Thomas H. Hannah, Reuben H. Kraft, V. Martin, Stephen Ellis
Typical Kolsky bars are 10–20mm in diameter with the lengths of each main bar being on the scale of meters. To push 104 and higher strain rates smaller diameter bars, accompanied by shorter lengths, are needed. As the diameters of the bars decreases the precision in the alignment of the system must increase to maintain the same relative tolerance as the larger experimental systems. Conversely, as the size of the bars decreases so does the magnitude of gravity based frictional forces due to the decreased mass of the system. Finite Element (FE) models are typically generated assuming a perfect experiment with exact alignment and no gravity. Additionally, these simulations tend to take advantage of the radial symmetry of an ideal experiment which removes any potential for modeling non-symmetric effects but has the added benefit of a reduced computational load. In this work, we discuss some of the results of these fast-running symmetry models to establish a baseline and demonstrate the first-order use case of such methods. We then take advantage of high-performance computing techniques to generate several three-dimensional, half symmetry simulations using Abaqus® allowing modeling of gravity and misalignment. The imperfection is initially modeled using the static general process followed by a dynamic explicit simulation in which the impact portion of the test is conducted. This multi-step simulation structure creates a system that can properly investigate the impact of these real-world, non-axis symmetric effects. These simulations fully explore the impacts of these experimental realities and are described in detail to allow other researchers to implement a similar FE modeling structure to aid in their experimentation and diagnostic efforts. Both a 12.7 mm and 3.16 mm diameter bar system are evaluated to quantify the degree that these various experimental imperfections have across two size scales of Kolsky bar systems.
{"title":"Impact of Imperfect Kolsky Bar Experiments Across Different Scales Using Finite Elements","authors":"Thomas H. Hannah, Reuben H. Kraft, V. Martin, Stephen Ellis","doi":"10.1115/imece2022-96816","DOIUrl":"https://doi.org/10.1115/imece2022-96816","url":null,"abstract":"\u0000 Typical Kolsky bars are 10–20mm in diameter with the lengths of each main bar being on the scale of meters. To push 104 and higher strain rates smaller diameter bars, accompanied by shorter lengths, are needed. As the diameters of the bars decreases the precision in the alignment of the system must increase to maintain the same relative tolerance as the larger experimental systems. Conversely, as the size of the bars decreases so does the magnitude of gravity based frictional forces due to the decreased mass of the system. Finite Element (FE) models are typically generated assuming a perfect experiment with exact alignment and no gravity. Additionally, these simulations tend to take advantage of the radial symmetry of an ideal experiment which removes any potential for modeling non-symmetric effects but has the added benefit of a reduced computational load. In this work, we discuss some of the results of these fast-running symmetry models to establish a baseline and demonstrate the first-order use case of such methods. We then take advantage of high-performance computing techniques to generate several three-dimensional, half symmetry simulations using Abaqus® allowing modeling of gravity and misalignment. The imperfection is initially modeled using the static general process followed by a dynamic explicit simulation in which the impact portion of the test is conducted. This multi-step simulation structure creates a system that can properly investigate the impact of these real-world, non-axis symmetric effects. These simulations fully explore the impacts of these experimental realities and are described in detail to allow other researchers to implement a similar FE modeling structure to aid in their experimentation and diagnostic efforts. Both a 12.7 mm and 3.16 mm diameter bar system are evaluated to quantify the degree that these various experimental imperfections have across two size scales of Kolsky bar systems.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133604417","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}
The aviation industry demands innovation in new materials and processes which can demonstrate high performance with minimum weight. Strength-to-weight ratio (STR) is the key metric that drives the value justification in this demand stream. However, aviation’s test and certification procedures are time-consuming, expensive, and heavily regulated. This study proposes a Digital Twin (DT) framework to address the time and high costs of mechanical testing procedures in the aviation industry. The proposed DT utilizes new Machine Learning (ML) techniques such as Transfer Learning (TL). Hence, a proof-of-concept study using TL in the Aluminum material group has been demonstrated. The promising results revealed that it was possible to reduce the test load of new material to 40% without any significant error.
