Reinforced PPS thermoplastics exposed to variations in temperature and humidity are subject to aging and interface degradation. These phenomena can lead to ruptures due to the interphase weakening. In this study, a micromechanical model based on the equivalent inclusion model is implemented using the viscoelastic behaviours of the neat and aged grades identified by spectrometric analyses. The presented coated inclusion model allows to extract the viscoelastic behavior of the interphase in the dry-as-molded composite and in the aged composite by inverse method conducted for viscoelastic behavior. The presence of the interphase testifies to the degradation of the thermomechanical properties in the vicinity of the reinforcements. In the aged composite, the interphase also undergoes an aging phenomenon. Thus, the model compares the behavior of the interphase in the dry-as-molded and aged grades of the composite and separates the effects linked to the degradation of adhesion of the fibers from the effects linked to specific hydroscopic aging.
{"title":"On the thermo-visco-elastic behaviour of neat and aged PPS composites","authors":"Quentin C.P. Bourgogne , Vanessa Bouchart , Pierre Chevrier , Florence Dinzart","doi":"10.1016/j.ijmecsci.2024.109761","DOIUrl":"10.1016/j.ijmecsci.2024.109761","url":null,"abstract":"<div><div>Reinforced PPS thermoplastics exposed to variations in temperature and humidity are subject to aging and interface degradation. These phenomena can lead to ruptures due to the interphase weakening. In this study, a micromechanical model based on the equivalent inclusion model is implemented using the viscoelastic behaviours of the neat and aged grades identified by spectrometric analyses. The presented coated inclusion model allows to extract the viscoelastic behavior of the interphase in the dry-as-molded composite and in the aged composite by inverse method conducted for viscoelastic behavior. The presence of the interphase testifies to the degradation of the thermomechanical properties in the vicinity of the reinforcements. In the aged composite, the interphase also undergoes an aging phenomenon. Thus, the model compares the behavior of the interphase in the dry-as-molded and aged grades of the composite and separates the effects linked to the degradation of adhesion of the fibers from the effects linked to specific hydroscopic aging.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109761"},"PeriodicalIF":7.1,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.ijmecsci.2024.109767
Xuebin Zhang , Jun Zhang , Tao Liu , Junjie Rong , Liming Chen , Ning Hu
Elastic metamaterials favor the wide bandgap generation, but their formation mechanisms impose certain constraints on the achievable locations and widths. To overcome this limitation, this study proposes an innovative method that optimizes specific passbands and subsequently transforms them into bandgaps through an external stimulus. As an illustration, two meta-beams with different third passbands are optimized. In addition, to examine the formation and transformation mechanisms of the optimized passbands, this study develops several meta-beam models, incorporating force neutralizers, moment neutralizers, and their hybrid combinations, which are modally equivalent to the optimized unit cells. Samples for the two optimized meta-beams are fabricated using a three-dimensional printing technique. The experimental measurements are conducted at both room temperature and elevated temperatures, and the results confirm that when the temperature increases to approximately 60 °C, the optimized third passbands transform into bandgaps. Furthermore, repeated thermal loading cycles substantiate the reversibility of this transformation, demonstrating a promising application potential of the proposed method to tunable broadband meta-beam designs.
