Inspired by the historical construction technique and contemporary form-finding methods, as well as practices in designing and constructing masonry vaults, the thesis explores different forms that can be built without...
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Inspired by the historical construction technique and contemporary form-finding methods, as well as practices in designing and constructing masonry vaults, the thesis explores different forms that can be built without centering during construction. This thesis examines the literature associated with the geometries, construction techniques and methods used to generate masonry arches, vaults, and domes without centering or with minimum supports. The main idea about which lies on the self-supporting courses where each masonry unit has its own equilibrium condition. Based on the principles of equilibrium, this research develops algorithms for two cases: when bricks are not bonded with mortar and are bonded with mortar. The algorithms to generate an arch when subjected to additional vertical load for both cases have also been ***, using the python component in Grasshopper, a tool is developed using the proposed algorithms in this thesis. The tool is used for parametric designs to create new forms of masonry vaults which could be built without centering.
The current paper reports the results of a series of high cycle fatigue (HCF) experiments on steel welded T-joints, tested under constant amplitude three-point bending. The eXtended Finite Element Method (XFEM) was th...
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The current paper reports the results of a series of high cycle fatigue (HCF) experiments on steel welded T-joints, tested under constant amplitude three-point bending. The eXtended Finite Element Method (XFEM) was then implemented to simulate the experiments. The crack and its growth were characterised by means of level set functions to eliminate the need for re-meshing. The study can be viewed as a first-of-its-kind in XFEM fatigue simulation of butt welded steel T-joints;where the crack geometry and growth is essentially three dimensional, making the problem particularly acute. The XFEM/fatigue crack growth (FCG) procedure employed in the study was first validated against constant amplitude HCF experiments on notched steel plates from other researchers. The same modelling procedure was then used for simulating the fatigue tests conducted on steel welded T-joints. It was found that the XFEM predictions for the crack growth, the growth rate, number of cycles to failure, crack shape and final crack size were satisfactorily comparable to those obtained in the experiments. Mean errors in the XFEM predictions for the fatigue life ranged from -20.7% to +0.9%. The morphology of the fracture surface from the numerical model, in general, had a good agreement with the corresponding experimental morphology.
Modern non-contact methods for data acquisition are becoming widely used for monitoring soil erosion and for assessing soil degradation after rainfall events. Photogrammetric methods are especially favored to obtain a...
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Modern non-contact methods for data acquisition are becoming widely used for monitoring soil erosion and for assessing soil degradation after rainfall events. Photogrammetric methods are especially favored to obtain a detailed and precise digital surface model (DSM) of the surveyed area. This paper introduces the algorithm and its python implementation as a tool for ArcGIS software, which makes efficient automatic calculations of the volume of erosion rills or gullies. The input parameters are a DSM, and the rill edge polygon. The method was tested on an artificially created rill, where the result acquired using presented method was compared to the real volume. The comparison showed that the algorithm may underestimate the volume by 10-15%. In addition, the influence of the position of the rill edge polygon was tested on two DSMs of erosion rills. The resulting volumes of the rills, calculated on the basis of eight different edge polygons, varied by 5%. The algorithm also automates interpolation of the surface prior to erosion, which simplifies its usage in firstly monitored regions. The algorithm can also be used for volumetric analyses in other research areas and it is made available as a supplement of the publication.
Glaciers and snow cover area (SCA) plays an important role in river runoff in Himalayan region. There is a need to monitor SCA on spatio-temporal basis for better and efficient utilization of water resources. Moderate...
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Glaciers and snow cover area (SCA) plays an important role in river runoff in Himalayan region. There is a need to monitor SCA on spatio-temporal basis for better and efficient utilization of water resources. Moderate Resolution Imaging Spectroradiometer (MODIS) provides less cloudy data due to high temporal resolution as compared to other optical sensors for high elevation regions, and its 8-day snow cover product is globally used for snow cover estimation. The main objective of the present paper is to estimate annual and seasonal SCA in Chandra basin, Western Himalaya, and analysis of its variation with elevation, aspect, and slope during 2001 to 2017 using MODIS Terra (MOD10A2) and Aqua (MYD10A2) snow cover product as well as to correlate the same with temperature and precipitation using fifth generation European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Reanalysis of the global climate (ERA5) data. The total average SCA observed is 84.94% of basin area during the study period. The maximum annual average SCA was found as 91.23% in 2009 with minimum being 76.37% in 2016. Strong correlation is observed in annual and seasonal SCA with temperature which indicate that SCA variability is highly sensitive to temperature.
