OBSD to bearing fault signature extraction is investigated. It is shown that the quality of the results obtained via the OBSD is highly dependent on the selection of method-related parameters. The effects of each parameter on the performance of the OBSD for bearing fault signature extraction are investigated. The analysis is also validated by implementing the OBSD on experimental data collected from a test rig with a defective bearing.
Investigation of Wrench Accuracy for Parallel Manipulators
Authors: Notash Leila
Published: December 2016

In this paper, the wrench accuracy for parallel manipulators is examined and the solution sets of actuator forces/torques are investigated under variations in parameters and data. The subset of solution set that produces platform wrenches within the required lower and upper bounds are modeled using discrete and analytical methods. In addition, the formulation of the solutions that provide any platform wrench within the defined interval is examined. Intersection of these two sets, if any, results in the given interval platform wrench. Moreover, the dependency among the entries of the interval linear systems and its effect on the solution set is considered.

The discrete method is based on the discretization of solution set enclosure and validation at each increment, or the collection of the solutions of real linear relations for the discretized interval coefficient matrix and output vector. The analytical method for each solution set is based on the intersection of the pertinent closed half-spaces or the assembly of closed line segments that encompass the solution. Implementation of the methods to identify the solution for actuator forces/torques is presented on example parallel manipulators.
Multi-Level Flow-Based Markov Clustering for Design Structure Matrices
Authors: Wilschut Tim (T.) , Etman Pascal (L. F. P.) , Rooda Jacobus (J. E.) , Adan Ivo (I. J. B. F.)
Published: December 2016

For decomposition and integration of systems one requires extensive knowledge on system structure. A Design Structure Matrix (DSM) can provide a simple, compact and visual representation of dependencies between system elements. By permuting the rows and columns of a DSM using a clustering algorithm, the underlying structure of a system can be revealed. In this paper, we present a new DSM clustering algorithm based upon Markov clustering. The developed clustering algorithm is able to cope with the presence of ‘bus’ elements, returns multilevel clusters, is capable of clustering both directed as well as undirected DSMs, and allows the user to control the cluster results by tuning only three input parameters.
Discrete Kinematic Geometry in Testing Axes of Rotation of Spindles
Authors: Wang Delun , Wang Zhi , Wu Yu , Dong Huimin , Yu Shudong
Published: December 2016

The accuracy of actual motion of the spindle of a machine tool, a key performance index, is measured at a series of positions, and evaluated using a discrete kinematic geometry model. The kinematic geometry model, or more precisely a novel mechanism, is presented for the first time in this paper and validated using an apparatus consisting of a spindle, an artifact with double master ball and five displacement sensors as per ASME codes and standards [1]. The six kinematic parameters of the spindle with a single rotor — three translations and three rotations are obtained using the novel mechanism and the measurements. The theory of discrete kinematic geometry is employed to reveal the intrinsic properties of the trajectories traced by the characteristic lines of the rotor. In order to avoid the influences caused by the locations and directions of the measuring coordinate systems, the invariants of a discrete line-trajectory, particularly the spherical image curve and the striction curve [2], are introduced to deal with the discrete measurements. The global invariants, the approximated moving axis and the approximated fixed axis of the rotor in the error motion, independent of the assembling position of the double master balls on the rotor, are proposed to evaluate the rotational accuracy of spindles. The discrete kinematic geometry provides a new perspective and a theoretical base for assessing the accuracy of the spindle motion.
Product Usability: Is it a Criterion to Measure “Good UX” or a Prerequisite?
Authors: Ceccacci Silvia , Giraldi Luca , Mengoni Maura
Published: December 2016

What is User Experience (UX) and how does it relate to Usability? The understanding of the mutual relationship between UX and product usability has a strong impact on product design methodologies and on the design outcomes’ success.

