Mohammad Khairul Habib Pulok, Pratik Sarker, U. Chakravarty
Dielectric elastomer membranes are a category of electroactive polymers composed of a thin elastomer film sandwiched between two compliant electrodes. An electrostatic pressure is created when there is an externally applied voltage on the electrodes which creates compression in the thickness direction and extension in the in-plane direction. This outlines a variation of the tension in the membrane that can be used to change its dynamic behavior. In this study, a specimen of an electroactive membrane, VHB 4910 is considered to observe the aerodynamic characteristics under external flow of air. Both experimental and numerical analyses are performed to predict the fluid-structure interaction behavior of the specimen for different angles of attack. A vibration testing arrangement is used to estimate the resonance frequencies and the mode shapes which are validated by the finite element results. From the study, the coefficient of lift is found to increase with the angle of attack up to a critical value. Similarly, the coefficient of drag increases with the angle of attack. Both lift and drag coefficients decrease with the Reynolds number. The magnitudes of the natural frequencies decrease as the applied voltages rise. The natural frequencies and mode shapes of the membrane can be tuned by changing the pretension, the pressure, and/or the voltage.
{"title":"An Analysis of the Aerodynamic Response of an Electroactive Membrane","authors":"Mohammad Khairul Habib Pulok, Pratik Sarker, U. Chakravarty","doi":"10.1115/imece2019-11455","DOIUrl":"https://doi.org/10.1115/imece2019-11455","url":null,"abstract":"\u0000 Dielectric elastomer membranes are a category of electroactive polymers composed of a thin elastomer film sandwiched between two compliant electrodes. An electrostatic pressure is created when there is an externally applied voltage on the electrodes which creates compression in the thickness direction and extension in the in-plane direction. This outlines a variation of the tension in the membrane that can be used to change its dynamic behavior. In this study, a specimen of an electroactive membrane, VHB 4910 is considered to observe the aerodynamic characteristics under external flow of air. Both experimental and numerical analyses are performed to predict the fluid-structure interaction behavior of the specimen for different angles of attack. A vibration testing arrangement is used to estimate the resonance frequencies and the mode shapes which are validated by the finite element results. From the study, the coefficient of lift is found to increase with the angle of attack up to a critical value. Similarly, the coefficient of drag increases with the angle of attack. Both lift and drag coefficients decrease with the Reynolds number. The magnitudes of the natural frequencies decrease as the applied voltages rise. The natural frequencies and mode shapes of the membrane can be tuned by changing the pretension, the pressure, and/or the voltage.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134154405","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 design and analysis of a paper-based microfluidic analytical device (μPAD) are presented in this paper for the detection of fentanyl and related synthetic opioids. Fentanyl, a synthetic opioid, is an extremely fast-acting synthetic narcotic analgesic having a high potency of approximately 100 to 200 times that of morphine. Detection of fentanyl can be done by colorimetric assays, i.e., spot tests with paper strips and μPADs which offer speed, simplicity of operation, portability, and affordability. The microfluidic behavior of liquid specimen and paper in the μPADs and test strips play a significant role in drug detection methods. Therefore, the study contains the fabrication of the test device using 3D printing and analysis of microfluidic behavior of the paper-based fentanyl test device. A multiphase computational fluid dynamics (CFD) model of a 3D microchannel is developed to evaluate the microfluidic properties. The CFD model incorporates the properties of cellulose and fentanyl solution to determine the flow parameters using the volume of fluid method. Wicking in the cellulose paper is studied analytically considering the Lucas-Washburn equation and Darcy’s law. Experiments with the fabricated μPAD and commercial test-kit samples are also conducted to compare the experimental results with the results for the flow parameters found from the numerical simulation.
