bluuebunny/crossref_metadata_2025_split huggingface dataset:
Introduction of Local Resonators to a Nonlinear Metamaterial With Topological Features
Authors: Malla Arun , LeGrande Joshua , Bukhari Mohammad , Barry Oumar 
Published: November 2023

Abstract
Metamaterials have been shown to benefit from the addition of local resonators, nonlinear elements, or topological properties, gaining features such as additional bandgaps and localized vibration modes. However, there is currently no work in the literature that examines a metamaterial system including all three elements. In this work, we model a 1-dimensional metamaterial lattice as a spring-mass chain with coupled local resonators. Quasiperiodic modulation in the nonlinear connecting springs is utilized to achieve topological features. For comparison, a similar system without local resonators is also modeled. Both analytical and numerical methods are used to study this system. The infinite chain response of the proposed system is solved through the perturbation method of multiple scales. This analytical solution is compared to the finite chain response, estimated using the method of harmonic balance and solved numerically. The resulting band structures and mode shapes are used to study the effects of quasiperiodic parameters and excitation amplitude on the system behavior both with and without the presence of local resonators. Specifically, the impact of local resonators on topological features such as edge modes is established, demonstrating the appearance of a trivial bandgap and multiple localized edge states for both main cells and local resonators.
On How a Self-Organizing System Produces Collective Behavior
Authors: Cao Jinhui , Ming Zhenjun , Allen Janet K. , Mistree Farrokh 
Published: November 2023

Abstract
In this paper we address the following question:
How can the designers of self-organizing systems use the relationships among relevant parameters to quantitatively characterize how a self-organizing system produces the collective behavior process, to better control and design a self-organizing system?
A self-organizing system has advantages in performing dangerous and exploratory tasks that are not suitable for humans. However, it is often difficult for designers to design self-organizing systems, because, in an environment with dynamic complexity, the process of how self-organizing systems behave collectively is unknown. To address this difficulty, we propose a method to quantitatively represent environmental complexity as well as the system behavior, and study the relationship between them so as to gain insights into how a self-organizing system produces collective behavior. In this paper, we identify four collective behavior patterns that a self-organizing system produces when the environment complexity changes, namely, initialing pattern, adjusting behavior, stabilizing pattern, and restarting pattern. We illustrate the efficacy of our method using a box-pushing problem. Our focus is on describing the method rather than the results.
Air Shield Design for Preventing Inhalation on Turbofan-Engines of Passenger-Jets
Authors: Li Yunchen , Wang Jun 
Published: November 2023

Abstract
Due to the recent frequent inhalation accident of turbofan engines on passenger jet planes, this paper designs a type of protection equipment that prevents it. We utilize the high-speed airflow generated by the outer duct of the high bypass ratio turbofan engine to protect the intake port of the large passenger aircraft with high-speed airflow, thereby greatly reducing the damage caused by the inhalation of the bird by the engine. In this paper, we analyze the working conditions when the equipment installs on a high bypass ratio turbofan engine, demonstrate the rationality of the system design, describe the design structure of the scheme in detail, and select the suitable gas source available for this scheme based on the structure diagram of GE-nX-1B74 turbofan engine. According to the parameters of the engine, the length of the GasTube was calculated, and the structure of the equipment was theoretically analyzed. Then, we performed a hydrodynamic analysis of the air and its jet in the pipe system. We use SolidWorks to model the GasTube, fan rotor, low-pressure compressor components, adapter, TubeFlower, high-pressure compressor, turbine block, and the simplified model of the engine nacelle and assemble them. A kinematics simulation was carried out. The 3D model is then subjected to force and airflow trajectory analysis using SolidWorks and Fluent. The 3D model is improved based on the simulation results. To more holistically evaluate the performance, we have simulated the design in the hardest work condition (i.e.. landing) of jet planes. Based on the theoretical and finite element analyses, suggestions for designing the aircraft engine protection equipment are proposed. The revised opinions are proposed and demonstrated in four aspects theoretically.
Design for Additive Manufacturing of Pneumatic Soft Robotics via a Large-Scale, High-Viscosity Vat Photopolymerization Process
Authors: Carbonell Roxana , Song Hongtao , Seepersad Carolyn , Crawford Richard 
Published: November 2023