This paper aims to investigate such relationship thanks to a set of experiments around the design of interactive products without demanding completeness of findings.
Experimental Investigation of 2:1 and 3:1 Internal Resonances in Nonlinear MEMS Arch Resonators
Authors: Ramini Abdallah , Hajjaj Amal , Younis Mohammad I.
Published: December 2016

We demonstrate experimentally internal resonances in MEMS resonators. The investigation is conducted on in-plane MEMS arch resonators fabricated with a highly doped silicon. The resonators are actuated electrostatically and their stiffness are tuned by electrothermal loading by passing an electrical current though the microstructures. We show that through this tuning, the ratio of the various resonance frequencies can be varied and set at certain ratios. Particularly, we adjust the resonance frequencies of two different vibrational modes to 2:1 and 3:1. Finally, we validate the internal resonances at these ratios through frequency-response curves and FFTs.
Designer’s Intuitive Ratings of Sustainability
Authors: Telenko Cassandra , Wood Kristin
Published: December 2016

Life cycle analysis (LCA) is often used to compare the sustainability of product concepts, but how our intuition factors into analysis and innovation is rarely considered. Intuitive evaluations of sustainability by designers not only help scope LCAs, but can be a dominant force in early stage decision making and concept creation. To elicit intuitive responses from experts, eight environmentally conscious products were presented to 22 designers as part of a professional workshop survey. Participants rated their own experience in design and sustainability and rated the sustainability and innovativeness of each product from low to high. These ratings are compared with available LCAs and environmental impact information. The results indicate that self-perceived expertise in sustainability does not significantly change perception of the sustainability of products and that sustainability ratings and innovativeness ratings were moderately correlated.
Design of a Compact Gravity Equilibrator With an Unlimited Range of Motion
Authors: Bijlsma Bob G. , Radaelli Giuseppe , Herder Just L.
Published: December 2016

A gravity equilibrator is a statically balanced system which is designed to counterbalance a mass such that any preferred position is eliminated and thereby the required operating effort to move the mass is greatly reduced. Current spring-to-mass gravity equilibrators are limited in their range of motion as a result of design limitations. An increment of the range of motion is desired to expand the field of applications. The goal of this paper is to present a compact one degree of freedom mechanical gravity equilibrator that can statically balance a rotating pendulum over an unlimited range of motion. Static balance over an unlimited range of motion is achieved by a coaxial gear train that uses non-circular gears. These gears convert the continuous rotation of the pendulum into a reciprocating rotation of the torsion bars. The pitch curves of the non-circular gears are specifically designed to balance a rotating pendulum. The gear train design and the method to calculate the parameters and the pitch curves of the non-circular gears are presented.

A prototype is designed and built to validate that the presented method can balance a pendulum over an unlimited range of motion. Experimental results show a work reduction of 87 % compared to an unbalanced pendulum and the hysteresis in the mechanism is 36 %.
Dead-Beat Control of Walking for a Torso-Actuated Rimless Wheel Using an Event-Based, Discrete, Linear Controller
Authors: Bhounsule Pranav A. , Ameperosa Ezra , Miller Scott , Seay Kyle , Ulep Rico
Published: December 2016

In this paper, we present dead-beat control of a torso-actuated rimless wheel model. We compute the steady state walking gait using a Poincaré map. When disturbed, this walking gait takes a few steps to cancel the effect of the disturbance but our goal is to develop a faster response. To do this, we develop an event-based, linear, discrete controller designed to cancel the effect of the disturbance in a single step — a one-step dead-beat controller. The controller uses the measured deviation of the stance leg velocity at mid-stance to set the torso angle to get the wheel back to the limit cycle at the following step. We show that this linear controller can correct for a height disturbance up to 3% leg length. The same controller can be used to transition from one walking speed to another in a single step. We make the model-based controller insensitive to modeling errors by adding a small integral term allowing the robot to walk blindly on a 7° uphill incline and tolerate a 30% added mass. Finally, we report preliminary progress on a hardware prototype based on the model.
Assembly-Level Design for Additive Manufacturing: Issues and Benchmark
Authors: Yang Sheng , Tang Yunlong , Zhao Yaoyao Fiona
Published: December 2016

