bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Evaluations for the Effects of Amplitude and Frequency of Vibration on the Friction of Coiled Tubing in Hydrocarbon Drilling Operations
Authors: Abdo Jamil , Al-Anqoudi Idris , Al-Sharji Hamed
Published: January 2015

In a hydrocarbon drilling operations, when an axial load is applied beyond a critical value the coiled tubing (CT) will buckle forming sinusoidal wave and with increasing the axial load the CT ultimately goes into a helical configuration. The higher number of contacts between the CT and the wellbore the more friction is introduced. Increasing the CT friction, due to increasing the area of contact with the wellbore, eventually leads to lock-up length beyond which the drilling cannot proceed further. Vibration is understood to be a well-known technique to reduce friction between contacting bodies in many engineering systems. An in-house experimental setup is developed to imitate the wellbore being drilled with the presence of vibrating facility that has the capability to vibrate the CT axially. The setup is employed to examine the effects of amplitude and frequency of vibration on the friction force, between the CT and the wellbore, and on the axial load transfer or the weight on bit (WOB) of the CT. Response surface methodology is used to produce a prediction model to determine the effects of various amplitudes and frequencies the WOB of the CT. The investigations have shown that both amplitude and frequency of vibration have positive effects on reducing friction force and increasing WOB. The actual and predicted optimal designs are also presented in this work.
An Application of Behavioral Game Theory in Equilibrium Analysis of Concurrent Product-Development Projects
Authors: Takai Shun
Published: January 2015

This paper analyzes design equilibrium in a concurrent product-development project using the results from behavioral game theory. In this study, a project consists of a team of three engineers who represent three product-development stages: product design, material selection, and process selection. Product-development tasks are globally distributed, and engineers are allowed to independently make product-development decisions (i.e., non-cooperative design). In addition, the engineers are evaluated according to the outcomes of both individual and team product-development tasks. When multiple design equilibria exist, but a dominant design equilibrium does not, the past behavioral-game-theory studies indicate that design equilibrium may be reached under two conditions. In the first condition, one engineer is allowed to announce his/her intended alternative even though he/she does not need to actually choose the announced alternative. In the second condition, one engineer is selected to make his/her choice first but the other engineers do not know what that choice is. Sensitivity analysis indicates that a wide variety of design equilibria will emerge depending on how engineers are evaluated.
Simulation and Experimental Validation of Tapered Roller Bearing Vibration Induced by Geometrical Imperfection on Cup Raceway
Authors: Li Desheng , Kang Young Sup
Published: January 2015

A three dimensional non-linear vibration model of tapered roller bearings was developed based on an in-house dynamic bearing model (DBM), which simulates the motion of bearing components and their interactions using Hertzian contact, traction, and hydrodynamic/ elastohydrodynamic lubrication models. The vibration model can simulate bearings with distributed and localized geometrical imperfections on their cup raceways, cone raceways, and roller bodies. This paper focuses on the influence of localized cup raceway imperfections on bearing vibration. Three levels of localized defects were intentionally created on cup raceways and quantified using a surface profile gauge. The quantified defects on actual test bearings were used as inputs to the vibration model. The corresponding test bearings were evaluated with a high-precision bearing vibration test machine. Two different bearing designs were used in the study. The simulation and test data were analyzed and compared, and it was found that the simulation results agreed well with the test data.
Efficient Global Optimization Reliability Analysis (EGORA) for Time-Dependent Limit-State Functions
Authors: Hu Zhen , Du Xiaoping
Published: January 2015

If a limit-state function involves time, the associated reliability is defined within a period of time. The extreme value of the limit-state function is needed to calculate the time-dependent reliability, and the extreme value is usually highly nonlinear with respect to random input variables and may follow a multimodal distribution. For this reason, a surrogate model of the extreme response along with Monte Carlo simulation is usually employed. The objective of this work is to develop a new method, called the Efficient Global Optimization Reliability Analysis (EGORA), to efficiently build the surrogate model. EGORA is based on the Efficient Global Optimization (EGO) method. Different from the current method that generates training points for random variables and time independently, EGORA draws training points for the two types of input variables simultaneously and therefore accounts for their interaction effects. The other improvement is that EGORA only focuses on high accuracy at or near the limit state. With the two improvements, the new method can effectively reduce the number of training points. Once the surrogate model of the extreme response is available, Monte Carlo simulation is applied to calculate the time-dependent reliability. Good accuracy and efficiency of EGORA are demonstrated by three examples.
A Software Tool for Simulating Motions and Loading in Planar Tensegrity Structures
Authors: Nelson Carl A.
Published: January 2015

