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Full-Text Articles in Mechanical Engineering

A Bismuth Attack At Grain-Boundaries Of Ceria-Based Electrolytes, Tianrang Yang, Kevin Huang Oct 2018

A Bismuth Attack At Grain-Boundaries Of Ceria-Based Electrolytes, Tianrang Yang, Kevin Huang

Faculty Publications

Bismuth is a common additive of commercial silver pastes for enhancing metallization effect; silver paste is also commonly used in high-temperature electrochemical cells as a current collector or contact layer. We here report that the minor amount of bismuth in commercial silver pastes can transport to the interface of electrode/Gd-doped CeO2 (GDC) electrolyte and seriously corrode grain-boundaries (GBs) of the GDC electrolyte, a commonly used intermediate-temperature electrolyte, causing significant ionic conductivity degradation. A comprehensive electron microscopic analysis reveals that the Bi-corrosion takes place along GBs of GDC electrolyte acting as “washing flux” agent, causing grain separation and thus blocking …


Nonlocal Damage Mechanics For Quantification Of Health For Piezoelectric Sensor, Amit Shelke, Anowarul Habib, Umar Amjad, Ullrich Pietsch, Sourav Banerjee Sep 2018

Nonlocal Damage Mechanics For Quantification Of Health For Piezoelectric Sensor, Amit Shelke, Anowarul Habib, Umar Amjad, Ullrich Pietsch, Sourav Banerjee

Faculty Publications

In this paper, a novel method to quantify the incubation of damage on piezoelectric crystal is presented. An intrinsic length scale parameter obtained from nonlocal field theory is used as a novel measure for quantification of damage precursor. Features such as amplitude decay, attenuation, frequency shifts and higher harmonics of guided waves are commonly-used damage features. Quantification of the precursors to damage by considering the mentioned features in a single framework is a difficult proposition. Therefore, a nonlocal field theory is formulated and a nonlocal damage index is proposed. The underlying idea of the paper is that inception of the …


Experimental Investigation Of Impact Localization In Composite Plate Using Newly Developed Imaging Method, Mohammad Faisal Haider, Asaad Migot, Md Yeasin Bhuiyan, Victor Giurgiutiu Aug 2018

Experimental Investigation Of Impact Localization In Composite Plate Using Newly Developed Imaging Method, Mohammad Faisal Haider, Asaad Migot, Md Yeasin Bhuiyan, Victor Giurgiutiu

Faculty Publications

This paper focuses on impact localization of composite structures, which possess more complexity in the guided wave propagation due to the anisotropic behavior of composite materials. In this work, a composite plate was manufactured by using a compression molding process with proper pressure and temperature cycle. Eight layers of woven composite prepreg were used to manufacture the composite plate. A structural health monitoring (SHM) technique was implemented with piezoelectric wafer active sensors (PWAS) to detect and localize the impact on the plate. There were two types of impact event that were considered in this paper (a) low energy impact event …


The Performance Of Syngas-Fueled Sofcs Predicted By A Reduced Order Model (Rom): Temperature And Fuel Composition Effects, Xinfang Jin, Anthony Ku, Atul Verma, Brandon Ohara, Kevin Huang, Surinder Singh Jul 2018

The Performance Of Syngas-Fueled Sofcs Predicted By A Reduced Order Model (Rom): Temperature And Fuel Composition Effects, Xinfang Jin, Anthony Ku, Atul Verma, Brandon Ohara, Kevin Huang, Surinder Singh

Faculty Publications

An electrochemical reduced order model (ROM) has been developed in this study to simulate the performance of syngas-fueled anode-supported SOFCs with coupled bulk chemical reactions and multi-species gas diffusion in the electrodes. Experimental V-I curves with syngas fuel were used to validate the model to ensure its high fidelity. The model was used to investigate the effects of fuel composition and temperature on the electrochemical performance of the cell, chemical reaction rate and concentration distributions of gaseous species across the anode. The results show that H2 electro-oxidation dominates the overall cell performance, and that CO contributes to the performance …


Pedestrian Injury Severity Analysis In Motor Vehicle Crashes In Ohio, Majbah Uddin, Fahim Ahmed May 2018

Pedestrian Injury Severity Analysis In Motor Vehicle Crashes In Ohio, Majbah Uddin, Fahim Ahmed

Faculty Publications

According to the National Highway Traffic Safety Administration, 116 pedestrians were killed in motor vehicle crashes in Ohio in 2015. However, no study to date has analyzed crashes in Ohio in order to explore the factors contributing to the pedestrian injury severity resulting from motor vehicle crashes. This study fills this gap by investigating the crashes involving pedestrians exclusively in Ohio. This study uses the crash data from the Highway Safety Information System, from 2009 to 2013. The explanatory factors include the pedestrian, driver, vehicle, crash, and roadway characteristics. Both fixed- and random-parameters ordered probit models of injury severity (where …


Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine Schubert Kabban, Richard Uber, Kevin Lin, Bin Li, Md Yeasin Bhuiyan, Victor Giurgiutiu Apr 2018

Uncertainty Evaluation In The Design Of Structural Health Monitoring Systems For Damage Detection, Christine Schubert Kabban, Richard Uber, Kevin Lin, Bin Li, Md Yeasin Bhuiyan, Victor Giurgiutiu

Faculty Publications

The validation of structural health monitoring (SHM) systems for aircraft is complicated by the extent and number of factors that the SHM system must demonstrate for robust performance. Therefore, a time- and cost-efficient method for examining all of the sensitive factors must be conducted. In this paper, we demonstrate the utility of using the simulation modeling environment to determine the SHM sensitive factors that must be considered for subsequent experiments, in order to enable the SHM validation. We demonstrate this concept by examining the effect of SHM system configuration and flaw characteristics on the response of a signal from a …


Highly Efficient Electrochemical Reforming Of Ch4/Co2 In A Solid Oxide Electrolyser, Jinhai Lu, Changli Zhu, Changchang Pan, Wenlie Lin, John P. Lemmon, Fanglin Chen, Chunsen Li, Kui Xie Mar 2018

Highly Efficient Electrochemical Reforming Of Ch4/Co2 In A Solid Oxide Electrolyser, Jinhai Lu, Changli Zhu, Changchang Pan, Wenlie Lin, John P. Lemmon, Fanglin Chen, Chunsen Li, Kui Xie

Faculty Publications

Reforming CH4 into syngas using CO2 remains a fundamental challenge due to carbon deposition and nanocatalyst instability. We, for the first time, demonstrate highly efficient electrochemical reforming of CH4/CO2 to produce syngas in a solid oxide electrolyser with CO2 electrolysis in the cathode and CH4 oxidation in the anode. In situ exsolution of an anchored metal/oxide interface on perovskite electrode delivers remarkably enhanced coking resistance and catalyst stability. In situ Fourier transform infrared characterizations combined with first principle calculations disclose the interface activation of CO2 at a transition state between a CO …


Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte Mar 2018

Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte

Faculty Publications

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker …


An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini Mar 2018

An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Faculty Publications

The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the …


Peri-Elastodynamic Simulations Of Guided Ultrasonic Lamb Waves In Smart Structure With Surface Mounted Pzt, Subir Patra, Hossain Ahmed, Sourav Banerjee Jan 2018

Peri-Elastodynamic Simulations Of Guided Ultrasonic Lamb Waves In Smart Structure With Surface Mounted Pzt, Subir Patra, Hossain Ahmed, Sourav Banerjee

Faculty Publications

Peridynamic based elastodynamic computation tool named Peri-elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-elastodynamics method is not only …