The emerging additive manufacturing (AM) technology works in a layer-wise fashion which makes it possible to manipulate material distribution and composition. The resulting effects are reflected on the potential of innovative shape design, consolidated assembly, optimized topology, and functionally graded material. These new characteristics force designers to rethink about how to make a better engineering design. However, existing design theory and methodology cannot take these potentials provided by AM into account. To fill this void, various design for additive manufacturing (DFAM) approaches are reported. Unfortunately, majority of them focused on part-level redesign without potential of being extended to assembly-level applications. In order to shed a light into this emerging field, an overview of current assembly-level DFAM is summarized in this paper. After that, existing issues including the absent analysis of AM’s impact on conceptual design, the lack of explicit functional analysis method, the shortage of decision-making support for part consolidation, the deficiency of functional reasoning approaches to generate AM-enabled features, and the scarcity of integrating manufacturing and assembly knowledge into design stage are analyzed and discussed. However, it seems that addressing these issues is such a large scope that collaborative efforts are in need from both design and manufacturing communities. Therefore, this paper serves as a call to action for the research community to establish a comprehensive assembly-level/ product-level DFAM method to realize product evolution. As an initial benchmark, authors propose a three-stage design methodology on the basis of the Systematic Design approach. In the presented framework, functional analysis, part consolidation, and structural optimization with process knowledge integration are much highlighted. Moreover, a simple redesign case study is exemplified to clarify existing issues and how the benchmark method works. In the end, this paper is wrapped up with future research.
Investigating the Effects of Design Choice and Application of Energy Technologies in Rural Developing Households Using an Integrated Systems Model
Authors: MacCarty Nordica A. , Bryden Kenneth Mark
Published: December 2016

Engineering system modeling and design tools are needed to help successfully provide appropriate and desirable energy technologies to the 2.7 billion people presently relying on inefficient and polluting solid fuels to meet their basic energy needs for cooking, heating, and lighting. To understand the impacts of technology design choices and applications, a previously-developed model was used to investigate the energy consumption and resulting environmental, economic, and social outcomes relative to the baseline situation for a rural village in Mali. Simulations were conducted to explore important considerations regarding potential energy technologies in terms of design choices such as usability, multi-functionality, cost, and durability; and application factors such as energy needs and fuel/device stacking, fuel supply, and the rebound effect. It was illustrated that the positive impacts of a new technology may be reduced significantly if the use of more polluting traditional devices must continue in parallel due to the auxiliary benefits offered by the three-stone fire. It was also shown that technologies must be provided at cost levels that offer outcomes more highly valued than investment costs in terms of payback period and income fraction in order to justify their cost to the user. And due to the realities of fuel and device stacking and the usability and suitability of different technologies to meet different energy needs, identification and disaggregation of the specific energy needs in a community are needed to select the most appropriate strategies to supply clean energy services and encourage their uptake by consumers.
Quantifying the Impact of Sustainable Product Design Decisions in the Early Design Phase Through Machine Learning
Authors: Wisthoff Addison , Ferrero Vincenzo , Huynh Tony , DuPont Bryony
Published: December 2016

As more companies and researchers become interested in understanding the relationship between product design decisions and eventual environmental impact, proposed methods have explored meeting this demand. However, there are currently limited methods available for use in the early design phase to help quantify the environmental impact of making design decisions. Current methods, primarily vetted Life Cycle Assessment (LCA) methods, require the designer to wait until later in the design phase, when a product’s design is more defined; alternatively, designers are resigned to relying on prior sustainable design experience and empirical knowledge. There is a clear need to develop methods that quantitatively inform designers of the environmental impact of design decisions during the early design phase (particularly during concept generation), as this allows for reexamination of decisions before they become costly or time-intensive to change. The current work builds on previous research involving the development of a search tree of sustainable design knowledge, which, applied during the early design phase, helps designers hone in on the impact of product design decisions. To assist in quantifying the impact of these design decisions, the current work explores the development of a weighting system associated with each potential design decision. The work presented in this paper aims to quantify the general environmental impact potential design decisions have on a consumer product, by using a multi-layer perceptron neural network with back propagation training — a method of machine learning — to relate the life-cycle assessment impact of 37 case study products to product attributes. By defining the relationship between LCA data and product attributes, designers in the early design phase will be more informed of which product attributes have the largest environmental impact, such that the designer can redesign the product to have reduce this impact.
Tunable Wave Dynamics in Origami-Based Mechanical Metamaterials
Authors: Yasuda Hiromi , Lee Mia , Yang Jinkyu
Published: December 2016

