Abstract The joining techniques between carbon fiber reinforced polymer (CFRP) and metal are of great importance in many areas of structural mechanics where the optimization of weight, rigidity, and strength is a necessity (such as aeronautics, vehicles, energy generation, and biomechanics). As a result, several types of metal–composite joints have been manufactured using different methods, with the 3D metal anchor solution attracting significant attention. This study evaluates different anchor geometries applied to single lap joints through preliminary finite element method (FEM) simulations and experimental validation on joints between CFRP and Inconel 625 produced via a laser beam powder bed fusion (LB-PBF) additive process. The models proposed increase in complexity. The homogenization process is employed to determine the equivalent properties of the joint region that is occupied by metal anchors and CFRP. The model also supports topology parametrization to assess the impact of anchor geometry on structural properties. The study provides experimental validation of joint strength under tensile load for various anchoring surface topologies.
{"title":"Modeling and Experimental Validation of CFRP-Metal Joints Utilizing 3D Additively Manufactured Anchors","authors":"Giorgio De Pasquale, Antonio Coluccia","doi":"10.1115/1.4063110","DOIUrl":"https://doi.org/10.1115/1.4063110","url":null,"abstract":"Abstract The joining techniques between carbon fiber reinforced polymer (CFRP) and metal are of great importance in many areas of structural mechanics where the optimization of weight, rigidity, and strength is a necessity (such as aeronautics, vehicles, energy generation, and biomechanics). As a result, several types of metal–composite joints have been manufactured using different methods, with the 3D metal anchor solution attracting significant attention. This study evaluates different anchor geometries applied to single lap joints through preliminary finite element method (FEM) simulations and experimental validation on joints between CFRP and Inconel 625 produced via a laser beam powder bed fusion (LB-PBF) additive process. The models proposed increase in complexity. The homogenization process is employed to determine the equivalent properties of the joint region that is occupied by metal anchors and CFRP. The model also supports topology parametrization to assess the impact of anchor geometry on structural properties. The study provides experimental validation of joint strength under tensile load for various anchoring surface topologies.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136244258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenjun Xu, Siqi Feng, Bitao Yao, Zhenrui Ji, Zhihao Liu
Human-robot collaboration (HRC) combines the repeatability and strength of robots and human's ability of cognition and planning to enable a flexible and efficient production mode. The ideal HRC process is that robots can smoothly assist workers in complex environments. This means that robots need to know the process's turn-taking earlier, adapt to the operating habits of different workers, and make reasonable plans in advance to improve the fluency of HRC. However, many of the current HRC systems ignore the fluent turn-taking between robots and humans, which results in unsatisfactory HRC and affects productivity. Moreover, there are uncertainties in humans as different humans have different operating proficiency, resulting in different operating speeds. This requires the robots to be able to make early predictions of turn-taking even when human is uncertain. Therefore, in this paper, an early turn-taking prediction method in HRC assembly tasks with Izhi neuron model-based spiking neuron network (SNN) is proposed. On this basis, dynamic motion primitives (DMP) are used to establish trajectory templates at different operating speeds. The length of the sequence sent to the SNN network is judged by the matching degree between the observed data and the template, so as to adjust to human uncertainty. The proposed method is verified by the gear assembly case. The results show that our method can shorten the human-robot turn-taking recognition time under human uncertainty.
