{"title":"Investigation of impact dynamics of ionically crosslinking hydrogel droplets in mist-based 3D bioprinting systems","authors":"E. Madadian, S. Badr, A. Ahmadi","doi":"10.32393/csme.2021.250","DOIUrl":"https://doi.org/10.32393/csme.2021.250","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128019595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Composite materials are widely used in several engineering fields such as automotive, aerospace and ship industries. The mechanical behavior of composites is superior to that of conventional metals regarding strength/stiffness-to-weight ratios. However, composite materials and especially fiber-reinforced polymers (FRP) usually suffer from complex failure modes. Two of which are dominated by the resin material. In the present work, computed tomography (CT) was utilized to characterize the microstructural voids content in a plain epoxy resin similar to the one used in aerospace applications. A Python script was developed and implemented within the mainstream finite element (FE) software Abaqus to generate actual microstructural FE model employing computed tomography (CT) scan of highly cross-linked epoxy. The developed script enabled modeling sophisticated microstructural features such as micro-voids based on their actual physical aspects, i.e., size/location. Specimen sized models incorporating microstructural region(s) were used to investigate the material behavior and damage initiation at microscale lengths. The framework of extended finite element method (XFEM) was utilized to investigate the effect of microstructural voids on the damage process. The proposed algorithm is capable of generating a micromechanical model in less than one-minute runtime using moderate desktop computer. Prediction results proved excellent agreement compared to experimental data from the current investigation. Microstructural voids were observed to act as stress raisers and to trigger the damage process at micro-lengths and possibly leading to the final fracture.
{"title":"Actual Microstructural Voids Generation In Finite Element Analysis Utilizing Computed Tomography Scan Of Highly Cross-Linked Epoxy","authors":"A. Elruby, Stephen M. Handrigan, S. Nakhla","doi":"10.32393/csme.2021.156","DOIUrl":"https://doi.org/10.32393/csme.2021.156","url":null,"abstract":"Composite materials are widely used in several engineering fields such as automotive, aerospace and ship industries. The mechanical behavior of composites is superior to that of conventional metals regarding strength/stiffness-to-weight ratios. However, composite materials and especially fiber-reinforced polymers (FRP) usually suffer from complex failure modes. Two of which are dominated by the resin material. In the present work, computed tomography (CT) was utilized to characterize the microstructural voids content in a plain epoxy resin similar to the one used in aerospace applications. A Python script was developed and implemented within the mainstream finite element (FE) software Abaqus to generate actual microstructural FE model employing computed tomography (CT) scan of highly cross-linked epoxy. The developed script enabled modeling sophisticated microstructural features such as micro-voids based on their actual physical aspects, i.e., size/location. Specimen sized models incorporating microstructural region(s) were used to investigate the material behavior and damage initiation at microscale lengths. The framework of extended finite element method (XFEM) was utilized to investigate the effect of microstructural voids on the damage process. The proposed algorithm is capable of generating a micromechanical model in less than one-minute runtime using moderate desktop computer. Prediction results proved excellent agreement compared to experimental data from the current investigation. Microstructural voids were observed to act as stress raisers and to trigger the damage process at micro-lengths and possibly leading to the final fracture.","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132528326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
—4D printing managed to overcome some of the limitations of its predecessor, the 3D printing process, by replacing rigid structures with structures capable of changing their shape over time. The responsive nature of the 4D printed structures is of interest to several areas, including tissue engineering, which aims to restore, maintain, and improve damaged tissues or whole organs. Among the range of materials commercially available, poly (N-isopropyl acrylamide) (NIPAM) stands out as a thermo-responsive polymer compatible with different cell cultures. As much as there is already some consolidated knowledge about the material, there is still a lot to be explored in terms of 4D bioprinting technologies capable of efficiently generating NIPAM thermo-responsive structures. This work explores the impact of light incidence on a NIPAM based hydrogel to be processed by digital light processing (DLP). With the aid of a power meter, tests were performed regarding the variation of luminosity incident on the hydrogel. It was concluded that a waiting time of 20 minutes is necessary until the light source reaches a steady state of light intensity supply, and the ideal energy intensity for polymerization of a NIPAM based hydrogel using Irgacure 2959 as a photoinitiator is approximately 22mW.