We investigate unique wave dynamics in origami-based mechanical metamaterials composed of volumetric 3D origami unit cells. Specifically, we assemble a chain of lattice structures, in which the Tachi-Miura Polyhedron (TMP) is employed as a building block. We conduct two types of theoretical/computational analysis on this origami-based system. One is the dynamic analysis on the TMP unit cell under harmonic excitations. We find that the system transits from linear to nonlinear regimes or vice versa, depending on the amplitude of the excitation and the initial configurations of the given geometry. This implies that the origami-based system exhibits intrinsic tun-ability of its dynamic behavior by altering these excitation and geometrical parameters. The other analysis is on a dispersion relationship of mechanical waves propagating through the lattice. We analyze a 1D chain of (i) all identical TMP unit cells and (ii) two different unit cells in an alternating arrangement. From this analysis, we show that the origami-based system can create tunable frequency band structures by changing geometrical parameters. By leveraging these unique, tunable wave dynamics, the origami-based mechanical systems have great potential to be used as novel engineering devices that are capable of handling vibrations and impact efficiently.
Improving Engineering Graphics Grading Using a Shape Similarity Algorithm: An Initial Investigation
Authors: Renu Rahul , Garland Anthony , Grigg Sarah , Minor John , Yasmin Nighat
Published: December 2016

Each year, over 700 students take the Engineering Graphics course taught within the General Engineering Program at Clemson University. A SCALE-UP (Student-Centered Activities for Large-Enrollment Undergraduate Programs) environment is utilized to provide a highly collaborative, hands-on classroom format with a primary emphasis on learning by guided inquiry and live demonstrations rather than by traditional lecturing. One of the goals of using this format is real-time assistance and rapid feedback.

In the spring term, each class day, 400 student submit a solid model file. This presents a challenge to returning feedback before the next class period. The current grading method consists of students submitting solid model files to a course management system and awarding credit for submissions matching the mass of the presented design. However, this method does not allow students to earn partial credit based on the relative accuracy of their model. To date, instructors have been unable to reward partial credit in an automated or timely manner.

The objective of this research is to evaluate the use of shape similarity algorithms to provide decision making support while grading solid models for this engineering graphics course. The proposed method of automated grading is to use a solid model similarity algorithm and the mass properties to assess the relative similarity of each submission to a correct solid model. The distribution of grades using the proposed method is compared to the existing method’s distribution. Use of the proposed method ensures that the results from this research can be applied to other engineering graphics courses, regardless of the solid modeling software used.
Probabilistic Modeling and Analysis of Fused Deposition Modeling Process Using Surrogate Models
Authors: Liu Yi , Wang Pingfeng
Published: December 2016

Various sources of uncertain parameters at multiple levels, from design steps to manufacturing processes, are often involved in composite structures. Probabilistic modeling and analysis of the composite structure and its manufacturing processes can provide underlying information to assess uncertainties and improve the quality of the developed composite structures. This paper presents a stochastic multi-level modeling framework considering material, structural, modeling parameters as well as the manufacturing process based on a surrogate model. An enhanced laminate theory is employed to determine the elastic constants of the composite materials considering imperfect bonding among filaments in the manufacturing process. To improve the computational efficiency in simulation-based reliability approach, the evaluation of the structure properties is approximated by employing surrogate models based upon the physics model. To apply the present framework, a case study with a composite laminate beam under three-point bending, which is made through fused deposition modeling, is conducted, and the case study results demonstrate the efficacy of the presented modeling scheme and analysis methodology.
Engineering Resilience Quantification and Design Implications: A Literature Survey
Authors: Yodo Nita , Wang Pingfeng
Published: December 2016

A resilient system is a system that possesses the ability to survive and recover from the likelihood damage of disruptive events or mishaps. The concept that incorporates resiliency into engineering practices is known as engineering resilience. To date, engineering resilience is still predominantly application-oriented. Despite an increased popularity of engineering resilience usage, the diversity of its application in various engineering sectors complicates the universal agreements on its quantification and measurement techniques. There is a pressing need to develop a universal framework, which standardize the modeling, assessment, and improvement of engineering resilience for a broader engineering discipline. This paper provides a literature survey of engineering resilience from the design perspective with the focuses on engineering resilience metrics and their design implications. The currently available engineering resilience quantification metrics are reviewed and summarized, the design implications towards the development of resilient engineering systems are discussed, and further the challenges of incorporating resilience into engineering design processes are evaluated. The presented study expects to serve as the building blocks towards developing a generally applicable engineering resilience quantification metrics that can be used for system design.
Product “In-Use” Context Identification Using Feature Learning Methods
Authors: Ghosh Dipanjan D. , Olewnik Andrew , Lewis Kemper
Published: December 2016