{"title":"Turn-taking prediction for human-robot collaborative assembly considering human uncertainty","authors":"Wenjun Xu, Siqi Feng, Bitao Yao, Zhenrui Ji, Zhihao Liu","doi":"10.1115/1.4063231","DOIUrl":"https://doi.org/10.1115/1.4063231","url":null,"abstract":"\u0000 Human-robot collaboration (HRC) combines the repeatability and strength of robots and human's ability of cognition and planning to enable a flexible and efficient production mode. The ideal HRC process is that robots can smoothly assist workers in complex environments. This means that robots need to know the process's turn-taking earlier, adapt to the operating habits of different workers, and make reasonable plans in advance to improve the fluency of HRC. However, many of the current HRC systems ignore the fluent turn-taking between robots and humans, which results in unsatisfactory HRC and affects productivity. Moreover, there are uncertainties in humans as different humans have different operating proficiency, resulting in different operating speeds. This requires the robots to be able to make early predictions of turn-taking even when human is uncertain. Therefore, in this paper, an early turn-taking prediction method in HRC assembly tasks with Izhi neuron model-based spiking neuron network (SNN) is proposed. On this basis, dynamic motion primitives (DMP) are used to establish trajectory templates at different operating speeds. The length of the sequence sent to the SNN network is judged by the matching degree between the observed data and the template, so as to adjust to human uncertainty. The proposed method is verified by the gear assembly case. The results show that our method can shorten the human-robot turn-taking recognition time under human uncertainty.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48689787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of Human-Robot Collaboration (HRC) in assembly tasks has gained increasing attention in recent years as it allows for the combination of the flexibility and dexterity of human operators with the repeatability of robots, thus meeting the demands of the current market. However, the performance of these collaborative systems is known to be influenced by various factors, including the complexity perceived by operators. This study aimed to investigate the effects of perceived complexity on the performance measures of HRC assembly. An experimental campaign was conducted in which a sample of skilled operators was instructed to perform six different variants of electronic boards and express a complexity assessment based on a set of assembly complexity criteria. Performance measures such as assembly time, in-process defects, quality control times, offline defects, total defects, and human stress response were monitored. The results of the study showed that the perceived complexity had a significant effect on assembly time, in-process and total defects, and human stress response, while no significant effect was found for offline defects and quality control times. Specifically, product variants perceived as more complex resulted in lower performance measures compared to products perceived as less complex. These findings hold important implications for the design and implementation of HRC assembly systems and suggest that perceived complexity should be taken into consideration to increase HRC performance.
{"title":"Exploring the effects of perceived complexity criteria on performance measures of human-robot collaborative assembly","authors":"E. Verna, Stefano Puttero, G. Genta, M. Galetto","doi":"10.1115/1.4063232","DOIUrl":"https://doi.org/10.1115/1.4063232","url":null,"abstract":"\u0000 The use of Human-Robot Collaboration (HRC) in assembly tasks has gained increasing attention in recent years as it allows for the combination of the flexibility and dexterity of human operators with the repeatability of robots, thus meeting the demands of the current market. However, the performance of these collaborative systems is known to be influenced by various factors, including the complexity perceived by operators. This study aimed to investigate the effects of perceived complexity on the performance measures of HRC assembly. An experimental campaign was conducted in which a sample of skilled operators was instructed to perform six different variants of electronic boards and express a complexity assessment based on a set of assembly complexity criteria. Performance measures such as assembly time, in-process defects, quality control times, offline defects, total defects, and human stress response were monitored. The results of the study showed that the perceived complexity had a significant effect on assembly time, in-process and total defects, and human stress response, while no significant effect was found for offline defects and quality control times. Specifically, product variants perceived as more complex resulted in lower performance measures compared to products perceived as less complex. These findings hold important implications for the design and implementation of HRC assembly systems and suggest that perceived complexity should be taken into consideration to increase HRC performance.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47350204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Partha Protim Mondal, Placid Ferreira, S. Kapoor, Patrick N. Bless
As a popular applied artificial intelligence tool, Bayesian networks are increasingly being used to model multistage manufacturing processes for fault diagnosis purposes. However, the major issue limiting the practical adoption of Bayesian networks is the difficulty of learning the network structure for large multistage processes. Traditionally, Bayesian network structures are learned either with the help of domain experts or by utilizing data-driven structure learning algorithms through trial and error. Both approaches have their limitations. On one hand, expert-driven approach is costly, time-consuming, cumbersome for large networks, susceptible to errors in assessing probabilities and on the other hand, data-driven approaches suffer from noise, biases, inadequacy of training data and often fail to capture the physical causal structure of the data. Therefore, in this paper, we propose a Bayesian network structure learning approach where popular manufacturing knowledge sources like the Failure Mode and Effect Analysis (FMEA) and hierarchical variable ordering are used as structural priors to guide the data-driven structure learning process. In addition, to introduce modularity and flexibility into the learning process, we present a sequential modeling approach for structure learning so that large multistage networks can be learned stage by stage progressively. Furthermore, through simulation studies, we compare and analyze the performance of the knowledge source based structurally-biased networks in the context of multistage process fault diagnosis.