Abstract
This research describes the design for additive manufacturing (AM) of a pneumatic soft robotic actuator that is uniquely enabled by a novel vat photopolymerization (VPP) AM process. Specifically, the device is a PneuNet style bending mechanism that is designed specifically for a high-viscosity, large-scale VPP AM system. This novel system is capable of fabricating high performance elastomeric materials, such as polydimethylsiloxane (PDMS) loaded with fumed silica nanoparticles or other fillers that result in viscosities too high to be printed with most existing VPP processes. Herein, a tough double network PDMS (DN-PDMS) is designed for printing pneumatic actuators. The mechanical properties of the DN-PDMS, along with the geometric resolution of resulting features, are characterized through experiments, and the results are used to guide the design process of the pneumatic actuator. The results show that the broad design space accessible through the high-viscosity VPP process corresponds with the target geometry identified in this research (determined by maximum bending angle). This design would be challenging or impossible to manufacture using other means; however, this VPP process enables printing of high viscosity materials, large overhangs, internal features, and a fully enclosed hollow structure. Results show that altering the chamber shape and incorporating internal structures leads to a 29.8% improvement in bending angle when compared with the original PneuNet actuator geometry simulated with the same material and pressurization.
An Invariant Representation of Coupler Curves Using a Variational Autoencoder: Application to Path Synthesis of Four-Bar Mechanisms
Authors: Nurizada Anar , Purwar Anurag 
Published: November 2023

Abstract
This paper focuses on the representation and synthesis of coupler curves of planar mechanisms using a deep neural network. While the path synthesis of planar mechanisms is not a new problem, the effective representation of coupler curves in the context of neural networks has not been fully explored. This study compares four commonly used features or representations of four-bar coupler curves: Fourier descriptors, wavelets, point coordinates, and images. The results demonstrate that these diverse representations can be unified using a generative AI framework called Variational Autoencoder (VAE). This study shows that a VAE can provide a standalone representation of a coupler curve, regardless of the input representation, and that the compact latent dimensions of the VAE can be used to describe coupler curves of four-bar linkages. Additionally, a new approach that utilizes a VAE in conjunction with a fully connected neural network to generate dimensional parameters of four-bar linkage mechanisms is proposed. This research presents a novel opportunity for automated conceptual design of mechanisms for robots and machines.
Performance Investigation of Fluid-Lubricated Thrust Bearings With Varying Textured Pad Surfaces Using Computational Fluid Dynamics
Authors: Yildiz Saltuk , Untaroiu Alexandrina 
Published: November 2023

Abstract
It is known that surface texturing provides enhanced mechanical and thermal behavior in the application of journal/thrust bearings and seals. This work presents an examination of parallel sector-pad thrust bearings consisting of twelve pads with textured surfaces in terms of load carrying capacity, friction torque and thermal performance. In this respect, the influence of different texturing patterns on the thrust bearing performance are presented and studied through 3D computational fluid dynamics (CFD) simulations based on the governing equations of incompressible lubricant, and these simulations are conducted in ANSYS-CFX. The previous studies commonly find optimum pattern geometry by keeping each pattern geometry the same such as only square and only elliptical. Unlike existing research studies, the use of varying dimple patterns which are the combinations of commonly used dimple geometries such as circular-elliptical, circular-square, and elliptical-square is investigated to demonstrate the performance of textured pads with varying pattern geometries. The simulation results are verified through experimental data provided in the literature. The CFD simulation results of varying patterned pads are compared with existing ones that are single patterned optimal designs. This study carries out optimal selection of varying dimple patterns that provides an insight for further optimization efforts on surface textured bearing and seals.
Understanding the State of Sanitation in India Through Qualitative Methods and a Septic Tank Sensing Device
Authors: Naik Monisha , Cotera Rivera Pablo , Garad Meghraj , Patil Digvijay P. , Rao Bakul , Bilton Amy M. 
Published: November 2023

Abstract
Worldwide, 3.6 billion people lack access to safely managed sanitation. India bears the brunt of this statistic, with over 395 million citizens lacking access today. Currently, Phase 2 of the Clean India Mission program focuses on connecting septic tanks to treatment facilities. However, according to previous studies, households only empty their septic tanks once they become completely full. A septic tank can only function properly until it is at approximately 70% of its capacity, and it is recommended that tanks should be emptied every 3 to 5 years. The authors hypothesize that a device to detect when a septic tank should be emptied could encourage households to empty their tanks on time. To gain a better understanding of how such a device would fit into the broader sanitation chain and the requirements of this device, a field study encompassing interviews, questionnaires, and septic tank data collection was conducted in three municipalities along the Warna River in Maharashtra, India. The results of the study reveal that the proposed device should only be introduced once a municipality has access to a functional fecal sludge treatment facility. Once a treatment plant has been built, depending on the municipality, different stakeholders need to be engaged in the device’s installation. Finally, the proposed device should detect a septic tank’s hydraulic retention time rather than the number of years since it was last emptied. This device will enable the Indian government to successfully implement Phase 2 of the Clean India Mission by alerting households to empty their tanks.
Design Space Enumerations for Pneumatically Actuated Soft Continuum Manipulators
Authors: Ripperger Evan , Krishnan Girish 
Published: November 2023