{"title":"A Digital Twin Framework for Mechanical Testing Powered by Machine Learning","authors":"M. Kahya, Cem Söyleyici, Mete Bakir, H. Ö. Ünver","doi":"10.1115/imece2022-94680","DOIUrl":"https://doi.org/10.1115/imece2022-94680","url":null,"abstract":"\u0000 The aviation industry demands innovation in new materials and processes which can demonstrate high performance with minimum weight. Strength-to-weight ratio (STR) is the key metric that drives the value justification in this demand stream. However, aviation’s test and certification procedures are time-consuming, expensive, and heavily regulated. This study proposes a Digital Twin (DT) framework to address the time and high costs of mechanical testing procedures in the aviation industry. The proposed DT utilizes new Machine Learning (ML) techniques such as Transfer Learning (TL). Hence, a proof-of-concept study using TL in the Aluminum material group has been demonstrated. The promising results revealed that it was possible to reduce the test load of new material to 40% without any significant error.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131899489","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}
Several bomb explosion assaults against military personnel, police officers, and public and civil structures have occurred in recent years, resulting in a significant loss. As a result, society requires increased protection and defense for current constructions from loads of oblasts. In the middle of the many options, retrofitting reinforced concrete and masonry structures with numerous forms and types of materials of composite and fiber is an excellent way to improve resistance to the blast. This paper provides a recent review of extant works & papers on polymers, composite & fibrous materials used for elements of structure defense from the blast, as well as a list of research gaps that need to be filled. Various innovative materials such as polymers, nanomaterials, composite materials, as well as fibrous materials are taken into consideration while writing this review paper. Composite materials have been employed in the blast and ballistic impact applications and are regarded as effective materials for absorbing blast energy. The stitching boosted the composite’s Mode I interlaminar fracture toughness, resulting in increased damage resistance. The basic composite system tested is carbon-fiber-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core. In a comparable sandwich structure, glass-fiber-reinforced polymer (GFRP) composite skins were also incorporated for comparison.
{"title":"Blast-Resistant Ballistic Materials","authors":"Nishant Thakkar","doi":"10.1115/imece2022-97137","DOIUrl":"https://doi.org/10.1115/imece2022-97137","url":null,"abstract":"\u0000 Several bomb explosion assaults against military personnel, police officers, and public and civil structures have occurred in recent years, resulting in a significant loss. As a result, society requires increased protection and defense for current constructions from loads of oblasts. In the middle of the many options, retrofitting reinforced concrete and masonry structures with numerous forms and types of materials of composite and fiber is an excellent way to improve resistance to the blast. This paper provides a recent review of extant works & papers on polymers, composite & fibrous materials used for elements of structure defense from the blast, as well as a list of research gaps that need to be filled. Various innovative materials such as polymers, nanomaterials, composite materials, as well as fibrous materials are taken into consideration while writing this review paper. Composite materials have been employed in the blast and ballistic impact applications and are regarded as effective materials for absorbing blast energy. The stitching boosted the composite’s Mode I interlaminar fracture toughness, resulting in increased damage resistance. The basic composite system tested is carbon-fiber-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core. In a comparable sandwich structure, glass-fiber-reinforced polymer (GFRP) composite skins were also incorporated for comparison.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129072248","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}
Zihao Yuan, Ruinan Mu, Jiafeng Yang, Ke Wang, Haifeng Zhao
In this work, a dynamic model is proposed to simulate the drilling and steering processing of an autonomous burrowing mole to access scientific samples from the deep subsurface of the Moon. The locomotive module is idealized as a rigid beam. The characteristic parameters are considered including the length, cross-section diameter and centroid of a cylindrical rod. Based on the Lagrangian mechanics, a 3-DOF dynamic model for the locomotion of autonomous device underground is developed. By introducing the contact algorithm and resistive force theory, the interaction scheme between the locomotive body and regolith is described. The effect of characteristic parameters on resistive force and torque is studied and discussed through numerical experiments. The simulation results show that this method may adapt to a variety of drilling and burrowing motions in the lunar subsurface environments. Overall, the proposed method actually provides a reduced-order model to simulate the operating and controlling scenarios an autonomous burrowing robot in lunar subsurface. It may be further generalized to consider more complex conditions, including depth-dependent regolith model, 3D trajectory planning and navigation algorithms, etc. This model may provide intuitive inputs to plan the space missions of a drilling robot to obtain surface samples in an extraterrestrial planet, such as the Moon or Mars, etc.