{"title":"Characterizations of the Paper-Based Microfluidic Devices Used for Detecting Fentanyl and Related Synthetic Opioids","authors":"M. S. Rahman, U. Chakravarty","doi":"10.1115/imece2019-11581","DOIUrl":"https://doi.org/10.1115/imece2019-11581","url":null,"abstract":"\u0000 The design and analysis of a paper-based microfluidic analytical device (μPAD) are presented in this paper for the detection of fentanyl and related synthetic opioids. Fentanyl, a synthetic opioid, is an extremely fast-acting synthetic narcotic analgesic having a high potency of approximately 100 to 200 times that of morphine. Detection of fentanyl can be done by colorimetric assays, i.e., spot tests with paper strips and μPADs which offer speed, simplicity of operation, portability, and affordability. The microfluidic behavior of liquid specimen and paper in the μPADs and test strips play a significant role in drug detection methods. Therefore, the study contains the fabrication of the test device using 3D printing and analysis of microfluidic behavior of the paper-based fentanyl test device. A multiphase computational fluid dynamics (CFD) model of a 3D microchannel is developed to evaluate the microfluidic properties. The CFD model incorporates the properties of cellulose and fentanyl solution to determine the flow parameters using the volume of fluid method. Wicking in the cellulose paper is studied analytically considering the Lucas-Washburn equation and Darcy’s law. Experiments with the fabricated μPAD and commercial test-kit samples are also conducted to compare the experimental results with the results for the flow parameters found from the numerical simulation.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131634403","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}
This paper addresses the hygroscopic effects on the impact response of specially-orthotropic carbon fiber reinforced polymer composite plates under low-velocity impact loading. The material used in this study is Toray T800/3900 which is consist of carbon fibers and epoxy resin. For different percentage of moisture content by weight in the composite plates, low-velocity impact tests were done by using the 8-ply unidirectional [UD] and cross-ply [CP] composite plates with newly designed mini-drop tower testing machine. To study the hygroscopic effects, specimens were impacted by constant weight of impactor (3.44 Kg) with fixed impact height of 0.70 m corresponding to 23.62 J impact energy. The experiments were carried out on plates with dimension of 125 mm × 125 mm × 1.5 mm for simply supported boundary conditions. All UD composite plates were broken into two parts, but the impactor bounces back after hitting the top layer of the CP composite plate for all conditions. The strength of the UD composite plates decreased with increase of moisture contents, but with the increased of moisture contents, a small change was observed in the peak force, time to peak force values and absorbed energy for the CP composite plates. The large size damage areas were observed for wet plates as compared to dry plates. Absorbed moisture contents also have effect on the impactor velocity and impactor displacement.
研究了低速冲击载荷下吸湿性对特殊正交异性碳纤维增强聚合物复合材料板冲击响应的影响。本研究使用的材料是东丽T800/3900，由碳纤维和环氧树脂组成。采用新设计的微型落塔试验机，对8层单向复合材料(UD)和交叉复合材料(CP)进行了不同重量含水率的低速冲击试验。为研究吸湿效应，采用定重(3.44 Kg)冲击器冲击试件，固定冲击高度0.70 m，对应23.62 J冲击能量。实验在尺寸为125 mm × 125 mm × 1.5 mm的板上进行，边界条件为简支。所有UD复合板都被分成两部分，但在所有情况下，冲击器都在撞击CP复合板的顶层后反弹回来。UD复合材料板的强度随含水率的增加而降低，而CP复合材料板的峰值力、峰值力值和吸收能量随含水率的增加变化不大。与干板相比，湿板观察到较大尺寸的损伤区域。吸湿量对冲击器速度和位移也有影响。
{"title":"Effects of Absorbed Moisture Content on the Impact Response of Specially-Orthotropic Composite Plates","authors":"F. Ahmad, F. Abbassi, S. Miran","doi":"10.1115/imece2019-12221","DOIUrl":"https://doi.org/10.1115/imece2019-12221","url":null,"abstract":"\u0000 This paper addresses the hygroscopic effects on the impact response of specially-orthotropic carbon fiber reinforced polymer composite plates under low-velocity impact loading. The material used in this study is Toray T800/3900 which is consist of carbon fibers and epoxy resin. For different percentage of moisture content by weight in the composite plates, low-velocity impact tests were done by using the 8-ply unidirectional [UD] and cross-ply [CP] composite plates with newly designed mini-drop tower testing machine. To study the hygroscopic effects, specimens were impacted by constant weight of impactor (3.44 Kg) with fixed impact height of 0.70 m corresponding to 