{"title":"A Preliminary Study Of The Light Intensity Influence On 4D Printed Temperature-Responsive Nipam Based Hydrogels","authors":"D. Solis, A. Czekanski","doi":"10.32393/csme.2021.226","DOIUrl":"https://doi.org/10.32393/csme.2021.226","url":null,"abstract":"—4D printing managed to overcome some of the limitations of its predecessor, the 3D printing process, by replacing rigid structures with structures capable of changing their shape over time. The responsive nature of the 4D printed structures is of interest to several areas, including tissue engineering, which aims to restore, maintain, and improve damaged tissues or whole organs. Among the range of materials commercially available, poly (N-isopropyl acrylamide) (NIPAM) stands out as a thermo-responsive polymer compatible with different cell cultures. As much as there is already some consolidated knowledge about the material, there is still a lot to be explored in terms of 4D bioprinting technologies capable of efficiently generating NIPAM thermo-responsive structures. This work explores the impact of light incidence on a NIPAM based hydrogel to be processed by digital light processing (DLP). With the aid of a power meter, tests were performed regarding the variation of luminosity incident on the hydrogel. It was concluded that a waiting time of 20 minutes is necessary until the light source reaches a steady state of light intensity supply, and the ideal energy intensity for polymerization of a NIPAM based hydrogel using Irgacure 2959 as a photoinitiator is approximately 22mW.","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"314 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133352119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brendon Entz, Daniel Franko, Seamus Woodward-George, Atharva Parag Kulkarni, Alexandra Hynes, S. Bast, Addi Amaya, Sean Maw, Christoper A Amaya
{"title":"Radsat-SK Cube-Satellite Frame Design","authors":"Brendon Entz, Daniel Franko, Seamus Woodward-George, Atharva Parag Kulkarni, Alexandra Hynes, S. Bast, Addi Amaya, Sean Maw, Christoper A Amaya","doi":"10.32393/csme.2021.239","DOIUrl":"https://doi.org/10.32393/csme.2021.239","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134369302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Developing More Accurate Models Of Tornados","authors":"Niall Bannigan, Leigh Orf, E. Savory","doi":"10.32393/csme.2021.133","DOIUrl":"https://doi.org/10.32393/csme.2021.133","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"834 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133840261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Small Displacement Torsor Model To Evaluate Machining Accuracy In The Presence Of Locating And Machine Geometric Errors","authors":"Mondher Souilah, Antoine Tahan, N. Abacha","doi":"10.32393/csme.2021.47","DOIUrl":"https://doi.org/10.32393/csme.2021.47","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132064690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence Of Forcefield Selection On The Formation Of Viable Nanocrystalline Copper Structures Using The Melt Cool Method","authors":"Stephen M. Handrigan, S. Nakhla","doi":"10.32393/csme.2021.123","DOIUrl":"https://doi.org/10.32393/csme.2021.123","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131568550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molly D French, Malav Naik, Andre Ulliac, S. Selland, Carlos Lange
A transient thermal circuit model was developed by the AlbertaSat Student Team for the Northern SPIRIT cube satellites: Ex-Alta 2 (3U), YukonSat (2U) and AuroraSat (2U), which are to be launched into Low Earth Orbit. The model was used to study heat transfer and determine temperature profiles over time in each CubeSat. The thermal resistance analogy for conductive heat transfer was utilized, assuming convection as negligible under vacuum conditions. The thermal circuit model was used because of its greater modularity and computational efficiency, when compared to finite element analysis simulations, particularly for preliminary analysis when internal stack configuration is subject to change. The approach has also shown adaptability and modularity between different sizes of CubeSat structures. Thermal circuits were created for each face of the satellite, which allows for varying inputs to each side based on thermal loading. The simulations will aid in determining whether modifications to the CubeSats need to be made to ensure all on-board components remain within their predefined thermal operating ranges during orbit. The transient thermal models for the Northern SPIRIT constellation are simulated with LTSpice XVII, a circuit simulator written by Linear Technologies Inc. The thermal circuit simulations use electrical properties to represent thermal properties; where current sources represent heat sources, electrical resistances represent thermal resistances, capacitors represent heat capacity, and voltage differences represent temperature differences. LTSpice allows for accurate representation for all components within the satellites, as long as an association with thermal resistance or capacitance can be made. The thermal equivalent of each printed circuit board (PCB), the solar panels, the deployable components, and satellite bus for all three CubeSats has been created in LTSpice. The heat transfer on the outer surfaces and heat generation sources on PCBs have also been implemented to account for the transient nature of thermal loading during orbit. The individual CubeSat models will be validated through tests in the thermal vacuum
{"title":"Transient Thermal Circuit Model Of The Northern Spirit Cube Satellites","authors":"Molly D French, Malav Naik, Andre Ulliac, S. Selland, Carlos Lange","doi":"10.32393/csme.2021.180","DOIUrl":"https://doi.org/10.32393/csme.2021.180","url":null,"abstract":"A transient thermal circuit model was developed by the AlbertaSat Student Team for the Northern SPIRIT cube satellites: Ex-Alta 2 (3U), YukonSat (2U) and AuroraSat (2U), which are to be launched into Low Earth Orbit. The model was used to study heat transfer and determine temperature profiles over time in each CubeSat. The thermal resistance analogy for conductive heat transfer was utilized, assuming convection as negligible under vacuum conditions. The thermal circuit model was used because of its greater modularity and computational efficiency, when compared to finite element analysis simulations, particularly for preliminary analysis when internal stack configuration is subject to change. The approach has also shown adaptability and modularity between different sizes of CubeSat structures. Thermal circuits were created for each face of the satellite, which allows for varying inputs