{"title":"A Dynamics Model of Locomotive Mechanism Drilling Into Lunar Regolith","authors":"Zihao Yuan, Ruinan Mu, Jiafeng Yang, Ke Wang, Haifeng Zhao","doi":"10.1115/imece2022-95251","DOIUrl":"https://doi.org/10.1115/imece2022-95251","url":null,"abstract":"\u0000 In this work, a dynamic model is proposed to simulate the drilling and steering processing of an autonomous burrowing mole to access scientific samples from the deep subsurface of the Moon. The locomotive module is idealized as a rigid beam. The characteristic parameters are considered including the length, cross-section diameter and centroid of a cylindrical rod. Based on the Lagrangian mechanics, a 3-DOF dynamic model for the locomotion of autonomous device underground is developed. By introducing the contact algorithm and resistive force theory, the interaction scheme between the locomotive body and regolith is described. The effect of characteristic parameters on resistive force and torque is studied and discussed through numerical experiments. The simulation results show that this method may adapt to a variety of drilling and burrowing motions in the lunar subsurface environments. Overall, the proposed method actually provides a reduced-order model to simulate the operating and controlling scenarios an autonomous burrowing robot in lunar subsurface. It may be further generalized to consider more complex conditions, including depth-dependent regolith model, 3D trajectory planning and navigation algorithms, etc. This model may provide intuitive inputs to plan the space missions of a drilling robot to obtain surface samples in an extraterrestrial planet, such as the Moon or Mars, etc.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123593657","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}
Polyjet printing, a multi-jet Additive Manufacturing technique, has been used to fabricate 3-Dimensional structures for various polymeric material systems. This technique uses a layer-by-layer deposition method and allows for the fabrication of parts with different material compositions and varying thermomechanical properties. The current research investigates the influence of process-induced variation on Mode 1(K1C) fracture toughness of the Vero material system. Compact Tension (C-T) specimens with crack fronts parallel and perpendicular to the print direction were fabricated. The orientation of the crack front relative to the print and build directions influenced the Mode I fracture toughness values. When the crack front was parallel to the print plane, K1C decreased by 49.54%, G1C decreased by 41.56%, and peak load intensity decreased by 52.76% compared to the perpendicular crack front orientation. C-T samples were modeled in CAD to correlate with the experimental results and then analyzed in the Ansys workbench. The FEA yielded a Mode 1 fracture toughness value of 2.48 MPa m0.5 for a perpendicular configuration of the crack front and a fracture toughness value of 1.15 MPa m0.5 for a parallel configuration of the crack front. The Representative Volume Element method is used for a composite containing the Vero material system as a matrix and carbon nanofibers as reinforcement. Carbon nanofibers are integrated using a customized material configuration, and their influence on fracture is studied. A tailored network perpendicular to the crack front in a 3D printed C-T specimen stiffens the specimen. In contrast, a tailored network parallel to the crack front has a relaxing impact, indicating that an additively created part may be prone to softening under certain conditions.
