Recent Submissions

  • Motion and Sash Height (MASH) alarms for efficient fume hood use 

    Kongoletos, Johnathan; Munden, Ethan; Ballew, Jennifer; Preston, Daniel J. (2021)
    Ventilation, including fume hoods, consumes 40–70% of the total energy used by modern laboratories. Energy-conscious fume hood usage—for example, closing the sash when a hood is unused—can significantly reduce energy expenditures due to ventilation. Prior approaches to promote such behaviors among lab users have primarily relied on passive feedback ...
  • A node-numbering-invariant directional length scale for simplex elements 

    Takizawa, Kenji; Ueda, Yuki; Tezduyar, Tayfun E. (2019)
    Variational multiscale methods, and their precursors, stabilized methods, have been very popular in flow computations in the past several decades. Stabilization parameters embedded in most of these methods play a significant role. The parameters almost always involve element length scales, most of the time in specific directions, such as the direction ...
  • A hierarchical classification of adolescent idiopathic scoliosis: Identifying the distinguishing features in 3D spinal deformities 

    Pasha, Saba; Hassanzadeh, Pedram; Ecker, Malcolm; Ho, Victor (2019)
    This study aimed to identify the differentiating parameters of the spinal curves’ 2D projections through a hierarchical classification of the 3D spinal curve in adolescent idiopathic scoliosis (AIS). A total number of 103 right thoracic left lumbar pre-operative AIS patients were included retrospectively and consecutively. A total number of 20 ...
  • Measurement and identification of the nonlinear dynamics of a jointed structure using full-field data; Part II - Nonlinear system identification 

    Jin, Mengshi; Kosova, Giancarlo; Cenedese, Mattia; Chen, Wei; Singh, Aryan; (2022)
    The dynamic responses of assembled structures are greatly affected by the mechanical joints, which are often the cause of nonlinear behavior. To better understand and, in the future, tailor the nonlinearities, accurate methods are needed to characterize the dynamic properties of jointed structures. In this paper, the nonlinear characteristics of a ...
  • Measurement and identification of the nonlinear dynamics of a jointed structure using full-field data, Part I: Measurement of nonlinear dynamics 

    Chen, Wei; Jana, Debasish; Singh, Aryan; Jin, Mengshi; Cenedese, Mattia; (2022)
    Jointed structures are ubiquitous constituents of engineering systems; however, their dynamic properties (e.g., natural frequencies and damping ratios) are challenging to identify correctly due to the complex, nonlinear nature of interfaces. This research seeks to extend the efficacy of traditional experimental methods for linear system identification ...
  • Heterogeneous material mapping methods for patient-specific finite element models of pelvic trabecular bone: A convergence study 

    Babazadeh Naseri, Ata; Dunbar, Nicholas J.; Baines, Andrew J.; Akin, John E.; Higgs III, C. Fred; (2021)
    Patient-specific finite element (FE) models of bone require the assignment of heterogeneous material properties extracted from the subject's computed tomography (CT) images. Though node-based (NB) and element-based (EB) material mapping methods (MMMs) have been proposed, the sensitivity and convergence of FE models to MMM for varying mesh sizes are ...
  • Myoelectric control and neuromusculoskeletal modeling: Complementary technologies for rehabilitation robotics 

    Berning, Jeffrey; Francisco, Gerard E.; Chang, Shuo-Hsiu; Fregly, Benjamin J.; O'Malley, Marcia K. (2021)
    Stroke and spinal cord injury (SCI) are a leading cause of disability in the United States, and researchers have pursued using robotic devices to aid rehabilitation efforts for resulting upper-extremity impairments. To date, however, robotic rehabilitation of the upper limb has produced only limited improvement in functional outcomes compared to ...
  • A quantitative assessment of the model form error of friction models across different interface representations for jointed structures 

    Porter, Justin H.; Balaji, Nidish Narayanaa; Little, Clayton R.; Brake, Matthew R.W. (2022)
    Hysteretic models are widely used to model frictional interactions in joints to recreate experimental behavior. However, it is unclear which models are best suited for fitting or predicting the responses of structures. The present study evaluates 26 friction model/interface representation combinations to quantify the model form error. A Quasi-Static ...
  • Lifetime Prediction Using a Tribology-Aware, Deep Learning-Based Digital Twin of Ball Bearing-Like Tribosystems in Oil and Gas 

    Desai, Prathamesh S.; Granja, Victoria; Higgs, C. Fred (2021)
    The recent decline in crude oil prices due to global competition and COVID-19-related demand issues has highlighted the need for the efficient operation of an oil and gas plant. One such avenue is accurate predictions about the remaining useful life (RUL) of components used in oil and gas plants. A tribosystem is comprised of the surfaces in relative ...
  • Strain Hardening From Elastic-Perfectly Plastic to Perfectly Elastic Indentation Single Asperity Contact 