Tensegrity structures are unique in the sense that they tend to be overconstrained as mechanisms, yet they can be mobile due to the elastic nature of their tensile elements. The ability to easily visualize these motion properties would help designers to create new and useful tensegrity mechanisms. In this paper, a simple and interactive computational tool with a graphical user interface is presented for visualizing loading and displacements in tensegrity structures. This tool can also be extended for use with traditional static structures, including both determinate and indeterminate structures, as well as mechanisms.
Evaluation of Complementarity Techniques for Minimal Coordinate Contact Dynamics
Authors: Mylapilli Harshavardhan , Jain Abhinandan
Published: January 2015

In this article, the non-smooth contact dynamics of multi-body systems is formulated as a complementarity problem. Minimal coordinates operational space formulation is used to derive the dynamics equations of motion. Depending on the approach used for modeling Coulomb’s friction, the complementarity problem can be posed either as a linear or a nonlinear problem. Both formulations are studied in this paper. An exact modeling of the friction cone leads to a nonlinear complementarity problem (NCP) formulation whereas a polyhedral approximation of the friction cone results in a linear complementarity problem (LCP) formulation. These complementarity problems are further recast as non-smooth unconstrained optimization problems, which are solved by employing a class of Levenberg-Marquardt algorithms. The necessary theory detailing these techniques is discussed and five schemes are implemented to solve contact dynamics problems. A simple test case of a sphere moving on a plane surface is used to validate these schemes, while a twelve-link pendulum example is chosen to compare the speed and accuracy of the schemes presented in this paper.
A Simulation Method to Estimate the Time-Varying Failure Rate of Dynamic Systems
Authors: Wang Zhonglai , Zhang Xiaoqiang , Huang Hong-Zhong , Mourelatos Zissimos P.
Published: January 2015

The failure rate of dynamic systems with random parameters is time-varying even for linear systems excited by a stationary random input. In this paper, we propose a simulation-based method to estimate this time-varying failure rate. The input and output stochastic processes are discretized using a small time step to calculate the trajectories of the output stochastic process accurately through simulation. The planning horizon (time of interest) is then partitioned into a series of longer correlated time intervals and the Saddlepoint approximation (SPA) is employed to estimate the distribution of maximum response and thus obtain the probability of failure in each time interval. Using the same simulated trajectories with SPA, a time-dependent copula is built to provide the correlation between the response in each time interval and the response up to that time interval. The time-varying failure rate is finally estimated at each discrete time, using the probability of failure in each time interval and the correlation information from the estimated copula. The effectiveness of the proposed method is illustrated with a vehicle vibration example.
A Race Motorcycle Frame: Advanced Design
Authors: Ballo Federico , Gobbi Massimiliano , Massera Marta , Mastinu Giampiero
Published: January 2015

The concept and the embodiment design of a frame for a race motorcycle is addressed. The motorcycle is designed for the Moto3 World Championship. The aim is to develop a frame that could be eventually produced by die casting.

Given the basic geometry of the motorcycle and the engine dimensions, a multi-body model is derived by Modelica. The model is able to simulate the dynamic behaviour of the motorcycle in the two most critical conditions of use, namely braking and passing over a cleat. A comparison with experimental data has allowed the validation of the model.

By means of Optistruct, an optimized structure for the frame is proposed and compared to the one derived by an experienced designer. A technique is proposed for the computation of stresses in the frame that exploits, in an integrated manner, FEM and multi-body modeling. A fatigue analysis aimed at assessing the life of the frame is performed.

The combination of the most advanced modeling tools has enabled the design of a very light and stiff frame, additionally a process has been derived for future development of optimised motorcycle frames.
Design for Pedestrian Protection
Authors: Fürst Alexander , Inkermann David , Vietor Thomas
Published: January 2015

Pedestrians are among the most vulnerable participants in current city traffic. While in the past original equipment manufacturers (OEMs, in meanings of carmakers) mainly focused on passenger safety, nowadays strict legislation requirements call for the development of more effective pedestrian safety concepts. Considerations for constructive and technological road safety measures generally take place in a company-specific product development process, but mainly in phases, that do not allow for innovative products in terms of new solutions. Thus, the importance of early development phases as well as design process models, such as Pahl and Beitz, will be described here. Also the significance of the development design cases will be handled, as they can mainly influence the innovation degree of the resulting products. In the end an approach will be introduced, of how an analysis of product models regarding their possibilities for adequate evaluation can help, to support a safety-related development process by integrating suitable design methods and tools.
Gauging Military Vehicle Mobility Through Many-Body Dynamics Simulation
Authors: Melanz Daniel , Mazhar Hammad , Negrut Dan
Published: January 2015