{"title":"SEQUENTIAL MODELING AND KNOWLEDGE SOURCE INTEGRATION FOR IDENTIFYING THE STRUCTURE OF A BAYESIAN NETWORK FOR MULTISTAGE PROCESS MONITORING AND DIAGNOSIS","authors":"Partha Protim Mondal, Placid Ferreira, S. Kapoor, Patrick N. Bless","doi":"10.1115/1.4063235","DOIUrl":"https://doi.org/10.1115/1.4063235","url":null,"abstract":"\u0000 As a popular applied artificial intelligence tool, Bayesian networks are increasingly being used to model multistage manufacturing processes for fault diagnosis purposes. However, the major issue limiting the practical adoption of Bayesian networks is the difficulty of learning the network structure for large multistage processes. Traditionally, Bayesian network structures are learned either with the help of domain experts or by utilizing data-driven structure learning algorithms through trial and error. Both approaches have their limitations. On one hand, expert-driven approach is costly, time-consuming, cumbersome for large networks, susceptible to errors in assessing probabilities and on the other hand, data-driven approaches suffer from noise, biases, inadequacy of training data and often fail to capture the physical causal structure of the data. Therefore, in this paper, we propose a Bayesian network structure learning approach where popular manufacturing knowledge sources like the Failure Mode and Effect Analysis (FMEA) and hierarchical variable ordering are used as structural priors to guide the data-driven structure learning process. In addition, to introduce modularity and flexibility into the learning process, we present a sequential modeling approach for structure learning so that large multistage networks can be learned stage by stage progressively. Furthermore, through simulation studies, we compare and analyze the performance of the knowledge source based structurally-biased networks in the context of multistage process fault diagnosis.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41819234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article introduces a new control method for web tension control on a complex roll-to-roll winding machine used in battery production. Traditional web tension control method cannot perform well enough under high winding speed: the parameter tuning process is time-consuming, and the disturbance rejection performance is not satisfying, and the control performance is not stable. A hybrid control method is proposed, and it is easy to be implemented on common programming platform for commercial winding machines with an easy tuning process, while providing superior control performance to traditional control method. The system modeling used in the control method is much simpler than the modeling in most of tension control research, providing better feasibility for industrial application.
{"title":"Li-ion Battery Electrode Manufacturing Control System in Winding Process: Tension Control in Industrial Complex Roll-to-roll Winding Machine via SMC-FLC Hybrid Control Method","authors":"Haozhen Chen, J. Ni","doi":"10.1115/1.4063233","DOIUrl":"https://doi.org/10.1115/1.4063233","url":null,"abstract":"\u0000 This article introduces a new control method for web tension control on a complex roll-to-roll winding machine used in battery production. Traditional web tension control method cannot perform well enough under high winding speed: the parameter tuning process is time-consuming, and the disturbance rejection performance is not satisfying, and the control performance is not stable. A hybrid control method is proposed, and it is easy to be implemented on common programming platform for commercial winding machines with an easy tuning process, while providing superior control performance to traditional control method. The system modeling used in the control method is much simpler than the modeling in most of tension control research, providing better feasibility for industrial application.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45519793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Metamaterials are designed with intrinsic geometries to deliver unique properties, and recent years have witnessed an upsurge in leveraging additive manufacturing (AM) to produce metamaterials. However, the frequent occurrence of geometric defects in AM poses a critical obstacle to realizing the desired properties of fabricated metamaterials. Advances in three-dimensional (3D) scanning technologies enable the capture of fine-grained 3D geometric patterns, thereby providing a great opportunity for detecting geometric defects in fabricated metamaterials for property-oriented quality assurance. Realizing the full potential of 3D scanning-based quality control hinges largely on devising effective approaches to process scanned point clouds and extract geometric-pertinent information. In this study, a novel framework is developed to integrate recurrence network-based 3D geometry profiling with deep one-class learning for geometric defect detection in AM of metamaterials. First, we extend existing recurrence network models that focus on image data to representing 3D point clouds, by designing a new mechanism that characterizes points' geometric pattern affinities and spatial proximities. Then, a one-class graph neural network (GNN) approach is tailored to uncover topological variations of the recurrence network and detect anomalies that associated with geometric defects in the fabricated metamaterial. The developed methodology is evaluated through comprehensive simulated and real-world case studies. Experimental results have highlighted the efficacy of the developed methodology in identifying both global and local geometric defects in AM-fabricated metamaterials.