Usage context is considered a critical driving factor for customers’ product choices. In addition, the physical use of a product (i.e., user-product interaction) dictates a number of customer perceptions (e.g. level of comfort, ease-of-use or users’ physical fatigue). In the emerging Internet-of-Things (IoT), this work hypothesizes that it is possible to understand product usage while it is ‘in-use’ by capturing the user-product interaction data. Mining the data and understanding the comfort of the user adds a new dimension to the product design field. There has been tremendous progress in the field of data analytics, but the application in product design is still nascent. In this work, application of ‘feature learning’ methods for the identification of product usage context is demonstrated, where usage context is limited to the activity of the user. Two feature learning methods are applied for a walking activity classification using smartphone accelerometer data. Results are compared with feature-based machine learning algorithms (neural networks and support vector machines), and demonstrate the benefits of using the ‘feature learning’ methods over the feature based machine-learning algorithms.
Discussion and Analysis of Main Dynamic Balancing Methods for Robotic Manipulators
Authors: Zhang Dan , Wei Bin
Published: December 2016

Vibration reduction in robotic manufacturing industries has been a vital issue since the last decade. Some of the vibrations are caused by a dynamic unbalanced condition. The dynamic balancing solution has become one of the most effective ways to reduce vibration and improve overall accuracy of the system. In this paper, dynamic balancing methods and the development of robotic mechanisms are reviewed and analyzed in detail. Dynamic balancing methodology is generally divided into two main categories: balancing prior to kinematic synthesis and balancing after the design process. Each of the balancing methods in the above two categories are illustrated. The advantages and disadvantages of each method are presented and compared. This paper will provide an informative guideline for future research in the direction of dynamic balancing of robotic mechanisms.
Robust Design Optimization by Adaptive-Sparse Polynomial Dimensional Decomposition
Authors: Ren Xuchun , Rahman Sharif
Published: December 2016

This work proposes a new methodology for robust design optimization (RDO) of complex engineering systems. The method, capable of solving large-scale RDO problems, involves (1) an adaptive-sparse polynomial dimensional decomposition (AS-PDD) for stochastic moment analysis of a high-dimensional stochastic response, (2) a novel integration of score functions and AS-PDD for design sensitivity analysis, and (3) a multi-point design process, facilitating standard gradient-based optimization algorithms. Closed-form formulae are developed for first two moments and their design sensitivities. The method allow that both the stochastic moments and their design sensitivities can be concurrently determined from a single stochastic simulation or analysis. Precisely for this reason, the multi-point framework of the proposed method affords the ability of solving industrial-scale problems with large design spaces. The robust shape optimization of a three-hole bracket was accomplished, demonstrating the efficiency of the new method to solve industry-scale RDO problems.
Design and Experimental Analysis of Origami-Inspired Vibration Isolators With Quasi-Zero-Stiffness Characteristic
Authors: Ishida Sachiko , Suzuki Kohki , Shimosaka Haruo
Published: December 2016

We present a prototype vibration isolator whose design is inspired by origami-based foldable cylinders with torsional buckling patterns. The vibration isolator works as a nonlinear spring that has quasi-zero spring stiffness in a given frequency region, where it does not transmit vibration in theory. We evaluate the performance of the prototype vibration isolator through excitation experiments via the use of harmonic oscillations and seismic-wave simulations of the Tohoku-Pacific Ocean and Kobe earthquakes. The results indicate that the isolator with the current specification is able to suppress the transmission of vibrations with frequencies of over 6 Hz. The functionality and constraints of the isolator are also clarified.

It has been known that origami-based foldable cylinders with torsional buckling patterns provide bistable folding motions under given conditions. In a previous study, we proposed a vibration isolator utilizing the bistability characteristics and numerically confirmed the device’s validity as a vibration isolator. Here, we attempt prototyping the isolator with the use of versatile metallic components and experimentally evaluate the isolation performance.
Modeling Consideration Gives Strategic Design Insight for Addressing Diesel and Brand Perception
Authors: Erickson Michael , MacDonald Erin F. , Long Minhua
Published: December 2016