{"title":"Experimental and Numerical Investigation of the Influence of Crack Front Orientation in Mode 1 Plane Strain Fracture Toughness of a Vero Material System via Poly Jet Additive Manufacturing","authors":"Vishwanath Khapper, R. Mohan","doi":"10.1115/imece2022-96915","DOIUrl":"https://doi.org/10.1115/imece2022-96915","url":null,"abstract":"\u0000 Polyjet printing, a multi-jet Additive Manufacturing technique, has been used to fabricate 3-Dimensional structures for various polymeric material systems. This technique uses a layer-by-layer deposition method and allows for the fabrication of parts with different material compositions and varying thermomechanical properties. The current research investigates the influence of process-induced variation on Mode 1(K1C) fracture toughness of the Vero material system. Compact Tension (C-T) specimens with crack fronts parallel and perpendicular to the print direction were fabricated. The orientation of the crack front relative to the print and build directions influenced the Mode I fracture toughness values. When the crack front was parallel to the print plane, K1C decreased by 49.54%, G1C decreased by 41.56%, and peak load intensity decreased by 52.76% compared to the perpendicular crack front orientation. C-T samples were modeled in CAD to correlate with the experimental results and then analyzed in the Ansys workbench. The FEA yielded a Mode 1 fracture toughness value of 2.48 MPa m0.5 for a perpendicular configuration of the crack front and a fracture toughness value of 1.15 MPa m0.5 for a parallel configuration of the crack front. The Representative Volume Element method is used for a composite containing the Vero material system as a matrix and carbon nanofibers as reinforcement. Carbon nanofibers are integrated using a customized material configuration, and their influence on fracture is studied. A tailored network perpendicular to the crack front in a 3D printed C-T specimen stiffens the specimen. In contrast, a tailored network parallel to the crack front has a relaxing impact, indicating that an additively created part may be prone to softening under certain conditions.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"4661 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129396548","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}
Can Yang, Ruifeng Chen, Jianzhong Xie, Zuguang Ding, Yang Shu, Xiao-Hong Yin
With the increasingly serious problem of white pollution, biodegradable substitutes that can replace the existing plastic materials are in urgent need. In the present work, thermal shock experiments were carried out to investigate the heat resistance of injection molded F6510 products under specific humidity/temperature conditions. Specifically, two groups of experiments were designed at a constant humidity of 90%. For single-point temperature (SPT) experiments, the testing temperature was varied from 30°C to 75 °C with an interval of 5/10 °C, and for the thermal cycle (TC) experiments, samples underwent 60 °C -(-20 °C)-60 °C thermal cycles. The SPT experiments showed that samples began to deform at 45 °C, with 0.05mm increase in length, and 0.02mm decrease in both width and height, and the shape variation increases with enhanced temperature. Meanwhile, TC experiment samples showed obvious shrinkage during the nine-day testing period, with a maximal size variation of 0.44mm for the length. In addition, DSC results showed a higher crystallinity degree for the inner layer of samples. This is due to the slower cooling rate of the inner layer, facilitating polymer molecular chain migration and thus the crystal nucleus growing, which was supported by Moldex3D simulation analyses. Double melting peaks appeared in the heating stage of DSC test, indicating the formation of both α and α’ crystal forms, which has been verified by both thermal shock experiments and DSC tests. The findings of this work indicate that the crystallinity, crystal form, and thus the products’ heat resistance of F6510 can be improved by reasonably controlling injection molding parameters such as the mold temperature and cooling time.
{"title":"Study on Heat Resistance of PLA Based Biodegradable Injection Molded Components","authors":"Can Yang, Ruifeng Chen, Jianzhong Xie, Zuguang Ding, Yang Shu, Xiao-Hong Yin","doi":"10.1115/imece2022-88662","DOIUrl":"https://doi.org/10.1115/imece2022-88662","url":null,"abstract":"\u0000 With the increasingly serious problem of white pollution, biodegradable substitutes that can replace the existing plastic materials are in urgent need. In the present work, thermal shock experiments were carried out to investigate the heat resistance of injection molded F6510 products under specific humidity/temperature conditions. Specifically, two groups of experiments were designed at a constant humidity of 90%. For single-point temperature (SPT) experiments, the testing temperature was varied from 30°C to 75 °C with an interval of 5/10 °C, and for the thermal cycle (TC) experiments, samples underwent 60 °C -(-20 °C)-60 °C thermal cycles. The SPT experiments showed that samples began to deform at 45 °C, with 0.05mm increase in length, and 0.02mm decrease in both width and height, and the shape variation increases with enhanced temperature. Meanwhile, TC experiment samples showed obvious shrinkage during the nine-day testing period, with a maximal size variation of 0.44mm for the length. In addition, DSC results showed a higher crystallinity degree for the inner layer of samples. This is due to the slower cooling rate of the inner layer, facilitating polymer molecular chain migration and thus the crystal nucleus growing, which was supported by Moldex3D simulation analyses. Double melting peaks appeared in the heating stage of DSC test, indicating the formation of both α and α’ crystal forms, which has been verified by both thermal shock experiments and DSC tests. The findings of this work indicate that the crystallinity, crystal form, and thus the products’ heat resistance of F6510 can be improved by reasonably controlling injection molding parameters such as the mold temperature and cooling time.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122389462","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}