23.62 J impact energy. The experiments were carried out on plates with dimension of 125 mm × 125 mm × 1.5 mm for simply supported boundary conditions. All UD composite plates were broken into two parts, but the impactor bounces back after hitting the top layer of the CP composite plate for all conditions. The strength of the UD composite plates decreased with increase of moisture contents, but with the increased of moisture contents, a small change was observed in the peak force, time to peak force values and absorbed energy for the CP composite plates. The large size damage areas were observed for wet plates as compared to dry plates. Absorbed moisture contents also have effect on the impactor velocity and impactor displacement.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131636808","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}
A. Bertolino, A. D. Martin, G. Jacazio, S. Mauro, M. Sorli
Over the last two decades, one of the most prominent research themes in the aerospace community involved the definition of “more electric aircrafts”. For flight control systems the trend is to replace the traditional electro-hydraulic solution with electro-mechanical actuators. However, safety issues severely hinder the diffusion of this technology. A possible breakthrough in this field can be the development of robust PHM techniques to anticipate the occurrence of failures. Ball screws feature one of the highest failure rate within EMAs’ mechanical components. Since their accurate modeling is fairly complex, experimental results are needed to support simulation outcomes to help in the definition of reliable health monitoring schemes. This paper presents the model-based design of a novel test bench intended for PHM analyses of ball screw drives. At first the test bench layout is introduced and compared to the state of the art. A high-fidelity model of the test bench is presented and exploited to perform a Monte Carlo simulation campaign with the goal to characterize its behavior versus measure and process noise in presence of varying size backlash. Finally, a test procedure for backlash identification is defined.
{"title":"Robust Design of a Test Bench for PHM Study of Ball Screw Drives","authors":"A. Bertolino, A. D. Martin, G. Jacazio, S. Mauro, M. Sorli","doi":"10.1115/imece2019-10713","DOIUrl":"https://doi.org/10.1115/imece2019-10713","url":null,"abstract":"\u0000 Over the last two decades, one of the most prominent research themes in the aerospace community involved the definition of “more electric aircrafts”. For flight control systems the trend is to replace the traditional electro-hydraulic solution with electro-mechanical actuators. However, safety issues severely hinder the diffusion of this technology. A possible breakthrough in this field can be the development of robust PHM techniques to anticipate the occurrence of failures.\u0000 Ball screws feature one of the highest failure rate within EMAs’ mechanical components. Since their accurate modeling is fairly complex, experimental results are needed to support simulation outcomes to help in the definition of reliable health monitoring schemes.\u0000 This paper presents the model-based design of a novel test bench intended for PHM analyses of ball screw drives. At first the test bench layout is introduced and compared to the state of the art. A high-fidelity model of the test bench is presented and exploited to perform a Monte Carlo simulation campaign with the goal to characterize its behavior versus measure and process noise in presence of varying size backlash. Finally, a test procedure for backlash identification is defined.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121351608","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}
With the emphasis on lightweighting, composites are being turned to help reduce weight while still maintaining strength and stiffness. However, composites tend to be linear elastic to failure so there is often no warning of failure unlike in metallic components. For this research, a pipe section was fabricated from an Inconel 718 liner with a carbon composite overwrap. The pipe was then subjected to increasing internal pressure until failure. The results from this experiment were used to assist in the creation and validation of a finite element model of the experiment. The model makes use of advanced numerical techniques to predict when failure will occur. This paper will present the fabrication, testing and modeling of this effort.