This paper describes a modeling, simulation, and visualization framework aimed at enabling physics-based analysis of ground vehicle mobility. This framework, called Chrono, has been built to leverage parallel computing both on distributed and shared memory architectures. Chrono is both modular and extensible. Modularity stems from the design decision to build vertical applications whose goal is to reduce the end-to-end time from vision-to-model-to-solution-to-visualization for a targeted application field. The extensibility is a consequence of the design of the foundation modules, which can be enhanced with new features that benefit all the vertical applications. Two factors motivated the development of Chrono. First, there is a manifest need of modeling approaches and simulation tools to support mobility analysis on deformable terrain. Second, the hardware available today has improved to a point where the amount of sheer computer power, the memory size, and the available software stack (productivity tools and programming languages) support computing on a scale that allows integrating highly accurate vehicle dynamics and physics-based terramechanics models. Although commercial software is available nowadays for simulating vehicle and tire models that operate on paved roads; deformable terrain models that complement the fidelity of present day vehicle and tire models have been lacking due to the complexity of soil behavior. This paper demonstrates Chrono’s ability to handle these difficult mobility situations through several simulations, including: (i) urban operations, (ii) muddy terrain operations, (iii) gravel slope operations, and (iv) river fording.
Effect of Foot Location on Human Running Prediction
Authors: Chung Hyun-Joon , Bhatt Rajan , Xiang Yujiang , Arora Jasbir S. , Abdel-Malek Karim
Published: January 2015

Human running is simulated in this work by using a skeletal digital human model with 55 degrees of freedom (DOFs). A predictive dynamics method is used to formulate the running problem, and normal running is formulated as a symmetric and cyclic motion. The dynamic effort and impulse are used as the performance measure, and the upper body yawing moment is also included in the performance measure. The joint angle profiles and joint torque profiles are calculated for the full-body human model, and the ground reaction force is determined. The effect of foot location on the running motion prediction are simulated and studied.
A Method to Add Energy to Running Gait: PogoSuit
Authors: Kerestes Jason , Sugar Thomas G. , Flaven Thierry , Holgate Matthew , Ramachandran Ragesh K.
Published: January 2015

The human body is a mass spring system that oscillates up and down while running. We add energy to the running gait by oscillating a secondary mass in phase with the motion. A phase oscillator adds a bounded amount of energy to the limit cycle to make it easier to run. In an anti-phase oscillator, energy in the gait cycle is reduced and it is harder to run.
Visualization Tool for Interpreting User Needs From User-Generated Content via Text Mining and Classification
Authors: Stone Thomas , Choi Seung-Kyum
Published: January 2015

The amount of user-generated content related to consumer products continues to grow as users increasingly take advantage of forums, product review sites, and social media platforms. The content is a promising source of insight into users’ needs and experiences. However, the challenge remains as to how concise and useful insights can be extracted from large quantities of unstructured data. We propose a visualization tool which allows designers to quickly and intuitively sift through large amounts of user-generated content and derive useful insights regarding users’ perceptions of product features. The tool leverages machine learning algorithms to automate labor-intensive portions of the process, and no manual labeling is required by the designer. Language processing techniques are arranged in a novel way to guide the designer in selecting the appropriate inputs, and multidimensional scaling enables presentation of the results in concise 2D plots. To demonstrate the efficacy of the tool, a case study is performed on action cameras. Product reviews from Amazon.com are analyzed as the user-generated content. Results from the case study show that the tool is helpful in condensing large amounts of user-generated content into useful insights, such as the key differentiations that users perceive among similar products.
The Three Dimensional Gradient Deficient Beam Element (BEAM9) Using the Absolute Nodal Coordinate Formulation
Authors: Mohamed Abdel-Nasser A. , Liu Jeff
Published: January 2015

In this investigation, a three dimensional gradient deficient beam element (BEAM9) using the absolute nodal coordinate formulation (ANCF) is introduced. This element has nine coordinates per node, this includes the position vector and the two gradient vectors rx and ry. Like most of the ANCF elements, this element has constant mass matrix and zero centrifugal and Coriolis inertia forces. The plane strain elastic force model and the elastic line approach are two elastic force models presented in this paper in order to simulate the element internal resistance. Both models support resistance to the general bending and twist moments. The possibilities of employing nonlinear material models will be discussed in future work. Furthermore, the proposed element has the advantage of easy integration over general cross section area that is not easy to perform using the fully parameterized ANCF beam element (BEAM12). Comparing to the ANCF cable element (BEAM6), the proposed element can resist general bending and twist loads. Moreover, shear deformations in the xy plane due to shear force and in the yz plane due to twist moment are considered with the gradient deficient beam element proposed in this work. However, no shear deformations are considered with the ANCF cable element. Comparing to the fully parameterized ANCF beam element, the gradient deficient beam element (BEAM9) avoids some locking issues, shows better computational efficiency and offers better convergency characteristics. Numerical examples are presented in order to validate the proposed gradient deficient beam element and to compare with other ANCF beam elements.
Enhanced Full-State Estimation and Dynamic-Model-Based Prediction for Road-Vehicles
Authors: Alamdari Aliakbar , Sovizi Javad , Krovi Venkat N.
Published: January 2015