This paper explores consumer consideration and design response in the wake of a product scandal, namely the Volkswagen “clean diesel” scandal. It offers the novel contribution of designing for consideration, rather than final choice, with a linked market consideration and engineering model. The paper demonstrates how consideration modeling can be used to identify design strategy that capture lost consideration. A simulation study investigates three response design strategies: a design refresh by competitors; repricing by VW; and a new design by VW. The model used to investigate these scenarios includes data from a nation-wide survey conducted by Autolist that collected self-reported ratings of both VW and diesel consideration before and after the scandal. It also includes an engineering model that translates engineering variables (such as engine bore) into vehicle design attributes (such as fuel economy and rollover score). The case study finds that a design refresh by a competitor or a new vehicle design by VW can capture more consideration sets than a VW repricing strategy alone, suggesting the importance of coordinating both design and economic strategies. The approach demonstrates the usefulness of design-for-consideration as a strategic before/after scenario analysis tool in the wake of an event that triggers shifts consumers’ considerations.
Enabling Smart Manufacturing Technologies for Decision-Making Support
Authors: Helu Moneer , Libes Don , Lubell Joshua , Lyons Kevin , Morris K. C.
Published: December 2016

Smart manufacturing combines advanced manufacturing capabilities and digital technologies throughout the product lifecycle. These technologies can provide decision-making support to manufacturers through improved monitoring, analysis, modeling, and simulation that generate more and better intelligence about manufacturing systems. However, challenges and barriers have impeded the adoption of smart manufacturing technologies. To begin to address this need, this paper defines requirements for data-driven decision making in manufacturing based on a generalized description of decision making. Using these requirements, we then focus on identifying key barriers that prevent the development and use of data-driven decision making in industry as well as examples of technologies and standards that have the potential to overcome these barriers. The goal of this research is to promote a common understanding among the manufacturing community that can enable standardization efforts and innovation needed to continue adoption and use of smart manufacturing technologies.
Data-Driven Simulation for Fast Prediction of Pull-Up Process in Bottom-Up Stereo-Lithography
Authors: Wang Jun , Das Sonjoy , Zhou Chi , Rai Rahul
Published: December 2016

Developing cohesive finite element simulation models of the pull-up process in bottom-up stereo-lithography (SLA) system can significantly increase the reliability and through-put of the bottom-up SLA process. Pull-up process modeling investigates relation between motion profile and crack initialization and propagation during the separation process. However, finite element (FE) simulation of the pull-up process is computationally very expensive and time-consuming. This paper outlines a method to quickly predict the separation stress distribution based on 2D shape grid mapping and neural network. Sixteen cohesive FE models with various cross-section shapes form our database. Specific 2D shape grid mapping was utilized to describe each shape by generating a sorted binary vector. A backpropagation (BP) neural network was then trained using binary vectors, material properties, and FE simulated pull-up separation stress distribution. Given material properties, the trained model can then be used to predict the pull-up separation stress distribution of a new shape. The results demonstrate that the proposed data driven method can drastically reduce computing costs. The comparison between the predicted values by the data driven approach and simulated FE models verify the validity of the proposed method.
Homogenization of Mechanical Properties for Additively Manufactured Periodic Lattice Structures Considering Joint Stiffening Effects
Authors: Park Sang-in , Rosen David W.
Published: December 2016

This paper presents a homogenization approach for estimating the mechanical properties of periodic lattice structures; it is based on semi-rigid joint frame elements, and it takes into account joint stiffening effects. Geometrical degradation that arises from the additive manufacturing process is considered and integrated into a homogenization procedure that uses structural element parameters derived from a frame element with semi-rigid joints. The effective values of the structural parameters are calculated from a novel as-fabricated model describing an additively fabricated strut and are incorporated into proposed semi-rigid frame elements. The semi-rigid joint frame element is integrated into a discrete homogenization process. This paper reports the results of parametric studies that compare the effective structural parameters and the estimated mechanical properties to study the impacts of joints and geometric degradation due to additive manufacturing. The results of the proposed approach are compared with previous homogenization approaches, and show that the proposed method provides more accurate estimates.
Overcoming Challenges in the Design and Manufacturing of Small Scale Rocket Engines
Authors: Matthys Kory , Walsh Wyatt , Long Joshua , Wagner Drew , Powell Ian , Cox Michael , Piacenza Joseph
Published: December 2016