{"title":"Transformative elastic metamaterials: Temperature-induced passband-to-bandgap conversion","authors":"Xuebin Zhang , Jun Zhang , Tao Liu , Junjie Rong , Liming Chen , Ning Hu","doi":"10.1016/j.ijmecsci.2024.109767","DOIUrl":"10.1016/j.ijmecsci.2024.109767","url":null,"abstract":"<div><div>Elastic metamaterials favor the wide bandgap generation, but their formation mechanisms impose certain constraints on the achievable locations and widths. To overcome this limitation, this study proposes an innovative method that optimizes specific passbands and subsequently transforms them into bandgaps through an external stimulus. As an illustration, two meta-beams with different third passbands are optimized. In addition, to examine the formation and transformation mechanisms of the optimized passbands, this study develops several meta-beam models, incorporating force neutralizers, moment neutralizers, and their hybrid combinations, which are modally equivalent to the optimized unit cells. Samples for the two optimized meta-beams are fabricated using a three-dimensional printing technique. The experimental measurements are conducted at both room temperature and elevated temperatures, and the results confirm that when the temperature increases to approximately 60 °C, the optimized third passbands transform into bandgaps. Furthermore, repeated thermal loading cycles substantiate the reversibility of this transformation, demonstrating a promising application potential of the proposed method to tunable broadband meta-beam designs.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109767"},"PeriodicalIF":7.1,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.ijmecsci.2024.109757
Fangxing Wu , Xiaobo Fan , Guang Yang , Xianshuo Chen , Shijian Yuan
Cryogenic forming has been developed to manufacture thin-walled curved aluminum alloy components, whose final dimensions are affected by cryogenic shrinkage and springback. Therefore, dimensional changes of spherical shell in cryogenic forming were studied theoretically and experimentally. The cryogenic forming process was discussed to elucidate the factors affecting the dimensional change. The stress distribution was analyzed to qualitatively reveal the springback behavior. Cryogenic dimensional measurement devices were built to quantitatively evaluate the dimensional changes in the forming processes of punch cooling, springback, and specimen restoration to room temperature. The temperature dependencies of the elastic modulus and expansion coefficient were modeled to quantitatively calculate the effect of thermal expansion and contraction on the dimensions of specimen and punch. The theoretical analysis results indicate that depth reduction and opening expansion are produced by cryogenic springback, determined by the radial stress, hoop stress, and bending moment in different deformation regions. The cryogenic springback in the biaxial tensile stress zone was reduced by 37.8 % owing to the increasing radial deformation and decreasing bending deformation. In contrast, cryogenic springback in the tensile-compressive stress zone increased by 30.8 %. The punch cooling shrinkage and specimen warming expansion in depth direction can reduce for the dimensional deviation caused by springback but cause the opposite effect in hoop direction. Expansion and shrinkage were effectively predicted using the proposed model, with an error of less than 16 %. The deformation region of the biaxial tensile stress can be enlarged by the significantly improved hardening ability at cryogenic temperature, which benefits enhancing deformation uniformity and further reduces springback. Therefore, cryogenic forming offers considerable potential for the precision manufacturing of aluminum alloy deep-cavity thin-walled components.
{"title":"Dimensional change and springback of spherical shell in cryogenic forming","authors":"Fangxing Wu , Xiaobo Fan , Guang Yang , Xianshuo Chen , Shijian Yuan","doi":"10.1016/j.ijmecsci.2024.109757","DOIUrl":"10.1016/j.ijmecsci.2024.109757","url":null,"abstract":"<div><div>Cryogenic forming has been developed to manufacture thin-walled curved aluminum alloy components, whose final dimensions are affected by cryogenic shrinkage and springback. Therefore, dimensional changes of spherical shell in cryogenic forming were studied theoretically and experimentally. The cryogenic forming process was discussed to elucidate the factors affecting the dimensional change. The stress distribution was analyzed to qualitatively reveal the springback behavior. Cryogenic dimensional measurement devices were built to quantitatively evaluate the dimensional changes in the forming processes of punch cooling, springback, and specimen restoration to room temperature. The temperature dependencies of the elastic modulus and expansion coefficient were modeled to quantitatively calculate the effect of thermal expansion and contraction on the dimensions of specimen and punch. The theoretical analysis results indicate that depth reduction and opening expansion are produced by cryogenic springback, determined by the radial stress, hoop stress, and bending moment in different deformation regions. The cryogenic springback in the biaxial tensile stress zone was reduced by 37.8 % owing to the increasing radial deformation and decreasing bending deformation. In contrast, cryogenic springback in the tensile-compressive stress zone increased by 30.8 %. The punch cooling shrinkage and specimen warming expansion in depth direction can reduce for the dimensional deviation caused by springback but cause the opposite effect in hoop direction. Expansion and shrinkage were effectively predicted using the proposed model, with an error of less than 16 %. The deformation region of the biaxial tensile stress can be enlarged by the significantly improved hardening ability at cryogenic temperature, which benefits enhancing deformation uniformity and further reduces springback. Therefore, cryogenic forming offers considerable potential for the precision manufacturing of aluminum alloy deep-cavity thin-walled components.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109757"},"PeriodicalIF":7.1,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.ijmecsci.2024.109768