In this paper, we address the enhanced state estimation and prediction system for automobile applications by fusing relatively low-cost and noisy Inertial Navigation System (INS) sensing with Global Positioning System (GPS) measurements. An unscented Kalman filter is used to merge multi-rate measurements from GPS and INS sensors together with a high-fidelity vehicle-dynamics model for state-predictions. The high-fidelity motion model (including suspension-effects) for the vehicle motion trajectory on uneven terrain is captured by a 20-state system of nonlinear differential equations. Computer simulation results illustrate the effectiveness of sensor-fusion (building upon the merger of an inexpensive INS sensing with GPS based measurements) to accurately estimate the full system-state. The relative ease of implementation, accuracy and predictive performance with low-cost sensing will facilitate its use in various electronic control and safety-systems, such as Electronic Stability Program, Anti-lock Brake Systems, and the Lateral Dynamic Stability Control.
Toward a Value-Driven Design Approach for Complex Engineered Systems Using Trade Space Exploration Tools
Authors: Miller Simon W. , Simpson Timothy W. , Yukish Michael A. , Stump Gary , Mesmer Bryan L. , Tibor Elliott B. , Bloebaum Christina L. , Winer Eliot H.
Published: January 2015

Design decision-making involves trade-offs between many design variables and attributes, which can be difficult to model and capture in complex engineered systems. To choose the best design, the decision-maker is often required to analyze many different combinations of these variables and attributes and process the information internally. Trade Space Exploration (TSE) tools, including interactive and multi-dimensional data visualization, can be used to aid in this process and provide designers with a means to make better decisions, particularly during the design of complex engineered systems. In this paper, we investigate the use of TSE tools to support decision-makers using a Value-Driven Design (VDD) approach for complex engineered systems. A VDD approach necessitates a rethinking of trade space exploration. In this paper, we investigate the different uses of trade space exploration in a VDD context. We map a traditional TSE process into a value-based trade environment to provide greater decision support to a design team during complex systems design. The research leverages existing TSE paradigms and multi-dimensional data visualization tools to identify optimal designs using a value function for a system. The feasibility of using these TSE tools to help formulate value functions is also explored. A satellite design example is used to demonstrate the differences between a VDD approach to design complex engineered systems and a multi-objective approach to capture the Pareto frontier. Ongoing and future work is also discussed.
Homokinetic Shaft-Coupling Mechanisms via Double Schoenflies-Motion Generators
Authors: Lee Chung-Ching , Hervé Jacques M.
Published: January 2015

The paper begins with introducing the 5-dimensional (5D) double Schoenflies-motion (X-X motion) set employing the group product of two 4D X-motion subgroups of displacements. Two families of primitive X-X motion generators are briefly outlined. Then, the geometric constraints for homokinetic transmission via Lie-group-algebraic properties of the displacement set are established. After that, using the described mechanical generators of X-X motion as the basic building cell, we geometrically generate two major families of homokinetic shaft-coupling mechanisms characterized by a subchain with a mechanical generator of 5D X-X motion set of displacement. The obtained constant-velocity shaft couplings (CVSC) are isoconstrained linkages with two parallel shaft axes, which will be less sensitive to manufacture errors. In addition, by means of the reordering method for displacement group compositions, more CVSC mechanisms can be further obtained. The simple or special findings stemming from the proposed general architectures are presented for the potential applications too.
Resilience Modeling and Quantification for Design of Complex Engineered Systems Using Bayesian Networks
Authors: Hosseini Seyedmohsen , Yodo Nita , Wang Pingfeng
Published: January 2015

The concept of engineering resilience has received prevalent attention from academia as well as industry because it contributes a new means of thinking about how to withstand against disruptions and recover properly from them. Although the concept of resilience was scholarly explored in diverse disciplines, there are only few which focus on how to quantitatively measure the engineering resilience. This paper is dedicated to explore the gap between quantitative and qualitative assessment of engineering resilience in the domain of design of complex engineered systems. A conceptual framework is first proposed for the modeling of engineering resilience, and then Bayesian network is employed as a quantitative tool for the assessment and analysis of engineering resilience for complex systems. A case study related to electric motor supply chain is employed to demonstrate the proposed approach. The proposed resilience quantification and analysis approach using Bayesian networks would empower system designers to have a better grasp of the weakness and strength of their own systems against system disruptions induced by adverse failure events.
Design of Truss-Like Cellular Structures Using Relative Density Mapping Method
Authors: Alzahrani Mahmoud A. , Choi Seung-Kyum , Rosen David W.
Published: January 2015