{"title":"Recurrence Network based 3D Geometry Representation Learning for Quality Control in Additive Manufacturing of Metamaterials","authors":"Yujing Yang, Chen Kan","doi":"10.1115/1.4063236","DOIUrl":"https://doi.org/10.1115/1.4063236","url":null,"abstract":"\u0000 Metamaterials are designed with intrinsic geometries to deliver unique properties, and recent years have witnessed an upsurge in leveraging additive manufacturing (AM) to produce metamaterials. However, the frequent occurrence of geometric defects in AM poses a critical obstacle to realizing the desired properties of fabricated metamaterials. Advances in three-dimensional (3D) scanning technologies enable the capture of fine-grained 3D geometric patterns, thereby providing a great opportunity for detecting geometric defects in fabricated metamaterials for property-oriented quality assurance. Realizing the full potential of 3D scanning-based quality control hinges largely on devising effective approaches to process scanned point clouds and extract geometric-pertinent information. In this study, a novel framework is developed to integrate recurrence network-based 3D geometry profiling with deep one-class learning for geometric defect detection in AM of metamaterials. First, we extend existing recurrence network models that focus on image data to representing 3D point clouds, by designing a new mechanism that characterizes points' geometric pattern affinities and spatial proximities. Then, a one-class graph neural network (GNN) approach is tailored to uncover topological variations of the recurrence network and detect anomalies that associated with geometric defects in the fabricated metamaterial. The developed methodology is evaluated through comprehensive simulated and real-world case studies. Experimental results have highlighted the efficacy of the developed methodology in identifying both global and local geometric defects in AM-fabricated metamaterials.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43993417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The new wave of Industry 4.0 is transforming manufacturing factories into data-rich environments. This provides an unprecedented opportunity to feed large amounts of sensing data collected from the physical factory into the construction of digital twin (DT) in cyberspace. However, little has been done to fully utilize the DT technology to improve the smartness and autonomous levels of small and medium-sized manufacturing factories. Indeed, only a small fraction of small and medium-sized manufacturers (SMMs) has considered implementing DT technology. There is an urgent need to exploit the full potential of data analytics and simulation-enabled DTs for advanced manufacturing. Hence, this paper presents the design and development of DT models for simulation optimization of manufacturing process flows. First, we develop a multi-agent simulation model that describes nonlinear and stochastic dynamics among a network of interactive manufacturing things, including customers, machines, automated guided vehicles (AGVs), queues, and jobs. Second, we propose a statistical metamodeling approach to design sequential computer experiments to optimize the utilization of AGV under uncertainty. Third, we construct two new graph models - job flow graph and AGV traveling graph - to track and monitor the real-time performance of manufacturing jobshops. The proposed simulation-enabled DT approach is evaluated and validated with experimental studies for the representation of a real-world manufacturing factory. Experimental results show that the proposed methodology effectively transforms a manufacturing jobshop into a new generation of DT-enabled smart factories.