Rufaidah Salim, Mahmoud Rezk, Mohammed Minhas Anzil, Nawal Aljasmi, Amit Shukla
Energy transmission systems have expanded significantly, given the increase in demand for power generation. This increase in size has led to the need of a robust inspection method. Overhead Line (OHL) systems consist of many critical components such as insulators, poles, and power lines, which need to be inspected regularly. With recent advancements, drones equipped with multiple sensors are flown, either manually or autonomously, for inspection. This paper proposes autonomous vision-based navigation of the drone over OHL. The navigation is achieved through the feedback from the camera onboard the drone. A deep learning-based model is developed for the detection of the various OHL components, which are then utilized to design the path for the drone to navigate. Furthermore, a virtual safety bubble (VSB) is developed around the drone upon the detection of the components. This VSB is part of local autonomy of the drone and ensures that a constant safe distance is always maintained from the components. This approach can help reduce the overall inspection time of OHL with less cognitive load on the operator. It also ensures the safety of the OHL installations and drone. Although the paper focuses mainly on running the experiments in a simulation environment, this could be imitated in real-life situations.
{"title":"Vision Based Safe Navigation of UAV for Overhead Line Inspection Enabled by Virtual Safety Bubble","authors":"Rufaidah Salim, Mahmoud Rezk, Mohammed Minhas Anzil, Nawal Aljasmi, Amit Shukla","doi":"10.1115/imece2022-95358","DOIUrl":"https://doi.org/10.1115/imece2022-95358","url":null,"abstract":"\u0000 Energy transmission systems have expanded significantly, given the increase in demand for power generation. This increase in size has led to the need of a robust inspection method. Overhead Line (OHL) systems consist of many critical components such as insulators, poles, and power lines, which need to be inspected regularly. With recent advancements, drones equipped with multiple sensors are flown, either manually or autonomously, for inspection. This paper proposes autonomous vision-based navigation of the drone over OHL. The navigation is achieved through the feedback from the camera onboard the drone. A deep learning-based model is developed for the detection of the various OHL components, which are then utilized to design the path for the drone to navigate. Furthermore, a virtual safety bubble (VSB) is developed around the drone upon the detection of the components. This VSB is part of local autonomy of the drone and ensures that a constant safe distance is always maintained from the components. This approach can help reduce the overall inspection time of OHL with less cognitive load on the operator. It also ensures the safety of the OHL installations and drone. Although the paper focuses mainly on running the experiments in a simulation environment, this could be imitated in real-life situations.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128546594","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}
Amer D. Alotaibi, A. Abubakar, S. S. Akhtar, A. Hakeem, K. Al-Athel, A. Arif
The present study deals with the development of α-SiAlON-4%Co and α-SiAlON-20%TiCN ceramic composites with desirable properties tailored for enhanced high-cutting tool performance. The effective medium theories and mean-field homogenization schemes are used to design and optimize the volume fractions, the interfacial thermal resistance, and reinforcement particle sizes while incorporating the influence of porosity on the effective properties of the ceramic composites. The designed composites are fabricated via the spark plasma sintering process. The ceramic samples are characterized/analyzed via scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. The effective thermal and structural properties of the composites are measured and compared to that of the computational predictions. The results indicate that excellent densification in α-SiAlON-based composites can be achieved by the use of spark plasma sintering process. Experimentally measured properties of SiAlON-20%TiCN composite compare well with that of the computational predictions and have shown significant enhancement in its effective thermal conductivity and fracture toughness. The measured properties of SiAlON-4%Co composite did not meet the predictions due to Co agglomeration and the large thermal mismatch between the matrix and the inclusion, which emphasizes the need to optimize the synthesis process and establish volume fraction limits of Co in α-SiAlON ceramic composites.