The recent advances in additive manufacturing technology enable the development of complicated structural systems. For instance, meso-scale lattice structures (MSLS) have significant potential to be applied in light-weight applications. Determining the appropriate designs for these truss-like cellular structures can be a challenging task due to their geometric complexities and prohibitive computational costs in design processes. In this research, a new design method, namely, relative density mapping (RDM) method is developed by utilizing the material density information obtained from topology optimization results in continuum structures. The proposed method utilizes by-product information from topology optimization results to design cellular structures after the topology optimization has been conducted to decide the layout of the structure. Since the proposed method does not require additional optimization or black-box simulation procedures, it can drastically reduce computational costs in the design process of the cellular structures. Moreover, the developed method can be applicable to any complicated shapes of cellular structures. The efficacy of the developed method is compared to existing methods. The presented results demonstrate significant potential for designing truss-like cellular structures based on the by-product information from the topology optimization procedure.
Inverse Reliability Analysis for Approximated Second-Order Reliability Method Using Hessian Update
Authors: Lim Jongmin , Lee Byungchai , Lee Ikjin
Published: January 2015

According to order of approximation, there are two types of analytical reliability analysis methods; first-order reliability method and second-order reliability method. Even though FORM gives acceptable accuracy and good efficiency for mildly nonlinear performance functions, SORM is required in order to accurately estimate the probability of failure of highly nonlinear functions due to its large curvature. Despite its necessity, SORM is not commonly used because the calculation of the Hessian is required. To resolve the heavy computational cost in SORM due to the Hessian calculation, a quasi-Newton approach to approximate the Hessian is introduced in this study instead of calculating the Hessian directly. The proposed SORM with the approximated Hessian requires computations only used in FORM leading to very efficient and accurate reliability analysis. The proposed SORM also utilizes the generalized chi-squared distribution in order to achieve better accuracy. Furthermore, an SORM-based inverse reliability method is proposed in this study as well. A reliability index corresponding to the target probability of failure is updated using the proposed SORM. Two approaches in terms of finding more accurate most probable point using the updated reliability index are proposed and compared with existing methods through numerical study. The numerical study results show that the proposed SORM achieves efficiency of FORM and accuracy of SORM.
Constraint-Based Design and Analysis of a Compliant Parallel Mechanism Using SMA-Spring Actuators
Authors: Qiu C. , Zhang K. , Dai Jian S.
Published: January 2015

This paper presents a novel compliant parallel mechanism that utilizes shape-memory-alloy (SMA) spring based actuators. By employing SMA coil springs, the traditional line constraint that resists translation along its axis but no other forms of motions is transformed into a linear actuator that can generate deflection along its axis, which leads to the design of SMA-spring linear actuators. In accordance with this SMA actuator, an constraint-based approach in the framework of screw theory is utilized to synthesize the constraint and actuation space of parallel mechanisms, and a novel 4 DOF parallel platform is developed based on this analytical approach. A physical prototype is manufactured by employing the SMA-spring actuators, and its mobility and workspace are verified with both finite element simulation and experiment observations. The results illustrate this parallel mechanism has a large workspace in all desired mobility configurations. The presented work on the parallel platform demonstrates the efficiency of the constraint-based approach in determining the layout of actuation systems, also the developed SMA actuators pave a new way for applying the SMA technique in the future development of compliant parallel mechanisms and robotics.
Projective Jacobi and Gauss-Seidel on the GPU for Non-Smooth Multi-Body Systems
Authors: Nützi Gabriel , Schweizer Adrian , Möller Michael , Glocker Christoph
Published: January 2015

Large-scale contact problems with impacts and Coulomb friction arise in the simulation of rigid body dynamics treated within the non-smooth contact dynamics approach using set-valued force and impact laws. In this paper the parallelization of two popular numerical methods for solving such contact problems on the GPU, being the projected over-relaxed Jacobi (JOR Prox) and projected Gauss-Seidel iteration (SOR Prox), is studied in detail. Performance tests for the parallel JOR and SOR Prox iterations are conducted and a speedup factor of up to 16, depending on the problem size, can be achieved compared to a sequential implementation. This work forms the stepping stone to the simulation of granular media on a computer cluster.
Continuum Robotic Tail Loading Analysis for Mobile Robot Stabilization and Maneuvering
Authors: Rone William S. , Ben-Tzvi Pinhas
Published: January 2015

This paper presents the analysis of a continuum robot for use as a robotic tail. The tail is envisioned for use on-board a mobile robot to provide a means separate from the locomotion mechanism (e.g., legs or wheels) to generate external forces and moments to stabilize and/or maneuver the robot. A Cosserat rod model is used to simulate the mechanics of the tail. In these analyses, a prescribed tail configuration (for static analysis) or trajectory (for dynamic analysis) is applied, and the governing equations are used to calculate the loading at the base of the tail, which will be transmitted to the mobile robot. This analysis studies the impact of both trajectory and design factors on the resulting loading profiles. Trajectory factors considered include the mode shape, speed, bending magnitude and bending plane angle. Design factors considered for a fixed mass tail include segment length(s) and mass distribution. This research will ultimately assist future continuum robotic tail designs.
Concept, Design, and Application of Sleeve Muscle Actuator
Authors: Zheng Hao , Shen Xiangrong
Published: January 2015