{"title":"Composite Overwrapped Pipe Burst Test: Modeling and Experimentation","authors":"A. Littlefield, Lucas B. Smith, M. Macri, J. Root","doi":"10.1115/imece2019-10387","DOIUrl":"https://doi.org/10.1115/imece2019-10387","url":null,"abstract":"\u0000 With the emphasis on lightweighting, composites are being turned to help reduce weight while still maintaining strength and stiffness. However, composites tend to be linear elastic to failure so there is often no warning of failure unlike in metallic components. For this research, a pipe section was fabricated from an Inconel 718 liner with a carbon composite overwrap. The pipe was then subjected to increasing internal pressure until failure. The results from this experiment were used to assist in the creation and validation of a finite element model of the experiment. The model makes use of advanced numerical techniques to predict when failure will occur. This paper will present the fabrication, testing and modeling of this effort.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125850166","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}
Tungsten heavy alloys (WHAs) are ideally suited to a wide range of density applications such as counterweights, inertial masses, radiation shielding, sporting goods and ordnance products. Manufacturing of these components essentially require machining to achieve desired finish, dimensions and tolerances However, machining of WHAs are extremely challenging because of higher values of elastic stiffness and hardness. Hence, there is a need to find the right combination of cutting parameters to carry out the machining operations efficiently. In the present work, turning tests are conducted on three different grades of WHAs, namely, 90WHA, 95WHA and 97WHA. Taguchi analysis is carried out to find out the most contributing factor as well as optimum cutting parameters that can give higher metal removal rate (MRR), lower surface roughness and lower cutting forces. It is observed that feed rate is the most prominent factor with percentage contribution varying in the range of 46–61%; whereas cutting speed has least effect on cutting forces, especially for 95WHA and 97WHA. Optimum values of forces, surface roughness and MRR and the corresponding machining parameters to be taken are presented. It is observed that 95W WHA has slightly better machinability as compared to other two grades since it gives highest MRR with lowest cutting forces and surface roughness values. The optimum machining parameter settings, so predicted, can be utilized to machine WHAs efficiently for manufacture of counter weights and inertial masses used in aerospace applications.
{"title":"Optimization of Machining Parameters During Turning of Tungsten Heavy Alloys Using Taguchi Analysis","authors":"C. Sagar, A. Priyadarshini, A. Gupta","doi":"10.1115/imece2019-10958","DOIUrl":"https://doi.org/10.1115/imece2019-10958","url":null,"abstract":"\u0000 Tungsten heavy alloys (WHAs) are ideally suited to a wide range of density applications such as counterweights, inertial masses, radiation shielding, sporting goods and ordnance products. Manufacturing of these components essentially require machining to achieve desired finish, dimensions and tolerances However, machining of WHAs are extremely challenging because of higher values of elastic stiffness and hardness. Hence, there is a need to find the right combination of cutting parameters to carry out the machining operations efficiently. In the present work, turning tests are conducted on three different grades of WHAs, namely, 90WHA, 95WHA and 97WHA. Taguchi analysis is carried out to find out the most contributing factor as well as optimum cutting parameters that can give higher metal removal rate (MRR), lower surface roughness and lower cutting forces. It is observed that feed rate is the most prominent factor with percentage contribution varying in the range of 46–61%; whereas cutting speed has least effect on cutting forces, especially for 95WHA and 97WHA. Optimum values of forces, surface roughness and MRR and the corresponding machining parameters to be taken are presented. It is observed that 95W WHA has slightly better machinability as compared to other two grades since it gives highest MRR with lowest cutting forces and surface roughness values. The optimum machining parameter settings, so predicted, can be utilized to machine WHAs efficiently for manufacture of counter weights and inertial masses used in aerospace applications.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127881899","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}
Z. Huai, Ming Zhang, Yu Zhu, Chen Anlin, Xin Li, Wang Leijie
The electrodynamic reaction sphere is a novel actuator for the spacecraft attitude control subsystem. This paper proposes a neural network inverse based decoupling control scheme to actualize the omnidirectional rotation of the electrodynamic reaction sphere which has strong multivariable nonlinear coupling features due to the induction-based drive. And an integrated electromagnetic torque model of the reaction sphere is firstly derived from the electromagnetic field analysis and modified with the finite element analysis method. Then based on the integrated torque model, a back propagation feedforward neural network is constructed and trained to approach the inverse dynamics which transforms the original system into a pseudo-linear system. Furthermore, an additional PI controller is introduced to achieve good control performance against the unmodelled dynamics. Finally, the effectiveness of the proposed method is validated by simulations.