{"title":"Design and Development of Novel α-SiAlON/Co and α-SiAlON/TiCN Composites for Cutting Tool Inserts","authors":"Amer D. Alotaibi, A. Abubakar, S. S. Akhtar, A. Hakeem, K. Al-Athel, A. Arif","doi":"10.1115/imece2022-94964","DOIUrl":"https://doi.org/10.1115/imece2022-94964","url":null,"abstract":"\u0000 The present study deals with the development of α-SiAlON-4%Co and α-SiAlON-20%TiCN ceramic composites with desirable properties tailored for enhanced high-cutting tool performance. The effective medium theories and mean-field homogenization schemes are used to design and optimize the volume fractions, the interfacial thermal resistance, and reinforcement particle sizes while incorporating the influence of porosity on the effective properties of the ceramic composites. The designed composites are fabricated via the spark plasma sintering process. The ceramic samples are characterized/analyzed via scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. The effective thermal and structural properties of the composites are measured and compared to that of the computational predictions. The results indicate that excellent densification in α-SiAlON-based composites can be achieved by the use of spark plasma sintering process. Experimentally measured properties of SiAlON-20%TiCN composite compare well with that of the computational predictions and have shown significant enhancement in its effective thermal conductivity and fracture toughness. The measured properties of SiAlON-4%Co composite did not meet the predictions due to Co agglomeration and the large thermal mismatch between the matrix and the inclusion, which emphasizes the need to optimize the synthesis process and establish volume fraction limits of Co in α-SiAlON ceramic composites.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128794096","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}
M. Moshtaghzadeh, N. Rangel, A. Bejan, Pezhman Mardanpour
The purpose of this paper is to examine how rib configurations and spar configurations influence flying wing stability. Flying wing aircraft exhibit enhanced flutter characteristics when stresses flow smoothly through the wing. We prevent stress strangulation through spar cross-sections by changing the configuration in the plunge direction. We employ and develop computer programs Gmsh, Variational Asymptotic Beam Sectional Analysis, MATLAB scripts, and Nonlinear Aeroelastic Trim and Stability of High Altitude Long Endurance Aircraft. The configurations are designed by considering the same material, mass, and flight conditions. The results indicate that the design with the smoother stress distribution through the wing has a higher flutter speed. It is shown that the σ11 and Von-Misses stress distributions have an important effect on the stability of a flying wing aircraft.
{"title":"An Evolutionary Aeroelastic Design Approach for Spars and Ribs of Flying Wing Aircraft","authors":"M. Moshtaghzadeh, N. Rangel, A. Bejan, Pezhman Mardanpour","doi":"10.1115/imece2022-90385","DOIUrl":"https://doi.org/10.1115/imece2022-90385","url":null,"abstract":"\u0000 The purpose of this paper is to examine how rib configurations and spar configurations influence flying wing stability. Flying wing aircraft exhibit enhanced flutter characteristics when stresses flow smoothly through the wing. We prevent stress strangulation through spar cross-sections by changing the configuration in the plunge direction. We employ and develop computer programs Gmsh, Variational Asymptotic Beam Sectional Analysis, MATLAB scripts, and Nonlinear Aeroelastic Trim and Stability of High Altitude Long Endurance Aircraft. The configurations are designed by considering the same material, mass, and flight conditions. The results indicate that the design with the smoother stress distribution through the wing has a higher flutter speed. It is shown that the σ11 and Von-Misses stress distributions have an important effect on the stability of a flying wing aircraft.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"625 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133322475","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}
S. Chandrasekaran, A. el-Ghannam, J. Monroe, Chengying Xu