Sleeve muscle is a new class of pneumatic muscle actuator that provides significant performance improvement and new design characteristics in comparison with the traditional pneumatic muscle. Inspired by the force-generating mechanism of traditional pneumatic muscle, the sleeve muscle incorporates a unique insert structure to eliminate the loss of extension force capacity due to the air pressure applied to the moving end connector. Two types of sleeve muscle are presented in this paper, including a single-acting type that enables the integration of the actuator with the load bearing structure, and a double-acting type that provides a unique capability of bi-directional actuation. The designs of these sleeve muscle actuators are discussed, along with their potential applications in bio-robotic systems.
Mining End-of-Life Materials Suitable for Material Resynthesis and Discovering New Application Domains
Authors: Doll Kristopher , Tucker Conrad S.
Published: January 2015

The United States generates more than 250 million tons of municipal solid waste (trash/garbage), with only 34% being recycled. In the broader global environment, the problem of waste management is becoming increasingly relevant, demanding innovative solutions. Traditional End-of-Life (EOL) approaches to managing waste include recycle, reuse, remanufacture and disposal. Recently, resynthesis was proposed as an alternative to traditional EOL options that combines multiple products to create a new product distinct from its parent assemblies. Resynthesis employs data mining and natural language processing algorithms to quantify assembly/subassembly combinations suitable for new product combinations. However, existing resynthesis methodologies proposed in the design community have been limited to exploring subassembly combinations, failing to explore potential combinations on a materials level. The authors of this paper propose a material resynthesis methodology that combines the materials of multiple EOL products using conventional manufacturing processes that generate candidate resynthesized materials that satisfy the needs of existing domains/applications. Appropriate applications for a resynthesized material are discovered by comparing the properties of the new material to the functional requirements of application classes which are found using clustering and latent semantic analysis. In the course of this paper, the authors present a case study that demonstrates the feasibility of the proposed material resynthesis methodology in the construction materials domain.
Development of an Ontology for the Automatic Selection of Control Valves
Authors: Bai Jing , Kai Yang
Published: January 2015

The control valve selection is a much-needed breakthrough in the development of major technological equipment. The automation of the control valve selection process is still a challenge. Addressing this issue, an ontology model for automatic selection of control valves is proposed and a methodology for building the model is suggested, which fully characterizes structured and unstructured knowledge for automatic selection, and effectively captures the semantic association between application requirements and product features in the selection process. The experimental results demonstrate the effectiveness of this method for the automatic selection of control valves.
Vehicle Dynamics Models for Onboard Motion Planning
Authors: Mukherjee Rudranarayan , Howard Thomas , Myint Steven , Chang Johnny , Craft Jack
Published: January 2015

Offline multibody dynamics based modeling and simulation of vehicle dynamics has been pursued with varying levels of success for more than two decades. This has been used in design, controls, training, and other technical and programmatic objectives. Over the last decade, autonomous vehicle dynamics has become an important area of research. This has resulted in a growing need for onboard vehicle model that works with the vehicle controller and path planner. Typically, kinematic models have largely been used for these objectives. Use of dynamics models for onboard motion planning is a relatively new topic of research with only a handful of prior work. In this paper we report our attempts at addressing the need for onboard vehicle dynamics models for motion planning in relatively fast autonomous mobility scenarios. We present the idea of using adaptive motion models that trade fidelity and cost of simulation to enable a motion planner to select an adequate model. Towards this, we present representative simulation results that demonstrate the need for adaptivity. We then present some technical challenges with onboard vehicle models and our attempts at addressing these challenges. Finally, we present some results that compare raw vehicle data with model predictive results.
Hands-On Online? An Investigation of Experiential Design Education With Online Resources
Authors: Ramos Joshua D. , Wallace David R.
Published: January 2015

Online education is becoming more prevalent in every field, especially with the advent of MOOCs and initiatives such as Coursera, Edx, MITx, Khan Academy and more. Product design education involves open-ended problem solving and prototyping with physical materials, so it presents a number of interesting challenges in an online educational setting.

This paper describes an initial study to better understand the value proposition of offering hands-on product design education using different delivery methods, ranging from hands-on residential to fully online, and combinations in-between. A series of two-day workshops were used to teach students typical introductory product design coursework including opportunity identification and early-stage prototyping. Students attended one workshop session that was taught with one of three content delivery types: traditional (n = 9), online (n = 9), or hybrid (n = 8). Each student worked individually to identify a product opportunity and produce a preliminary prototype. The performance of the students was compared to elucidate any differences based on workshop delivery method.