The once ubiquitous national space program, characterized by large-scale experiments, nearly gratuitous levels of funding, and unrivaled access to materials and talent, has given way to a multitude of smaller, decentralized entities. Furthermore, it is likely that a large market will soon exist for space tourism, suborbital passenger delivery, and other low payload missions. This trend has resulted in the potential for a substantial technological shift away from traditionally used large-scale rocket engines to smaller scale, reusable engines. A rocket that is liquid-fueled is ideal for this context, because liquid fueled engines are generally regarded as being safer than solid fuel engines, and unlike hybrid rockets, they can be refueled. However, the downsizing of liquid fueled rocket engines has not been thoroughly explored. Subsequently, there are many engineering challenges that have yet to be solved. Despite this difficulty, the vacuum of knowledge also presents an opportunity to pursue innovative designs and manufacturing techniques that are untenable for larger engines. This work seeks to overcome said obstacles and implement creative solutions to pursue small-scale rocket technology. Specifically addressed by this research is the design of the injector system and necessary considerations to facilitate manufacturing.
A New Algebraic Solution to Inverse Static Force Analysis of a Special Planar Three-Spring System
Authors: Zhang Ying , Liao Qizheng , Wei Shimin , Wei Feng , Li Duanling
Published: December 2016

In this paper, we present a new algebraic elimination algorithm for the inverse static force analysis of a special planar three-spring system. The system consists of three linear springs joined to the ground at the two fixed pivots and connected to the two moving pivots at the platform. When exerted by specified static force, the goal of inverse static analysis is to determine all the equilibrium configurations. First of all, a system of seven polynomial equations in seven variables is established based on the geometric constraint and static force balancing. Then, four basic constraint equations in four variables are obtained by variable substitution. Next, a 20 by 20 resultant matrix is reduced by means of three consecutive Sylvester elimination process. Finally, a 54th-degree univariate polynomial equation is directly derived without extraneous roots in the computer algebra system Mathematica 9.0. At last, a numerical example is given to verify the elimination procedure.
Design of Passive 3-PRR Planar Parallel Manipulators for Self-Alignment of Exoskeleton Axes
Authors: Ghosh Shramana , Gan Dongming
Published: December 2016

Self-alignment mechanisms for exoskeletons alleviate critical issues arising from misalignment between exoskeleton and human joints. In this paper we present a method for kinematic synthesis of a passive mechanism for aligning joint axes of exoskeletons with human anatomical joint axes. Planar parallel manipulators are known for their inherent stiffness and compactness; we propose a novel parallel manipulator design to achieve self-alignment. The base platform of the parallel manipulator is attached to the human arm and the moving platform is attached to the exoskeleton. Three PRR chains connect the base and moving platforms. An optimal design problem is formulated to find the smallest manipulator that spans the specified workspace, which represents the possible area of misalignment.
Analysis on Educating Mechanical Engineers Through Serious Games Using Pervasive Technologies
Authors: Baalsrud Hauge Jannicke Madeleine , Lim Theodore , Kalverkamp Matthias , Haase Florian , Bellotti Francesco
Published: December 2016

In the education of mechanical engineers alternative learning methods like serious games, simulations etc. have been used in past decades to better the learning outcomes. However, as digital technologies advance, so too does the quality of commercial game-based learning. This brings the expectation that while serious games are still considered as an experimental pedagogic vehicle, the learning experience among students and their experience of using serious games become heightened. This is a challenge for several educational games that though fully able to progress a learning goal, is deemed detached due to its dated user interface and inability to host the latest ICTs. This creates an unappealing aspect to the student and can also affect their motivation. This paper reports on the early efforts to analyze serious games from the perspective of learning and gaming mechanics and the virtual environment and systems that can be made pervasive. The intention is to re-furbish dated serious games that are highly relevant to educating mechanical engineers. The proposed concepts lie in the adoption of new pervasive technologies enabled by cyber-physical systems (CPS) and Internet of things (IoT) to modernize dated engineering serious games.
Computer-Aided Ethnography in Engineering Design
Authors: Dixon Adam , Liu Ying , Setchi Rossi
Published: December 2016

