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Full-Text Articles in Engineering

Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider Sep 2020

Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)

The long term behavior of composites have been extensively studied for the last four decades. Given the heterogeneity of these materials, the damage accumulation mechanisms lead to superior fatigue performance of composites compared to metals. However, due to the ‘sudden death’ behavior controlled by defect coupling, the precursor to fracture plane development of these materials, the challenge remains on how to assess the real-time material state and predict when it becomes critical? In the recent past, broadband dielectric spectroscopy (BbDS) has been used successfully to assess the material state and predict the material state change (triggered by defect coupling) for …


Unsupervised Learning Methods For Identification Of Defects In Heterogeneous Materials, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider Sep 2020

Unsupervised Learning Methods For Identification Of Defects In Heterogeneous Materials, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)

The complexity of composite materials due to the nature of their numerous laminated layers, stacking sequences, type of fibers, resin, and other external factors has challenged the world of structural health monitoring (SHM) and non-destructive inspection (NDI). Post-processing of these SHM and NDI methods has been mostly a manual time-consuming process, with human inspection causing errors associated with the bias decision made by NDI inspectors. Recent advances also call for Cure On The Fly (COTF), by integrating NDI with advanced technologies and analysis techniques such as Artificial Intelligence (AI) and Machine Learning (ML) for on-line real-time predictions of a defect, …


A Multi-Objective Model For Sustainable Perishable Food Distribution Considering The Impact Of Temperature On Vehicle Emissions And Product Shelf Life, Amin Gharehyakheh, Caroline C. Krejci, Jaime Cantu, K. Jamie Rogers Aug 2020

A Multi-Objective Model For Sustainable Perishable Food Distribution Considering The Impact Of Temperature On Vehicle Emissions And Product Shelf Life, Amin Gharehyakheh, Caroline C. Krejci, Jaime Cantu, K. Jamie Rogers

Industrial, Manufacturing, and Systems Engineering Faculty Publications

The food distribution process is responsible for significant quality loss in perishable products. However, preserving quality is costly and consumes a tremendous amount of energy. To tackle the challenge of minimizing transportation costs and CO2 emissions while also maximizing product freshness, a novel multi-objective model is proposed. The model integrates a vehicle routing problem with temperature, shelf life, and energy consumption prediction models, thereby enhancing its accuracy. Non-dominated sorting genetic algorithm II is adapted to solve the proposed model for the set of Solomon test data. The conflicting nature of these objectives and the sensitivity of the model to shelf …


Gas Component Transport Across The Soil-Atmosphere Interface For Gases Of Different Density: Experiments And Modeling, L. M. Bahlmann, K. M. Smits, K. Heck, E. Coltman, R. Helmig, I. Neuweiler Aug 2020

Gas Component Transport Across The Soil-Atmosphere Interface For Gases Of Different Density: Experiments And Modeling, L. M. Bahlmann, K. M. Smits, K. Heck, E. Coltman, R. Helmig, I. Neuweiler

Civil Engineering Faculty Publications

We investigate the influence of near-surface wind conditions on subsurface gas transport and on soil-atmosphere gas exchange for gases of different density. Results of a sand tank experiment are supported by a numerical investigation with a fully coupled porous medium-free flow model, which accounts for wind turbulence. The experiment consists of a two-dimensional bench-scale soil tank containing homogeneous sand and an overlying wind tunnel. A point source was installed at the bottom of the tank. Gas concentrations were measured at multiple horizontal and vertical locations. Tested conditions include four wind velocities (0.2/1.0/2.0/2.7 m/s), three different gases (helium: light, nitrogen: neutral, …


An Urban Modelling Framework For Climate Resilience In Low-Resource Neighbourhoods, Ulrike Passe, Michael Dorneich, Caroline Krejci, Diba Malekpour Koupaei, Breanna Marmur, Linda Shenk, Jacklin Stonewall, Janette Thompson, Yuyu Zhou Jul 2020

An Urban Modelling Framework For Climate Resilience In Low-Resource Neighbourhoods, Ulrike Passe, Michael Dorneich, Caroline Krejci, Diba Malekpour Koupaei, Breanna Marmur, Linda Shenk, Jacklin Stonewall, Janette Thompson, Yuyu Zhou

Industrial, Manufacturing, and Systems Engineering Faculty Publications

Climate predictions indicate a strong likelihood of more frequent, intense heat events. Resource-vulnerable, low-income neighbourhood populations are likely to be strongly impacted by future climate change, especially with respect to an energy burden. In order to identify existing and new vulnerabilities to climate change, local authorities need to understand the dynamics of extreme heat events at the neighbourhood level, particularly to identify those people who are adversely affected. A new comprehensive framework is presented that integrates human and biophysical data: occupancy/behaviour, building energy use, future climate scenarios and near-building microclimate projections. The framework is used to create an urban energy …


The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Jan Vanderborght, Kathleen M. Smits Jun 2020

The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Jan Vanderborght, Kathleen M. Smits