    Ghaednia, Hamid; Mifflin, Gregory; Lunia, Priyansh; O'Neill, Eoghan O.; Brake, Matthew R. W. (2020)
    Indentation measurements are a crucial technique for measuring mechanical properties. Although several contact models have been developed to relate force-displacement measurements with the mechanical properties, they all consider simplifying assumptions, such as no strain hardening, which significantly affects the predictions. In this study, the ...
  • The Influence of Additively Manufactured Nonlinearities on the Dynamic Response of Assembled Structures 

    Shu, Hang; Smith, Scott A.; Brake, Matthew R.W.; Tribomechadynamics Laboratory (2020)
    Structural dynamic techniques have been proven accurate at predicting the vibrations of single parts (i.e., monolithic specimens), which are widely used in industrial applications. However, vibration analysis of such assemblies often exhibits high variability or nonrepeatability due to jointed interfaces. Inspired by advances in additive manufacturing ...
  • U-duct turbulent-flow computation with the ST-VMS method and isogeometric discretization 

    Aydinbakar, Levent; Takizawa, Kenji; Tezduyar, Tayfun E.; Matsuda, Daisaku (2021)
    The U-duct turbulent flow is a known benchmark problem with the computational challenges of high Reynolds number, high curvature and strong flow dependence on the inflow profile. We use this benchmark problem to test and evaluate the Space–Time Variational Multiscale (ST-VMS) method with ST isogeometric discretization. A fully-developed flow field ...
  • Space–time VMS isogeometric analysis of the Taylor–Couette flow 

    Aydinbakar, Levent; Takizawa, Kenji; Tezduyar, Tayfun E.; Kuraishi, Takashi (2021)
    The Taylor–Couette flow is a classical fluid mechanics problem that exhibits, depending on the Reynolds number, a range of flow patterns, with the interesting ones having small-scale structures, and sometimes even wavy nature. Accurate representation of these flow patterns in computational flow analysis requires methods that can, with a reasonable ...
  • Electrochemical Biosensors for Cytokine Profiling: Recent Advancements and Possibilities in the Near Future 

    Dutta, Nirmita; Lillehoj, Peter B.; Estrela, Pedro; Dutta, Gorachand (2021)
    Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory ...
  • In situ, real-time measurements of contact pressure internal to jointed interfaces during dynamic excitation of an assembled structure 

    Dreher, T.; Brake, M.R.W.; Seeger, B.; Krack, M. (2021)
    Despite the ubiquitousness of jointed structures, the nonlinear interfacial behavior within bolted joints is still an insufficiently studied and poorly understood environment. For the development of effective simulation approaches, a deeper understanding of the salient physical effects within the contact surface is needed. This work studies the ...
  • A linear-elasticity-based mesh moving method with no cycle-to-cycle accumulated distortion 

    Tonon, Patrícia; Sanches, Rodolfo André Kuche; Takizawa, Kenji; Tezduyar, Tayfun E. (2021)
    Good mesh moving methods are always part of what makes moving-mesh methods good in computation of flow problems with moving boundaries and interfaces, including fluid–structure interaction. Moving-mesh methods, such as the space–time (ST) and arbitrary Lagrangian–Eulerian (ALE) methods, enable mesh-resolution control near solid surfaces and thus ...
  • Lateral flow immunochromatographic assay on a single piece of paper 

    Jiang, Xue; Lillehoj, Peter B. (2021)
    Lateral flow immunochromatographic assays (LFIAs) are analytical devices used to detect the presence of one or more target analytes in a liquid sample. While LFIAs are one of the simplest and inexpensive types of immunoassays, they consist of multiple components (sample pad, conjugate pad, membrane, absorbent pad, backing card) and materials, requiring ...
  • How Well Do Commonly Used Co-contraction Indices Approximate Lower Limb Joint Stiffness Trends During Gait for Individuals Post-stroke? 

    Li, Geng; Shourijeh, Mohammad S.; Ao, Di; Patten, Carolynn; Fregly, Benjamin J.; (2021)
    Muscle co-contraction generates joint stiffness to improve stability and accuracy during limb movement but at the expense of higher energetic cost. However, quantification of joint stiffness is difficult using either experimental or computational means. In contrast, quantification of muscle co-contraction using an EMG-based Co-Contraction Index (CCI) ...
  • Evaluation of Synergy Extrapolation for Predicting Unmeasured Muscle Excitations from Measured Muscle Synergies 

    Ao, Di; Shourijeh, Mohammad S.; Patten, Carolynn; Fregly, Benjamin J.; Rice Computational Neuromechanics Lab (2020)
    Electromyography (EMG)-driven musculoskeletal modeling relies on high-quality measurements of muscle electrical activity to estimate muscle forces. However, a critical challenge for practical deployment of this approach is missing EMG data from muscles that contribute substantially to joint moments. This situation may arise due to either the inability ...
  • Musculoskeletal Model Personalization Affects Metabolic Cost Estimates for Walking 

    Arones, Marleny M.; Shourijeh, Mohammad S.; Patten, Carolynn; Fregly, Benjamin J. (2020)
    Assessment of metabolic cost as a metric for human performance has expanded across various fields within the scientific, clinical, and engineering communities. As an alternative to measuring metabolic cost experimentally, musculoskeletal models incorporating metabolic cost models have been developed. However, to utilize these models for practical ...

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