Modern upsurges of innovative technologies and sciences such as the internet of things, machine learning, cheap sensor technology and cloud computing have yielded new opportunities in the area of engineering design. This paper examines the state of the art of the fuzzy front end of engineering design in capturing customer and market information through ethnography and associated techniques. The reviewed range of technologies involve multimedia capture of ethnography, data analytics, as well as traditional researcher led approaches. Intelligent ethnography is presented as an expansion to customer analytics in the offline field, to capitalise on these developments. As a result of this study, market and design teams will better understand how to capture the voice of customer, design data and market data to push for ever more relevant products and technologies. Finally, a new application named inferred engineering has been identified as a fuzzy front end evidence based ideation technique.
Multi-Objective Optimization of Road Vehicle Passive Suspensions With Inerter
Authors: Ramakrishnan Kesavan , Yang Liunan , Ballo Federico Maria , Gobbi Massimiliano , Mastinu Giampiero
Published: December 2016

The influence of inerter on the performance of passive suspension systems is studied by comparing six different suspension architectures using a simplified quarter-car model. The suspension architectures can have one or two springs, damper, and inerter. Ride comfort, road holding, and working space are considered as the objective functions, while the suspension spring stiffness, damping ratio, and inerter equivalent mass are taken as the design variables for the multi-objective optimization. The Pareto-optimal solutions are computed and compared in the objective functions domain. The results confirm that specific inerter architectures provide advantages when all the design variables are varied. The inerter benefits are more evident in all the considered architectures, when the suspension spring stiffness is kept constant.
Reduced Order Modeling for Inverse Parameter Identification of Ti-5111 Friction Stir Welding
Authors: Iliopoulos Athanasios P. , Michopoulos John G. , Lambrakos Samuel
Published: December 2016

Forward and inverse modeling of the friction stir welding (FSW) process is an important endeavor, which can be used to optimize process parameters that can play a significant role on achieving specification requirements of manufactured parts. In this work a Reduced Order Modeling (ROM) approach is presented with the aim to reduce the forward step evaluation of an optimization loop that implements the solution of the relevant inverse problem. This is done in order to reduce the overall computational time required. The feasibility and efficiency of this approach is demonstrated through its implementation and the comparison between the full and the reduced order model implementations.
Nonlinearity of Finite-Amplitude Waves in Rectangular Containers
Authors: Daqaq Mohammed F. , Xu Yawen , Lacarbonara Walter
Published: December 2016

This paper investigates the two-dimensional nonlinear finite-amplitude sloshing dynamics of an irrotational, incompressible fluid in a rectangular container. In specific, the paper addresses the influence of surface tension represented by a coefficient, β, and the ratio between the fluid height and the container’s width, represented by h/L, on the nonlinear normal sloshing modes. To achieve this objective, we first study the influence of, β, and, h/L, on the modal frequencies and generate a map in the (h/L, β) parameters’ space to highlight regions of possible nonlinear internal resonances up to the fifth mode. The map is used to characterize the regions where a single uncoupled nonlinear mode is sufficient to capture the response of surface waves. For these regions, we study the influence of surface tension on the effective nonlinearity of the first four modes and illustrate its considerable influence on the softening/hardening behavior of the uncoupled nonlinear modes. Subsequently, we investigate the response of the sloshing waves near internal resonance of the two-to-one type. We show that, in the vicinity of these internal resonances, the steady-state sloshing response can either contain a contribution from the two interacting modes (coupled-mode response) or only the higher frequency mode (un-coupled high-frequency mode response). We show that the regions where the coupled-mode uniquely exists has a clear dependence on the surface tension.
Vehicle Motion Measurements Using Front Facing Camera and Digital Image Correlation
Authors: Botha Theunis R. , Els P. Schalk , Jacobson Bengt , Albinsson Anton
Published: December 2016

Modern active vehicle safety systems rely on certain vehicle motion states to function. ABS requires the vehicle longitudinal speed to calculate the tire slip. The vehicle speed is typically estimated using the speed of all the wheels and is therefore dependent on the slip states of all the wheels. Electronic stability programs can also make more informed decisions if the vehicle side-slip angle is known. Currently the side-slip angle is not measured on commercial vehicles due to the cost of the sensors. The side-slip angle can however be estimated using multiple onboard vehicle measurements. However, these estimation techniques require accurate sensors and large excitations to estimate accurately. The measurement of the vehicle motion is therefore crucial for modern vehicle safety systems. This paper proposes a method whereby all 6 vehicle velocities can be measured using inexpensive forward facing mono and stereo cameras utilizing Digital Image Correlation (DIC) algorithms.