to each side based on thermal loading. The simulations will aid in determining whether modifications to the CubeSats need to be made to ensure all on-board components remain within their predefined thermal operating ranges during orbit. The transient thermal models for the Northern SPIRIT constellation are simulated with LTSpice XVII, a circuit simulator written by Linear Technologies Inc. The thermal circuit simulations use electrical properties to represent thermal properties; where current sources represent heat sources, electrical resistances represent thermal resistances, capacitors represent heat capacity, and voltage differences represent temperature differences. LTSpice allows for accurate representation for all components within the satellites, as long as an association with thermal resistance or capacitance can be made. The thermal equivalent of each printed circuit board (PCB), the solar panels, the deployable components, and satellite bus for all three CubeSats has been created in LTSpice. The heat transfer on the outer surfaces and heat generation sources on PCBs have also been implemented to account for the transient nature of thermal loading during orbit. The individual CubeSat models will be validated through tests in the thermal vacuum","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133878904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental Simulation Of Downburst Lines: A Particle Image Velocimetry Study Of Downburst Collisions","authors":"Kyle Graat, Shivani Jariwala, E. Savory","doi":"10.32393/csme.2021.175","DOIUrl":"https://doi.org/10.32393/csme.2021.175","url":null,"abstract":"","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122211457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, nanofibers are increasingly used in many fields such as textiles, catalysis, sensors, filtration, and tissue engineering. Therefore, a reliable, validated and automated analysis method for characterizing nanofiber morphology from scanning electron microscope (SEM) micrographs is strongly needed for all these applications. The common methods that determine the nanofiber diameter manually, are time-consuming and can be easily biased during the operation. Several commercial software development labs have developed SEM image analysis tools to automatically assess nanofiber’s orientation and diameter from a single-image analysis. However, the magnification and picture resolution can largely influence the results of nanofiber diameter. Therefore, there is a great need for a more accurate image analysis tool that can process multiple images automatically, making the result less affected by image resolution. This study aimed to develop an image processing code to determine nanofiber morphology from multiple images using MATLAB. This tool can process two images with a different magnification of one sample at the same time. On one hand, the lowmagnification image contains a larger area of the sample, providing more sampling points and a more realistic result. On the other hand, the high-magnification image can offer a more accurate diameter for low fiber size diameters. After utilizing the data from both images, this tool will automatically draw a distribution diagram contains three data sets, the low magnification data set, the high magnification data set and the combined data set, giving more statistically reliable results. In this study, median filtering, image intensity adjustment, and histogram equalization are used to reduce noise and increase the contrast of images. A local thresholding method is utilized to transform the image into a binary image using Sauvola binarization. The fiber boundaries are detected using canny edge detection. Then the fiber diameters are calculated by Euclidean distance transform matrix. These procedures ensure the analysis quality of each image and the multiple-image function makes this nanofiber diameter measurement tool more accurate and realizable than other single-image analysis ones.
{"title":"A Multiple-Image Nanofiber Diameter Measurement Tool","authors":"Erqian Gao, M. Razavi, Z. Tan","doi":"10.32393/csme.2021.29","DOIUrl":"https://doi.org/10.32393/csme.2021.29","url":null,"abstract":"In recent years, nanofibers are increasingly used in many fields such as textiles, catalysis, sensors, filtration, and tissue engineering. Therefore, a reliable, validated and automated analysis method for characterizing nanofiber morphology from scanning electron microscope (SEM) micrographs is strongly needed for all these applications. The common methods that determine the nanofiber diameter manually, are time-consuming and can be easily biased during the operation. Several commercial software development labs have developed SEM image analysis tools to automatically assess nanofiber’s orientation and diameter from a single-image analysis. However, the magnification and picture resolution can largely influence the results of nanofiber diameter. Therefore, there is a great need for a more accurate image analysis tool that can process multiple images automatically, making the result less affected by image resolution. This study aimed to develop an image processing code to determine nanofiber morphology from multiple images using MATLAB. This tool can process two images with a different magnification of one sample at the same time. On one hand, the lowmagnification image contains a larger area of the sample, providing more sampling points and a more realistic result. On the other hand, the high-magnification image can offer a more accurate diameter for low fiber size diameters. After utilizing the data from both images, this tool will automatically draw a distribution diagram contains three data sets, the low magnification data set, the high magnification data set and the combined data set, giving more statistically reliable results. In this study, median filtering, image intensity adjustment, and histogram equalization are used to reduce noise and increase the contrast of images. A local thresholding method is utilized to transform the image into a binary image using Sauvola binarization. The fiber boundaries are detected using canny edge detection. Then the fiber diameters are calculated by Euclidean distance transform matrix. These procedures ensure the analysis quality of each image and the multiple-image function makes this nanofiber diameter measurement tool more accurate and realizable than other single-image analysis ones.","PeriodicalId":446767,"journal":{"name":"Progress in Canadian Mechanical Engineering. Volume 4","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116617620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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