{"title":"Neural Network Inverse Based Omnidirectional Rotation Decoupling Control to the Electrodynamic Reaction Sphere","authors":"Z. Huai, Ming Zhang, Yu Zhu, Chen Anlin, Xin Li, Wang Leijie","doi":"10.1115/imece2019-11129","DOIUrl":"https://doi.org/10.1115/imece2019-11129","url":null,"abstract":"\u0000 The electrodynamic reaction sphere is a novel actuator for the spacecraft attitude control subsystem. This paper proposes a neural network inverse based decoupling control scheme to actualize the omnidirectional rotation of the electrodynamic reaction sphere which has strong multivariable nonlinear coupling features due to the induction-based drive. And an integrated electromagnetic torque model of the reaction sphere is firstly derived from the electromagnetic field analysis and modified with the finite element analysis method. Then based on the integrated torque model, a back propagation feedforward neural network is constructed and trained to approach the inverse dynamics which transforms the original system into a pseudo-linear system. Furthermore, an additional PI controller is introduced to achieve good control performance against the unmodelled dynamics. Finally, the effectiveness of the proposed method is validated by simulations.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114891612","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}
Percussive riveting is a dependable assembly method that produces high-quality joints in the aerospace industry. Its successful application is derived from its ease to implement in an assembly floor environment. The rivets are formed on the shank end of the rivet using a forming tool like a bucking bar and the head is constrained and impacted with a rapid succession of hits using a pneumatic gun with a special purpose die head. The rivet forms an interference fit joint because of the residual compressive stresses that are set up in the circumferential direction due to plastic flow of rivet material. These compressive stresses are balanced by tensile stresses in the skin and stiffener bulk material. Compressive stresses in the longitudinal direction help keep the skins pressed together. Research studies focused on the dynamics modeling of the percussive riveting process for robotic automation have not delivered an understanding of the temporal evolution of stress and strain fields in the vicinity of the rivet and the rivet hole. These studies aimed to produce joints of equal strength using automated assembly process compared with the manual assembly process. No modeling efforts have been published up to this point in time. This understanding is important in order to produce joints of predictable strength. A simulation effort for an unstiffened percussive riveting stackup assembly will be undertaken to study the trends of beneficial compressive residual stresses and strains within the bucked rivet. It is our goal to eventually estimate joint strength for prescribed sets of joint assembly parameters. The domain of interest will be restricted to few inches from the rivet axis.
{"title":"Numerical Study of the Percussive Riveting Process: Initial Results","authors":"S. Krovvidi, M. Ramulu, P. Reinhall","doi":"10.1115/imece2019-11544","DOIUrl":"https://doi.org/10.1115/imece2019-11544","url":null,"abstract":"\u0000 Percussive riveting is a dependable assembly method that produces high-quality joints in the aerospace industry. Its successful application is derived from its ease to implement in an assembly floor environment. The rivets are formed on the shank end of the rivet using a forming tool like a bucking bar and the head is constrained and impacted with a rapid succession of hits using a pneumatic gun with a special purpose die head. The rivet forms an interference fit joint because of the residual compressive stresses that are set up in the circumferential direction due to plastic flow of rivet material. These compressive stresses are balanced by tensile stresses in the skin and stiffener bulk material. Compressive stresses in the longitudinal direction help keep the skins pressed together. Research studies focused on the dynamics modeling of the percussive riveting process for robotic automation have not delivered an understanding of the temporal evolution of stress and strain fields in the vicinity of the rivet and the rivet hole. These studies aimed to produce joints of equal strength using automated assembly process compared with the manual assembly process. No modeling efforts have been published up to this point in time. This understanding is important in order to produce joints of predictable strength. A simulation effort for an unstiffened percussive riveting stackup assembly will be undertaken to study the trends of beneficial compressive residual stresses and strains within the bucked rivet. It is our goal to eventually estimate joint strength for prescribed sets of joint assembly parameters. The domain of interest will be restricted to few inches from the rivet axis.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133232122","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}
An advanced shell finite element with a variable kinematic field based on a new zig-zag power function is proposed for the analysis of sandwich shell structures. The kinematic field is written by using an arbitrary number of continuous piecewise polynomial functions. The polynomial expansion order of a generic subdomain is a combination of zig-zag power functions depending on the shell thickness coordinate. As in the classical layer-wise approach, the shell thickness can be divided into a variable number of mathematical subdomains. The expansion order of each subdomain is an input parameter of the analysis. This feature enables the solution to be locally refined over generic regions of the shell thickness by enriching the kinematic field. The advanced finite shell elements with variable kinematics are formulated in the framework of the Carrera Unified Formulation. The finite element arrays are formulated in terms of fundamental nuclei, which are invariants of the theory approximation order and the modelling technique (Equivalent-Single-Layer, Layer-Wise). In this work, the attention is focused on linear static stress analysis and the free-vibration analysis of sandwich shell structures.