Abstract
Pneumatically actuated soft continuum manipulators (SCMs) are constructed by combining several extending or contracting fiber reinforced elastomeric enclosure (FREE) actuators in series, parallel and a combination thereof. While it is well known that architectures with serial combinations of FREEs yield large workspace and dexterity, they suffer from design and control complexity, increased number of valves and inertia. Recent advances in exploring the FREE design space has demonstrated using parallel combinations of dissimilar FREEs (bending and rotating) to improve workspace and dexterity. This paper presents a comprehensive investigation of SCM design architectures by enumerating possibilities of serial and parallel combinations of similar and dissimilar FREEs. A novel dexterity metric is proposed to enable objective comparison of different SCM designs based on shape similarity and end-effector tangent. Given a fixed resource of control inputs (actuator and valve inputs), the paper systematically selects the best architecture of the SCM (serial, parallel, similar or dissimilar FREE) that maximizes dexterity and workspace. It is seen that optimal designs are heavily dependent on the context of the application, which may change how these manipulators are deployed. The paper presents two practical design applications that demonstrate the usefulness of the enumeration framework. While in general, serial design combinations using symmetric bending actuators result in larger workspace and dexterity, some architectures with asymmetric combinations of FREEs may see similar levels of dexterity and workspace.
Empathic Ability Vs. User Satisfaction: Evaluating the Role of Preference Accuracy in Engineering Design
Authors: Johnson Erin , Letting Cynthia , Soria Zurita Nicolás F. , Menold Jessica 
Published: November 2023

Abstract
Prior work has identified the importance of empathy and the effect on design outcomes such as increased quality, originality, and usability. The measurement of empathy in the context of design, however, remains a pervasive issue. While several studies have proposed interventions, tools or methods to enhance designers’ empathy, it remains unclear how managers or designers can practically measure empathic abilities. Many of the existing methods are either incredibly time-consuming and thus not feasible in design practice or are not grounded in design work, making the translation and interpretation of instruments or surveys challenging. To address this gap, we study preference accuracy as a measure of empathic ability, and investigate its relationship with design outcomes, specifically user satisfaction. We review a case study implementing this method; fourteen participants were recruited and randomly paired with a partner. Individuals were tasked with designing a chair to meet their partner’s needs. Each participant interviewed their partner and completed two preference assessments: one detailing their own design preferences, and one detailing their perceptions of their partner’s design preferences. To calculate preference accuracy, the preference assessments for each participant were compared. Results from this study suggest preference accuracy may not be linked with user satisfaction, but may be a useful tool to differentiate empathic abilities across a population of designers.
Design Interviews Conducted by Intra- and Intercultural Teams: A Case Study on Dialysis in Zimbabwe
Authors: Grover Micki , Lauff Carlye A. , Ndhlovu Chiratidzo , Wright Natasha C. 
Published: November 2023

Abstract
In global development engineering, semi-structured, direct-dialogue interviews are often recommended in order to generate a deep understanding of stakeholders’ needs and to create products that meet those needs. In this study, interviews were used to explore the existing dialysis treatment program for end-stage kidney disease in Zimbabwe. This study has two aims: (i) to understand the dialysis service model and limits to its expansion, and (ii) to examine the impact of the cultural background of the interviewing team on interview outcomes.
Virtual training on exploratory interviewing was developed and administered to 12 undergraduate students living in the United States, Uganda, and Zimbabwe. Six teams, each having either an intercultural or intracultural composition conducted field interviews (n = 18) with Zimbabwean dialysis professionals to better understand the existing service model associated with hemodialysis (HD) and peritoneal dialysis (PD) treatment modalities. Interviews were coded in NVivo to develop an overall service model map including relevant people, props, and processes. Key limitations to expanding PD programs include: lack of clean water sources, no in-country dialysate production, insufficient financial resources, limited nursing staff, and difficulty in tracking medical information during home-based treatment, among others.
The service model map was additionally used to quantify the number of codes uncovered in individual interviews. Intercultural pairs produced a higher proportion of top scoring interviews than did the intracultural pairs. The small sample size, however, results in only an early indication of potentially replicable findings. The work represents a potential methodology for further research in this space.
A Customizable and Responsive Mechanism for a Chair to Assist During All Phases of Stand-To-Sit and Sit-To-Stand Maneuvers
Authors: Jhunjhunwala Sanchit , Kumar R Manoj , K. L. Chandrashekhara , Patil Sanjay , J. Kiran , Shaikh Ahmad , Ananthasuresh G. K. 
Published: November 2023