Based on the comparison of student work, as evaluated by academic product design experts, there were no statistically significant differences in performance between groups. This result suggests that all delivery methods have potential for successfully transferring knowledge to students. Furthermore, this preliminary evidence warrants more detailed investigations of the effects of delivery method on product design education. Interesting observations regarding workshop attendance identify motivation to complete courses as a point of interest in both residential and online settings. A number of insights gained and possible directions are discussed.
Engineering Recoverability: A New Indicator of Design for Engineering Resilience
Authors: Li Junxuan , Xi Zhimin
Published: January 2015

Design of engineering resilient systems is an emerging research field. The contribution of this paper is to i) define engineering resilience on the basis of various resilience concepts in different fields; ii) propose the engineering recoverability as a new component in the framework of designing engineering resilient systems; and iii) introduce a general mathematical formulation to quantify the engineering resilience. One case study of a CNC machining system is used to demonstrate the value of designing engineering resilient systems.
On 1:2 Internal Resonances in In-Plane Vibrations of Electrostrictive Plates
Authors: Tripathi Astitva , Bajaj Anil K.
Published: January 2015

Electrostrictive polymers are popular materials being employed in fabrication of high-strain actuators for use in new generation micro- and nano-scale devices along with applications such as artificial muscles. In this work, possibility of 1:2 internal resonances in in-plane vibrations of appropriately designed electrostrictive plates is investigated. The polymer is assumed to have mechanical response similar to that of a Mooney Rivlin material and the induced strain having a quadratic dependence on the applied external electric field. A Finite Element Method (FEM) formulation is used to develop mode shapes of a structure whose lowest two natural frequencies have been brought close to the ratio of 1:2. Using the mode shapes thus obtained, a more complete Lagrangian formulation is used to develop a nonlinear two-mode model of the electrostrictive plate structure. Application of a harmonic electric field results in in-plane parametric oscillations of the structure. The nonlinear response of the structure is developed using averaging on the two-mode model. The structure exhibits 1:2 internal resonance due to the large amplitude vibrations through the route of parametric excitation. The effects of material constitutive parameters on the nonlinear response are investigated.
Impact of Requirements Elicitation Activity on Idea Generation: A Designer Study
Authors: Joshi Shraddha , Summers Joshua D.
Published: January 2015

This paper presents the findings from an empirical designer study conducted with senior design students to understand the impact of requirement elicitation activity on idea generation. The participants were divided in three groups. The experiment conditions were (1) requirements elicitation (given only problem statement), (2) partial elicitation (given problem and five requirements) and (3) no elicitation (given problem and ten requirements). Participants in the first two conditions were challenged with eliciting requirements first. All participants were also asked to generate solutions. Comparing the requirements addressed in the solutions generated by the participants, it is found that the group that was not primed with the task of eliciting requirements performed better in terms of addressing requirements when compared to other two groups. These findings lead to the inference in conceptual design stage that allowing the students to elicit requirements does not have significant potential benefits while addressing the requirements.
Design of a Compliant Monolithic Internally Statically Balanced Four-Bar Mechanism
Authors: Berntsen Luc , Gosenshuis Daan H. , Herder Just L.
Published: January 2015

Instigated by the need to statically balance compliant mechanisms, this paper presents a compliant internally static balanced monolithic four-bar linkage which can be used as generic building block in any compliant mechanism. The pivots of the four-bar are made compliant by the use of initially curved leaf springs. The balancing energy is provided by two pre-loaded opposing cantilever leaf springs that follow a circular path imposed by the input link in a range of forty degrees. The monolithic four-bar and its balancing mechanism are dimensioned by means of an analytical model (decoupled segments), optimized with a FE-analysis (coupled), and validated with a prototype and accompanying experiment. FEA shows a peak moment reduction of 95% (elastic material, working range: 40°), and the experiment of a lasercut 10 mm thick PMMA (visco-elastic material) prototype shows a peak moment reduction of 63% (working range: 36°) up to 88% (working range: 20°).
An Omnidirectional, Direct Singularity Drive System and its Inverse Kinematic Model
Authors: Reyer Julie A. , West Matthew T. , Jonnavittula Praveen K. , Costello Christopher T. , Boirum Curtis
Published: January 2015

This paper presents an omnidirectional drive system. The design presented here involves a spinning hemispherical wheel mounted on a gimbal. The wheel operates at its singularity point when in the “neutral” or static position. As the gimbal is tilted, the wheel provides a thrust vector to the vehicle. The tilt determines the effective radius of the wheel, which in turn determines the amount of power that can be transmitted for motion. The paper presents the design and kinematic and inverse kinematics analysis of a singularity drive mechanism.