{"title":"Digital Twinning and Optimization of Manufacturing Process Flows","authors":"Hankang Lee, Hui Yang","doi":"10.1115/1.4063234","DOIUrl":"https://doi.org/10.1115/1.4063234","url":null,"abstract":"\u0000 The new wave of Industry 4.0 is transforming manufacturing factories into data-rich environments. This provides an unprecedented opportunity to feed large amounts of sensing data collected from the physical factory into the construction of digital twin (DT) in cyberspace. However, little has been done to fully utilize the DT technology to improve the smartness and autonomous levels of small and medium-sized manufacturing factories. Indeed, only a small fraction of small and medium-sized manufacturers (SMMs) has considered implementing DT technology. There is an urgent need to exploit the full potential of data analytics and simulation-enabled DTs for advanced manufacturing. Hence, this paper presents the design and development of DT models for simulation optimization of manufacturing process flows. First, we develop a multi-agent simulation model that describes nonlinear and stochastic dynamics among a network of interactive manufacturing things, including customers, machines, automated guided vehicles (AGVs), queues, and jobs. Second, we propose a statistical metamodeling approach to design sequential computer experiments to optimize the utilization of AGV under uncertainty. Third, we construct two new graph models - job flow graph and AGV traveling graph - to track and monitor the real-time performance of manufacturing jobshops. The proposed simulation-enabled DT approach is evaluated and validated with experimental studies for the representation of a real-world manufacturing factory. Experimental results show that the proposed methodology effectively transforms a manufacturing jobshop into a new generation of DT-enabled smart factories.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43520609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiawei Wu, X. Tang, Shihao Xin, Chenyang Wang, F. Peng, R. Yan, Xinyong Mao
Robotic machining efficiency and accuracy are limited by milling vibration and chatter. Robot dynamic characteristics are strongly dependent on the poses; therefore, acquiring the robot dynamic characteristics in any pose is important for vibration suppression and chatter avoidance in large-range machining. This paper proposes an incremental self-excitation method for effectively identifying low-frequency frequency response functions (FRF) of milling robots. A fully knowable and controllable excitation increment can be achieved by attaching a mass block at the robot end, which overcomes the shortcoming of the traditional self-excitation methods that cannot obtain the dynamic compliance magnitude. With appropriate trajectory programming, this method can be carried out automatically in the poses of interest without manual operations. First, the impulse (moment) of the incremental self-excitation is modeled based on momentum theorem, and the association model of the pulse response increment with the incremental self-excitation is established. For the problem that the FRF calculation process is sensitive to noise, the incremental self-excitation is assumed to be a Gaussian pulse, and its identification method is provided. Then, the dimensionality requirement for identifying the 9-item (direct and cross) FRFs is reduced using the modal directionality of milling robots, and the corresponding FRF calculation method is proposed. The rationality of the required simplifications and assumptions of this method is verified by experiments and calculations. The experimental results in several robot poses show that the proposed method can effectively identify all the direct and cross FRFs in the low-frequency band.
{"title":"An incremental self-excitation method for effectively identifying low-frequency frequency response function of milling robots","authors":"Jiawei Wu, X. Tang, Shihao Xin, Chenyang Wang, F. Peng, R. Yan, Xinyong Mao","doi":"10.1115/1.4063155","DOIUrl":"https://doi.org/10.1115/1.4063155","url":null,"abstract":"\u0000 Robotic machining efficiency and accuracy are limited by milling vibration and chatter. Robot dynamic characteristics are strongly dependent on the poses; therefore, acquiring the robot dynamic characteristics in any pose is important for vibration suppression and chatter avoidance in large-range machining. This paper proposes an incremental self-excitation method for effectively identifying low-frequency frequency response functions (FRF) of milling robots. A fully knowable and controllable excitation increment can be achieved by attaching a mass block at the robot end, which overcomes the shortcoming of the traditional self-excitation methods that cannot obtain the dynamic compliance magnitude. With appropriate trajectory programming, this method can be carried out automatically in the poses of interest without manual operations. First, the impulse (moment) of the incremental self-excitation is modeled based on momentum theorem, and the association model of the pulse response increment with the incremental self-excitation is established. For the problem that the FRF calculation process is sensitive to noise, the incremental self-excitation is assumed to be a Gaussian pulse, and its identification method is provided. Then, the dimensionality requirement for identifying the 9-item (direct and cross) FRFs is reduced using the modal directionality of milling robots, and the corresponding FRF calculation method is proposed. The rationality of the required simplifications and assumptions of this method is verified by experiments and calculations. The experimental results in several robot poses show that the proposed method can effectively identify all the direct and cross FRFs in the low-frequency band.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":"86 ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41310216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
3D-printed blocks with drop coating could work as diffraction gratings while the layer stepping serves as the grooves of the gratings. The paper reports 3D-printed diffraction gratings coated with different resins. A collimated laser with a wavelength of 520 nm passed through the gratings and generated diffraction patterns. Optical path differences and surface profiles of the samples were measured to analyze the mechanism of the diffraction phenomenon. The as-printed samples had a grating height of about 8 μm induced by layer stepping, which could not generate clear diffraction patterns because of too large optical path difference. After being coated with different resins on the surfaces, the printed samples generated diffraction patterns. We experimentally showed that the magnitude of optical path differences became close to the wavelength of the laser and that the diffraction phenomenon was mainly caused by the difference in the refractive indices between the as-printed part and the drop-coated part. This novel method enables low-cost 3D printers to fabricate diffractive optical elements for visible light.