The prediction of the mechanical strength of composites must be known before use or fabrication. The computerized modeling and analysis helps in prediction of the realistic performance of the composite products. The c...
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The prediction of the mechanical strength of composites must be known before use or fabrication. The computerized modeling and analysis helps in prediction of the realistic performance of the composite products. The current research work presents the modeling routs of yarns, yarn interpolation for path, cross-section, and orientations with finite element analysis of woven fabric reinforcements. The geometrical modeling routes of textile woven reinforcements at meso-scale described by using TexGen 3.10, which is a python scripted software package, developed by the polymer composites group at the University of Nottingham, UK, works as a preprocessor for characterization of textile reinforcements. The finite element analysis of textile woven reinforcements is done by using a commercially available software package ABAQUS 6.14-5. Due to the similarity of python scripted codes in both the software’s, ABAQUS is considered as an analysis tool for textile reinforcements among the so many FE based platforms. Textile woven fabric unit cell having plain and twill weaving patterns are explained with Kevlar (monolithic) and Carbon-Kevlar (hybrid) yarns with finite element compression behaviour analysis, and discussed to understand the mechanical performance of polymer textile composites.
Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS （Geogr...
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Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS （Geographic Information System） software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and python script.
Intercropping switchgrass (Panicum virgatum) with pine can increase bioenergy feedstock production without land opportunity costs but can potentially alter water budgets. Measuring evapotranspiration (ET) and its para...
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Intercropping switchgrass (Panicum virgatum) with pine can increase bioenergy feedstock production without land opportunity costs but can potentially alter water budgets. Measuring evapotranspiration (ET) and its parameters (stomatal conductance (g(s)), leaf area index (LAI), canopy temperature (T-c), and soil moisture (SM)) across cropping systems is costly and time-consuming. However, interpretation of remotely-sensed data can facilitate the effective assessment of relative ET demands among competing forest landuses. This study develops and tests geospatial models informed by a normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), vegetation vigor index (VVI), and other spectral information to estimate ET and its parameters, which are measured on experimental watersheds with young pines and natural understory (YP), switchgrass only (SG), and young pine intercropped with switchgrass (IC). The treatment watersheds were replicated on three sites located across the Southeastern U.S. in Carteret, NC;Calhoun, MS;and Greene, AL. Despite the growth inconsistency for the SG only treatment, remote modeling estimation of ET parameters yielded an acceptable R-2 > 0.70, and the ET model yielded R-2 of 0.50 and a standard error of prediction of 0.94. However, ET and ET parameter model estimation for the IC performed somewhat less satisfactorily, with an R-2 of 0.47, 0.59, 0.56, 0.81, and 0.57 for ET, LAI, g(s), T-c, and SM, respectively, potentially due to inconsistencies in Landsat image pixel size and landuse homogeneity. Moreover, ET parameter models for the YP site performed rather poorly, with R-2 = 0.28, 0.63, and 0.76 for LAI, g(s), and T-c, respectively. Additionally, image analysis automation was created with python scripting and geospatial models. The findings from this study suggest that inclusion of more spatial variability, sound data mining, ultra-high resolution imagery and advanced image processing approaches to account for potent
In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFia s ability to be used as the Software Defined Network emulator w...
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In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFia s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organizationas computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment a Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It pr
Abaqus (R) is a popular software suite for finite element analysis. It delivers linear and nonlinear analyses of mechanical and fluid dynamics, includes multi-body system and multi-physics coupling. However, the visua...
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Abaqus (R) is a popular software suite for finite element analysis. It delivers linear and nonlinear analyses of mechanical and fluid dynamics, includes multi-body system and multi-physics coupling. However, the visualization capability of Abaqus using its CAE module is limited. Models from microtomography have extremely complicated structures, and datasets of Abaqus output are huge, requiring a visualization tool more powerful than Abaqus/CAE. We convert Abaqus output into the XML-based VTK format by developing a python script and then using ParaView to visualize the results. Such capabilities as volume rendering, tensor glyphs, superior animation and other filters allow ParaView to offer excellent visualizing manifestations. ParaView's parallel visualization makes it possible to visualize very big data. To support full parallel visualization, the python script achieves data partitioning by reorganizing all nodes, elements and the corresponding results on those nodes and elements. The data partition scheme minimizes data redundancy and works efficiently. Given its good readability and extendibility, the script can be extended to the processing of more different problems in Abaqus. We share the script with Abaqus users on GitHub.
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