Abstract
Most of the assistive chairs do not provide support during the body-extension and stabilization phases of sit-to-stand maneuver because they only pivot about a horizontal axis. And there is limited scope for customization to individual’s needs. To address this, we present a mechanism that combines a compliant hinge mechanism with a linkage that includes a gas-spring. The compliant hinge mechanism uses open-circular cross-section shells that bend and twist to provide customized torque-angle characteristics with negative stiffness and bistability features. By adding a linkage with a gas-spring, the mechanism in this work is designed such that it provides the necessary support right from the intent to rise until the last phase of stabilizing in the standing position. Similar full support is provided for the stand-to-sit maneuver. Furthermore, the mechanism is responsive entirely by virtue of the compliant hinge mechanism and the gas-spring, and without using any sensors or external actuation. This completely mechanical device with two degrees of freedom allows the users to control the trajectory of the hip joint to their comfort and ability. Additionally, the envelope of trajectories of the seat that slides vertically and rotates about a horizontal axis can be mass-customized to ergonomic parameters of the population. We present the concept, customization features, kinetoelastic analysis, prototyping, and preliminary testing. We illustrate the efficacy of the mechanism through EMG data.
The Impact of Additive Manufacturing Constraints and Design Objectives on Structural Topology Optimization
Authors: Dangal Babin , Jung Sangjin 
Published: November 2023

Abstract
To analyze the impact of different objective functions and additive manufacturing (AM) constraints on structural topology optimization, it is necessary to perform an in-depth comparative study. This analysis should consider specific structural design factors, such as compliance, volume, or stress minimization, and assess their effects on the topology optimization for AM. In addition, the inclusion of AM constraints can have a significant influence on various aspects, including optimal part geometry, part volume, support structure volume, and structural performance. Thus, it is essential to examine and compare these factors to determine the optimal part design for AM. This study focuses on comparing topology optimization results obtained using compliance, stress, or multi-objective minimization, with and without AM constraints. The comparative analysis is conducted in the study, utilizing three structural design examples: cantilever beam, bridge-shaped structure, and L-shaped beam. The comparison results provide insights into the effects of build orientation, AM constraints such as overhang, and different design objectives on the structural topology optimization for AM.
Lifting Task Stability Evaluation Based on Balanced State Basins of a Humanoid Robot
Authors: Song Hyunjong , Peng William Z. , Kim Joo H. 
Published: November 2023

Abstract
Stability evaluation is a vital aspect of successful balance control and design for humanoid robots. While balance stability has been extensively explored for push recovery during legged locomotion tasks in response to perturbations, less effort has been devoted toward developing a similar understanding for lifting tasks. Lifting involves unique interactions between the robot and lifted object, whose mass can significantly alter the mass distribution of the loaded robot and the upper extremities, which are typically ignored in legged robot balance. In this study, the balance stability of a humanoid robot during a lifting task is evaluated with a partition-based approach in the augmented center-of-mass-state space. The balanced state boundary is computed through an optimization-based method that incorporates the loaded robot’s whole-body system properties, such as kinematic and actuation limits, with full-order nonlinear system dynamics in the sagittal plane subject to foot-ground contact interactions and lifting task requirements. The boundaries are constructed for different combinations of object masses and lifting trajectories obtained with a zero-moment point constraint-based pattern generator. Trends in the boundaries and comparisons among them are used to identify the effect of different loading conditions and task parameters on balance stability due to kinematic and actuation limits, linear and angular momenta regulation, and mass distribution.
Multiphysics-Informed Machine Learning for Battery Design and Health Monitoring
Authors: Bansal Parth , Li Yumeng 
Published: November 2023

Abstract
Current Lithium-ion battery (LIBs) designs are nearing the end of their performance capabilities. As the application and demand on these LIBs are growing continuously, there is also a need for continuous innovation both in the area of battery design and the area of battery state of health (SoH) monitoring. Using a silicon (Si) anode instead of a traditionally used graphite electrode allows an increase in the performance of existing LIBs. However, this increased performance comes at the cost of large stresses that develop in the anode as a result of large volumetric changes due to the unique alloying mechanism of the Lithium (Li) into the Si during the battery cycling. These volumetric stresses cause the development of cracks within the Si anode and delamination of the anode from the substrate, which leads to the capacity loss in the battery along with the growth of solid-electrolyte interface (SEI) on the exposed surfaces of the anode. In this study, we develop a physics-informed machine learning (PIML) model to monitor the SoH of the battery based on the output of these coupled failure modes of Si. 3D finite element (FE) models are built to explore how the large volumetric changes cause cracking and delamination in Si and how the SEI growth on the resultant exposed interfaces leads to the degradation of the battery. The outputs of these FE simulations will finally be used to train multiple Gaussian process regression (GPR) models, which combine together to estimate the SoH of the battery under the interactive effects of the studied failure modes. From the results of the study, it is evident that the developed PIML model which uses the output of LIB FE models, which include coupled failure modes, can be used to efficiently (using only 11.4% of charging time) estimate the SoH of the battery with reasonable accuracy (3.04% error).