{"title":"Higher-Order Shell Element for the Static and Free-Vibration Analysis of Sandwich Structures","authors":"E. Carrera, S. Valvano, M. Filippi","doi":"10.1115/IMECE2018-86784","DOIUrl":"https://doi.org/10.1115/IMECE2018-86784","url":null,"abstract":"An advanced shell finite element with a variable kinematic field based on a new zig-zag power function is proposed for the analysis of sandwich shell structures. The kinematic field is written by using an arbitrary number of continuous piecewise polynomial functions. The polynomial expansion order of a generic subdomain is a combination of zig-zag power functions depending on the shell thickness coordinate. As in the classical layer-wise approach, the shell thickness can be divided into a variable number of mathematical subdomains. The expansion order of each subdomain is an input parameter of the analysis. This feature enables the solution to be locally refined over generic regions of the shell thickness by enriching the kinematic field. The advanced finite shell elements with variable kinematics are formulated in the framework of the Carrera Unified Formulation. The finite element arrays are formulated in terms of fundamental nuclei, which are invariants of the theory approximation order and the modelling technique (Equivalent-Single-Layer, Layer-Wise). In this work, the attention is focused on linear static stress analysis and the free-vibration analysis of sandwich shell structures.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123001188","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}
Farid Miah, Emmanuel De-Luycker, F. Lachaud, Y. Landon, R. Piquet
The necessity of understanding the influence of cutting variables in orthogonal cutting of Carbon Fiber Reinforced Polymer (CFRP) is vital because of their significant influences to the quality of manufactured parts. In this present research work the influences of different cutting depths to the cutting and thrust forces have been analyzed and a comparison between an equivalent homogeneous material (EHM) macro-model and experimental results have been made. The reasons of the beginning high cutting and thrust forces have been studied and explained. The post analysis of the experimental machined surfaces has been done to analyze the generated surface roughness and fiber-matrix interface crack generation. Five different cutting depths and four individual fiber orientations have been tested both numerically and experimentally. Significant influence of cutting depths to the cutting force has been found and the surface quality of newly generated machined part is discovered as a function of cutting depth and fiber orientation.
{"title":"Effect of Different Cutting Depths to the Cutting Forces and Machining Quality of CFRP Parts in Orthogonal Cutting: A Numerical and Experimental Comparison","authors":"Farid Miah, Emmanuel De-Luycker, F. Lachaud, Y. Landon, R. Piquet","doi":"10.1115/IMECE2018-87008","DOIUrl":"https://doi.org/10.1115/IMECE2018-87008","url":null,"abstract":"The necessity of understanding the influence of cutting variables in orthogonal cutting of Carbon Fiber Reinforced Polymer (CFRP) is vital because of their significant influences to the quality of manufactured parts. In this present research work the influences of different cutting depths to the cutting and thrust forces have been analyzed and a comparison between an equivalent homogeneous material (EHM) macro-model and experimental results have been made. The reasons of the beginning high cutting and thrust forces have been studied and explained. The post analysis of the experimental machined surfaces has been done to analyze the generated surface roughness and fiber-matrix interface crack generation. Five different cutting depths and four individual fiber orientations have been tested both numerically and experimentally. Significant influence of cutting depths to the cutting force has been found and the surface quality of newly generated machined part is discovered as a function of cutting depth and fiber orientation.","PeriodicalId":119220,"journal":{"name":"Volume 1: Advances in Aerospace Technology","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115007599","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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