Now showing items 1-20 of 143

    • A Ball and Beam Module for a Haptic Paddle Education Platform 

      Rose, Chad G.; Bucki, Nathan; O’Malley, Marcia K. (2017)
      Single degree of freedom force-feedback mechatronic devices, often called haptic paddles, are used in university curriculum as well as massive open online courses (MOOCs). While devices differ based on the goals of a given course, broadly speaking they provide hands-on learning for students studying mechatronics and dynamics. We introduce the third ...
    • A cable-based series elastic actuator with conduit sensor for wearable exoskeletons 

      Blumenschein, Laura H.; McDonald, Craig G.; O’Malley, Marcia K. (2017)
      There is currently a scarcity of wearable robotic devices that can practically provide physical assistance in a range of real world activities. Soft wearable exoskeletons, or exosuits, have the potential to be more portable and less restrictive than their rigid counterparts. In this paper, we present the design of an actuation system that has been ...
    • A Comprehensive Set of Impact Data for Common Aerospace Metals 

      Brake, M.R.W.; Reu, P.L.; Aragon, D.S. (2017)
      The results of two sets of impact experiments are reported within. To assist with model development using the impact data reported, the materials are mechanically characterized using a series of standard experiments. The first set of impact data comes from a series of coefficient of restitution (COR) experiments, in which a 2 m long pendulum is used ...
    • A computational framework for simultaneous estimation of muscle and joint contact forces and body motion using optimization and surrogate modeling 

      Eskinazi, Ilan; Fregly, Benjamin J. (2018)
      Concurrent estimation of muscle activations, joint contact forces, and joint kinematics by means of gradient-based optimization of musculoskeletal models is hindered by computationally expensive and non-smooth joint contact and muscle wrapping algorithms. We present a framework that simultaneously speeds up computation and removes sources of ...
    • A finite element model for magnetohydrodynamic squeeze-film flows 

      Wagner, Jordan R.; Higgs, C. Fred III (2018)
      A computational model is developed to analyze magnetohydrodynamic (MHD) squeeze-film flows featuring an electrically conducting fluid subjected to imposed magnetic and electric fields. The model is based on the so-called MHD Reynolds equation for squeeze-films—an extension of the classical hydrodynamic Reynolds equation. A complete derivation of the ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 perspective on climate model hierarchies 

      Jeevanjee, Nadir; Hassanzadeh, Pedram; Hill, Spencer; Sheshadri, Aditi (2017)
      To understand Earth's climate, climate modelers employ a hierarchy of climate models spanning a wide spectrum of complexity and comprehensiveness. This essay, inspired by the World Climate Research Programme's recent “Model Hierarchies Workshop,” attempts to survey and synthesize some of the current thinking on climate model hierarchies, especially ...
    • A predictive model of the temperature-dependent inactivation of coronaviruses 

      Yap, Te Faye; Liu, Zhen; Shveda, Rachel A.; Preston, Daniel J. (2020)
      The COVID-19 pandemic has stressed healthcare systems and supply lines, forcing medical doctors to risk infection by decontaminating and reusing single-use personal protective equipment. The uncertain future of the pandemic is compounded by limited data on the ability of the responsible virus, SARS-CoV-2, to survive across various climates, preventing ...
    • 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 ...
    • A reduced Iwan model that includes pinning for bolted joint mechanics 

      Brake, M.R.W. (2017)
      Bolted joints are prevalent in most assembled structures; however, predictive models for their behavior do not exist. Calibrated models, such as the Iwan model, are able to predict the response of a jointed structure over a range of excitations once calibrated at a nominal load. The Iwan model, though, is not widely adopted due to the high computational ...
    • A Review of Damping Models for Structures With Mechanical Joints 

      Mathis, Allen T.; Balaji, Nidish N.; Kuether, Robert J.; Brink, Adam R.; Brake, Matthew R.W.; (2020)
      In a standard design practice, it is often necessary to assemble engineered structures from individually manufactured parts. Ideally, the assembled system should perform as if the connections between the components were perfect, that is, as if the system were a single monolithic piece. However, the fasteners used in those connections, such as mechanical ...
    • A Review of Intent Detection, Arbitration, and Communication Aspects of Shared Control for Physical Human–Robot Interaction 

      Losey, Dylan P.; McDonald, Craig G.; Battaglia, Edoardo; O’Malley, Marcia K. (2018)
      As robotic devices are applied to problems beyond traditional manufacturing and industrial settings, we find that interaction between robots and humans, especially physical interaction, has become a fast developing field. Consider the application of robotics in healthcare, where we find telerobotic devices in the operating room facilitating dexterous ...
    • Alumoxane/ferroxane nanoparticles for the removal of viral pathogens: the importance of surface functionality to nanoparticle activity 

      (2012)
      A bi-functional nano-composite coating has been created on a porous Nomex fabric support as a trap for aspirated virus contaminated water. Nomex fabric was successively dip-coated in solutions containing cysteic acid functionalized alumina (alumoxane) nanoparticles and cysteic acid functionalized iron oxide (ferroxane) nanoparticles to form a ...
    • An exploration of grip force regulation with a low-impedance myoelectric prosthesis featuring referred haptic feedback 

      Brown, Jeremy D.; Paek, Andrew; Syed, Mashaal; O'Malley, Marcia K.; Shewokis, Patricia A.; (2015)
      Background: Haptic display technologies are well suited to relay proprioceptive, force, and contact cues from a prosthetic terminal device back to the residual limb and thereby reduce reliance on visual feedback. The ease with which an amputee interprets these haptic cues, however, likely depends on whether their dynamic signal behavior corresponds ...
    • An analytical method for analyzing symmetry-breaking bifurcation and period-doubling bifurcation 

      (2014)
      A new modification of homotopy analysis method (HAM) is proposed in this paper. The auxiliary differential operator is specifically chosen so that more than one secular term must be eliminated. The proposed method can capture asymmetric and period-2 solutions with satisfactory accuracy and hence can be used to predict symmetry-breaking and period-doubling ...
    • Aorta zero-stress state modeling with T-spline discretization 

      Sasaki, Takafumi; Takizawa, Kenji; Tezduyar, Tayfun E. (2018)
      The image-based arterial geometries used in patient-specific arterial fluid–structure interaction (FSI) computations, such as aorta FSI computations, do not come from the zero-stress state (ZSS) of the artery. We propose a method for estimating the ZSS required in the computations. Our estimate is based on T-spline discretization of the arterial wall ...
    • Assessing Wrist Movement With Robotic Devices 

      Rose, Chad G.; Pezent, Evan; Kann, Claudia K.; Deshpande, Ashish D.; O'Malley, Marcia K. (2018)
      Robotic devices have been proposed to meet the rising need for high intensity, long duration, and goal-oriented therapy required to regain motor function after neurological injury. Complementing this application, exoskeletons can augment traditional clinical assessments through precise, repeatable measurements of joint angles and movement quality. ...