Vehicles can have single or multiple singularity drive mechanisms to achieve increasing levels of maneuverability. From a control standpoint, each singularity drive is kinematically decoupled from other drives on the same vehicle. Vehicles with one, two and three singularity drive mechanisms are introduced and some experimental results are presented.
Iteration Complexity of the Alternating Direction Method of Multipliers for Quasi-Separable Problems in Multi-Disciplinary Design Optimization
Authors: Quan Ning , Kim Harrison
Published: January 2015

The Alternating Direction Method of Multipliers (ADMM) is a distributed algorithm suitable for quasi-separable problems in Multi-disciplinary Design Optimization. Previous authors have studied the convergence and complexity of the ADMM algorithm by treating it as an instance of the proximal point algorithm. In this paper, those previous results are extended to an alternate form of the ADMM algorithm applied to the quasi-separable problem. Secondly, a dynamic penalty parameter updating heuristic for the ADMM algorithm is introduced and compared against a previously proposed updating heuristic. The proposed updating heuristic was tested on a distributed linear model fitting example and performed favorably against the other heuristic and the fixed penalty parameter scheme.
A Modular Product Design Approach With Key Components Consideration to Improve Sustainability
Authors: Ma Junfeng , Okudan Kremer Gül E.
Published: January 2015

Modular product design (MPD) has attracted significant attention. The concept of sustainability has also received attention in view of the intensifying demands concerning environmental issues. Because the way a product or system is modularized can have implications on its sustainability, investigating MPD and sustainability jointly is important. To this intended joint investigation, we add the concept of a product’s key components. Mostly, product competitiveness depends strongly on a few key components; thus, we should logically design products with a concentrated consideration of their key components. However, to the best of our knowledge, only scant research addresses key components. Developing an optimal MPD method, which incorporates key components specification, is the primary motivation for this research. In this paper, we provide a sustainable modular product design approach. A graph-based clustering algorithm is offered to cluster components into modules. A module structure sustainability index (MSSI) is used to find an optimal sustainability module structure. A coffee maker case study is used to illustrate the proposed methodology.
Designettes: New Approaches to Multidisciplinary Engineering Design Education
Authors: Telenko Cassandra , Camburn Bradley , Hölttä-Otto Katja , Wood Kristin , Otto Kevin
Published: January 2015

Teaching of design and other fundamental topics in engineering is often isolated to dedicated courses. Thus, an opportunity is missed to foster a culture of engineering design and multidisciplinary problem solving throughout the curriculum. Designettes, defined as brief, vignette-like design challenges, exploit opportunities to integrate design learning experiences in class, across courses, across terms, and across disciplines. When courses join together in a designette, a multidisciplinary learning activity occurs, demonstrating how different subjects are integrated and applied to open-ended problems and grand challenges. Designettes help foster a culture of design, and enables the introduction of multidisciplinary design challenges across all core courses in each semester. These challenges combine problem clarification, concept generation and prototyping with subject content from curricula such as biology, thermodynamics, differential equations, and software with controls. This paper investigates the use of single and multidisciplinary designettes at SUTD. From pre- and post-surveys of junior college students, designettes were found to increase students’ awareness of applications and learning of content. From 321 third-semester students across six cohorts, designettes were found to increase students’ self-perceptions of their ability to solve multidisciplinary problems.
Analysis of Rollover Shape and Energy Storage and Return in Cantilever Beam-Type Prosthetic Feet
Authors: Olesnavage Kathryn M. , Winter Amos G.
Published: January 2015

This paper presents an analysis of the rollover shape and energy storage and return in a prosthetic foot made from a compliant cantilevered beam. The rollover shape of a prosthetic foot is defined as the path of the center of pressure along the bottom of the foot during stance phase of gait, from heel strike to toe off. This path is rotated into the reference frame of the ankle-knee segment of the leg, which is held fixed. In order to achieve correct limb loading and gait kinematics, it is important that a prosthetic foot both mimic the physiological rollover shape and maximize energy storage and return.

The majority of prosthetic feet available on the market are cantilever beam-type feet that emulate ankle dorsiflexion through beam bending. In this study, we show analytically that a prosthetic foot consisting of a beam with constant or monotonically decreasing cross-section cannot replicate physiological rollover shape; the foot is either too stiff when the ground reaction force (GRF) acts near the ankle, or too compliant when the GRF acts near the toe. A rigid constraint is required to prevent the foot from over-deflecting.

Using finite element analysis (FEA), we investigated how closely a cantilever beam with constrained maximum deflection could mimic physiological rollover shape and energy storage/return during stance phase. A constrained beam with constant cross-section is able to replicate physiological rollover shape with R2 = 0.86. The ratio of the strain energy stored and returned by the beam compared to the ideal energy storage and return is 0.504. This paper determines that there is a trade off between rollover shape and energy storage and return in cantilever beam-type prosthetic feet. The method and results presented in this paper demonstrate a useful tool in early stage prosthetic foot design that can be used to predict the rollover shape and energy storage of any type of prosthetic foot.