Civil Engineering Faculty Publications

Understanding the effect of the top soil layer on surface evaporation and water distribution is critical to modeling hydrological systems. However, the dependency of near-surface soil moisture and fluxes on layering characteristics remains unclear. To address this uncertainty, we investigate how the arrangement of soil horizons affects the evaporation and soil moisture, specifically, the near-surface soil moisture, through the combination of numerical simulations and evaporation experiments. The characteristics of fluxes and moisture from different soil profiles are then used to understand the soil layering conditions. Results show that the top soil layer can significantly affect the evolution of soil moisture …


Effects Of “Soil-Like” Particle Size On Gas Transport And Water Retention Properties In Aged Municipal Solid Waste From A Sri Lankan Open Dumpsite, M. Shanujah, T.K.K. Chamindu Deepagoda, A. K. Karunarathna, M. C. M. Nasvi, V. Shreedharan, G. L. S. Babu, Kathleen M. Smits, Curtis M. Oldenburg May 2020

Effects Of “Soil-Like” Particle Size On Gas Transport And Water Retention Properties In Aged Municipal Solid Waste From A Sri Lankan Open Dumpsite, M. Shanujah, T.K.K. Chamindu Deepagoda, A. K. Karunarathna, M. C. M. Nasvi, V. Shreedharan, G. L. S. Babu, Kathleen M. Smits, Curtis M. Oldenburg

Civil Engineering Faculty Publications

Open dumps constitute a major source of greenhouse gases (GHGs), predominantly methane and carbon dioxide, in developing countries. In an aged dump, typical waste composition is dominated by the “soil-like” fraction of which physical, hydraulic and gas transport characteristics markedly affect GHG emissions. This study characterized soil-gas diffusivity (Dp/D0), soil-water characteristics (SWC), and particle size distribution in “soil-like” fractions of aged solid waste retrieved at 2.5–5 m depth from an old open dumpsite situated at Kurunegala, Sri Lanka. The “soil-like” fraction was proportioned into three groups based on particle size (0–4.75, 4.75–9.5, and 9.5–25 mm) to investigate the particle size …


Evaporation From Undulating Soil Surfaces Under Turbulent Airflow Through Numerical And Experimental Approaches, Bo Gao, John Farnsworth, Kathleen M. Smits May 2020

Evaporation From Undulating Soil Surfaces Under Turbulent Airflow Through Numerical And Experimental Approaches, Bo Gao, John Farnsworth, Kathleen M. Smits

Civil Engineering Faculty Publications

Evaporation from undulating soil surfaces is rarely studied due to limited modeling theory and inadequate experimental data linking dynamic soil and atmospheric interactions. The goal of this paper is to provide exploratory insights into evaporation behavior from undulating soil surfaces under turbulent conditions through numerical and experimental approaches. A previously developed and verified coupled free flow and porous media flow model was extended by incorporating turbulent airflow through Reynolds-averaged Navier–Stokes equations. The model explicitly describes the relevant physical processes and the key properties in the free flow, porous media, and at the interface, allowing for the analysis of coupled exchange …


Gas-Diffusivity Based Characterization Of Aggregated Agricultural Soils, J.R.R.N. Jayarathne, T.K.K. Chamindu Deepagoda, Timothy J. Clough, M.C.M. Nasvi, Steve Thomas, Bo Elberling, Kathleen Smits Feb 2020

Gas-Diffusivity Based Characterization Of Aggregated Agricultural Soils, J.R.R.N. Jayarathne, T.K.K. Chamindu Deepagoda, Timothy J. Clough, M.C.M. Nasvi, Steve Thomas, Bo Elberling, Kathleen Smits

Civil Engineering Faculty Publications

Grazed pastures and cultivated fields are significant sources of greenhouse gas (GHG) emissions, in particular N2O emissions derived from fertilizer deposition and animal excreta. Net surface emissions rely on subsurface gas transfer controlled mainly by diffusion, expressed as the soil-gas diffusivity (Dp/Do). The value of Dp/Do is a function of soil air-filled porosity (e) and gaseous phase tortuosity (T), both of which vary with soil physical properties including soil texture and structure. Agricultural soils are often structurally aggregated and characterized by two distinct regions (inter- and intra-aggregated pores), however, such soils are subjected to frequent compaction and tillage resulting in …


Performance Enhancement And Prediction Of Composite Materials With Embedded Electrospun Piezoelectric Sensors, Rahman Jani Mazed, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Md Riaz Uddin Ahmed, Rassel Raihan, Kenneth Reifsnider Jan 2020

Performance Enhancement And Prediction Of Composite Materials With Embedded Electrospun Piezoelectric Sensors, Rahman Jani Mazed, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Md Riaz Uddin Ahmed, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)

In today’s world, continuous fiber reinforced composite materials are extensively used in the aerospace, automotive and other structural industries. Since the applications of such fibers demand for a high safety rating, it is of utmost importance for engineers who design such materials to analyze its safety. When cracks are developed in such materials, the mechanical, electrical, and thermal properties also get altered as a function of the cracks. Previous studies have shown that changes in electrical properties can be directly correlated with the development of cracks in the material which can then be used to predict the remaining life of …