Due to its excellent stiffness, thermal stability and low density, silicon carbide (SiC) is an excellent candidate for fabrication of lightweight substrates for space mirrors in telescopes and satellites. However, the strong Si-C covalent bond induces high thermal stability and mechanical strength which makes it difficult to manufacture dense SiC. Other ceramic mirror materials such as Cordierite (CO720) by Kyocera® and Spodumene (ZERODUR®) by Schott® are characterized by their light weight, near zero thermal expansion coefficient and excellent thermal properties. However, mirrors made of cordierite or spodumene have relatively low stiffness and unsatisfactory thermal conductivity. We hypothesize that composites made of SiC-Cordierite and SiC-Spodumene can serve as better mirror substrates characterized by high stiffness, high thermal conductivity and improved thermomechanical stability. The present study reports on the synthesis and characterization of SiC-Cordierite (SiC-Cord) and SiC-Spodumene (SiC-Spod) using powder metallurgy method. The densification and thermomechanical stability of the SiC-mineral composites are enhanced by a novel in situ mineralization mechanism at the interface between the SiC and mineral binders between 800 °C and 1200 °C. The densities of SiC-Cord and SiC-Spod composites were 2.74 g/cc and 2.61 g/cc, respectively, while the thermal conductivities were 6.737 W/m. K and 3.281 W/m. K, respectively. Polishing the SiC-Cord with SiC grit numbers 400–1200 and diamond/silica slurry resulted in a mirror surface with an average roughness of 2.32 nm on SiC particles. The nano indentation stiffness of the polished SiC-Cordierite composite measured 239.9 ± 20.6 GPa. The stiffness of the SiC-Cord composite is superior to that of pure cordierite (140 GPa) or Zerodur (80 GPa). The average Vickers hardness of SiC-Cordierite was 8.12 ± 4.5 GPa which was superior to that of Zerodur (6.08 GPa) and comparable to that of pure cordierite (8–8.5 GPa). The composite samples demonstrated high thermal shock resistance as indicated by their comparable compressive strength and dimensional stability before and after quenching from 1200 °C to room temperature in water. Taken altogether, the superior thermomechanical properties of SiC-Cordierite and SiC-Spodumene suggest their suitability for mirrors in space-based telescopes.
{"title":"Thermo-Mechanical Properties of SiC-Mineral Binder Composites for Space Applications","authors":"S. Chandrasekaran, A. el-Ghannam, J. Monroe, Chengying Xu","doi":"10.1115/imece2022-95056","DOIUrl":"https://doi.org/10.1115/imece2022-95056","url":null,"abstract":"\u0000 Due to its excellent stiffness, thermal stability and low density, silicon carbide (SiC) is an excellent candidate for fabrication of lightweight substrates for space mirrors in telescopes and satellites. However, the strong Si-C covalent bond induces high thermal stability and mechanical strength which makes it difficult to manufacture dense SiC. Other ceramic mirror materials such as Cordierite (CO720) by Kyocera® and Spodumene (ZERODUR®) by Schott® are characterized by their light weight, near zero thermal expansion coefficient and excellent thermal properties. However, mirrors made of cordierite or spodumene have relatively low stiffness and unsatisfactory thermal conductivity. We hypothesize that composites made of SiC-Cordierite and SiC-Spodumene can serve as better mirror substrates characterized by high stiffness, high thermal conductivity and improved thermomechanical stability. The present study reports on the synthesis and characterization of SiC-Cordierite (SiC-Cord) and SiC-Spodumene (SiC-Spod) using powder metallurgy method. The densification and thermomechanical stability of the SiC-mineral composites are enhanced by a novel in situ mineralization mechanism at the interface between the SiC and mineral binders between 800 °C and 1200 °C. The densities of SiC-Cord and SiC-Spod composites were 2.74 g/cc and 2.61 g/cc, respectively, while the thermal conductivities were 6.737 W/m. K and 3.281 W/m. K, respectively. Polishing the SiC-Cord with SiC grit numbers 400–1200 and diamond/silica slurry resulted in a mirror surface with an average roughness of 2.32 nm on SiC particles. The nano indentation stiffness of the polished SiC-Cordierite composite measured 239.9 ± 20.6 GPa. The stiffness of the SiC-Cord composite is superior to that of pure cordierite (140 GPa) or Zerodur (80 GPa). The average Vickers hardness of SiC-Cordierite was 8.12 ± 4.5 GPa which was superior to that of Zerodur (6.08 GPa) and comparable to that of pure cordierite (8–8.5 GPa). The composite samples demonstrated high thermal shock resistance as indicated by their comparable compressive strength and dimensional stability before and after quenching from 1200 °C to room temperature in water. Taken altogether, the superior thermomechanical properties of SiC-Cordierite and SiC-Spodumene suggest their suitability for mirrors in space-based telescopes.","PeriodicalId":146276,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123880337","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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