{"title":"3D PRINTED DIFFRACTION GRATINGS DROP COATED BY DIFFERENT RESINS AND THEIR MECHANISM","authors":"Junyu Hua, Yujie Shan, Shaocheng Wu, Huachao Mao","doi":"10.1115/1.4063137","DOIUrl":"https://doi.org/10.1115/1.4063137","url":null,"abstract":"\u0000 3D-printed blocks with drop coating could work as diffraction gratings while the layer stepping serves as the grooves of the gratings. The paper reports 3D-printed diffraction gratings coated with different resins. A collimated laser with a wavelength of 520 nm passed through the gratings and generated diffraction patterns. Optical path differences and surface profiles of the samples were measured to analyze the mechanism of the diffraction phenomenon. The as-printed samples had a grating height of about 8 μm induced by layer stepping, which could not generate clear diffraction patterns because of too large optical path difference. After being coated with different resins on the surfaces, the printed samples generated diffraction patterns. We experimentally showed that the magnitude of optical path differences became close to the wavelength of the laser and that the diffraction phenomenon was mainly caused by the difference in the refractive indices between the as-printed part and the drop-coated part. This novel method enables low-cost 3D printers to fabricate diffractive optical elements for visible light.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43049295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advancements of additive manufacturing enable fabrication of in vitro biomimetic grafts leveraging biological materials and cells for various biomedical applications. The realization of such biofabrication typically requires time from minutes to hours depending on the scale and complexity of the models. During direct biofabrication, cell sedimentation with the resultant aggregation is extensively deemed to be one of the acute problems for precise and reliable inkjet-based bioprinting. It often results in highly unstable droplet formation, nozzle clogging, and non-uniformity of post-printing cell distribution. Our previous study has implemented active bioink circulation to mitigate cell sedimentation and aggregation within the bioink reservoir. This study focuses on the comparison of post-printing cell distribution within formed microspheres and one-layer sheets with and without active circulation. The experimental results have demonstrated the significant improvement in post-printing cell distribution under implemented active circulation. Moreover, the printed sheet samples are subject to 3-day incubation to investigate the effect of cell distribution on cell viability and proliferation. It shows that compared to non-uniform cell distribution the uniform cell distribution significantly improves cell viability (92% vs 77% at Day 3) and cell proliferation (3.3 times vs 1.7 times at Day 3). The preliminary results in this letter have demonstrated not only the high effectiveness of the active bioink circulation to improve post-printing cell distribution within microspheres and one-layer sheets, but also the critical role of the uniform post-printing cell distribution in promoting cell viability and proliferation.
{"title":"Improving Uniformity of Cell Distribution in Post-Inkjet-Based Bioprinting","authors":"Jiachen Liu, Changxue Xu","doi":"10.1115/1.4063134","DOIUrl":"https://doi.org/10.1115/1.4063134","url":null,"abstract":"\u0000 Advancements of additive manufacturing enable fabrication of in vitro biomimetic grafts leveraging biological materials and cells for various biomedical applications. The realization of such biofabrication typically requires time from minutes to hours depending on the scale and complexity of the models. During direct biofabrication, cell sedimentation with the resultant aggregation is extensively deemed to be one of the acute problems for precise and reliable inkjet-based bioprinting. It often results in highly unstable droplet formation, nozzle clogging, and non-uniformity of post-printing cell distribution. Our previous study has implemented active bioink circulation to mitigate cell sedimentation and aggregation within the bioink reservoir. This study focuses on the comparison of post-printing cell distribution within formed microspheres and one-layer sheets with and without active circulation. The experimental results have demonstrated the significant improvement in post-printing cell distribution under implemented active circulation. Moreover, the printed sheet samples are subject to 3-day incubation to investigate the effect of cell distribution on cell viability and proliferation. It shows that compared to non-uniform cell distribution the uniform cell distribution significantly improves cell viability (92% vs 77% at Day 3) and cell proliferation (3.3 times vs 1.7 times at Day 3). The preliminary results in this letter have demonstrated not only the high effectiveness of the active bioink circulation to improve post-printing cell distribution within microspheres and one-layer sheets, but also the critical role of the uniform post-printing cell distribution in promoting cell viability and proliferation.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43160196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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