Richard Rodriguez-Feliciano, K.W. Wang
Multistable origami structures have been exploited for mechanical property tailoring, deployable robotic arms, wave propagation tuning and others, due to its ability to possess multiple stable states with distinct properties. Traditionally these structures are made by assembling bistable unit cells, which results in a significant increase in the size and weight of the system when larger number of stable states are required. Recently, researchers have uncovered a third stable state in the Kresling origami pattern. Although this is an advancement over the bistable unit cell, there is an unexplored opportunity for more systematically expanding the design space of Kresling unit cells to possess many more stable configurations (>>2) and enhance its programmable multistability. In this research, we seek to develop a methodology for the design of a Kresling origami-inspired unit cell that can be easily programmed to achieve up to 10 stable configurations, with the potential to achieve even more. We exploit the rich kinematics of the Kresling origami-inspired unit cell, that arise from its coupled translational and rotational deployment, and propose the strategic integration of tensile elements to realize multiple stable states. Analytically, we study the unstretched length values (defined to be the precise length between the string “slacked” and “tensioned” configurations) of the strings that yield the distinct number of stable states. We present the potential energy profiles with its corresponding force-displacement plots for the bistable, tristable, quadstable, pentastable and decastable unit cells. Moreover, we show that by simply adjusting the unstretched length of the strings we can program and tune the number of stable states of the unit cell. Tristable and pentastable unit cell prototypes are designed and experimentally tested to validate the proposed methodology. Lastly, a study is performed on the mechanical property tailoring capabilities of two unit cells assembled in series. The results show that the decastable unit cell assembly can achieve up to 55 discrete values of equivalent stiffness, while the bistable one can only achieve 3. For the bistable unit cell assembly to match this number, it will require 54 unit cells in series, which will significantly increase the size and weight of the structural system. These findings show that the modular structure will have more programmable capabilities, while maintaining its size and weight at a minimum, as the number of stable states per unit cell is increased.
{"title":"Synthesis of a highly programmable multistable Kresling origami-inspired unit cell","authors":"Richard Rodriguez-Feliciano, K.W. Wang","doi":"10.1016/j.ijmecsci.2024.109768","DOIUrl":"10.1016/j.ijmecsci.2024.109768","url":null,"abstract":"<div><div>Multistable origami structures have been exploited for mechanical property tailoring, deployable robotic arms, wave propagation tuning and others, due to its ability to possess multiple stable states with distinct properties. Traditionally these structures are made by assembling bistable unit cells, which results in a significant increase in the size and weight of the system when larger number of stable states are required. Recently, researchers have uncovered a third stable state in the Kresling origami pattern. Although this is an advancement over the bistable unit cell, there is an unexplored opportunity for more systematically expanding the design space of Kresling unit cells to possess many more stable configurations (>>2) and enhance its programmable multistability. In this research, we seek to develop a methodology for the design of a Kresling origami-inspired unit cell that can be easily programmed to achieve up to 10 stable configurations, with the potential to achieve even more. We exploit the rich kinematics of the Kresling origami-inspired unit cell, that arise from its coupled translational and rotational deployment, and propose the strategic integration of tensile elements to realize multiple stable states. Analytically, we study the unstretched length values (defined to be the precise length between the string “slacked” and “tensioned” configurations) of the strings that yield the distinct number of stable states. We present the potential energy profiles with its corresponding force-displacement plots for the bistable, tristable, quadstable, pentastable and decastable unit cells. Moreover, we show that by simply adjusting the unstretched length of the strings we can program and tune the number of stable states of the unit cell. Tristable and pentastable unit cell prototypes are designed and experimentally tested to validate the proposed methodology. Lastly, a study is performed on the mechanical property tailoring capabilities of two unit cells assembled in series. The results show that the decastable unit cell assembly can achieve up to 55 discrete values of equivalent stiffness, while the bistable one can only achieve 3. For the bistable unit cell assembly to match this number, it will require 54 unit cells in series, which will significantly increase the size and weight of the structural system. These findings show that the modular structure will have more programmable capabilities, while maintaining its size and weight at a minimum, as the number of stable states per unit cell is increased.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109768"},"PeriodicalIF":7.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.ijmecsci.2024.109766
Ruihua Liang , Weifeng Liu , Yuguang Fu , Meng Ma
Physics-informed deep learning has emerged as a promising approach that incorporates physical constraints into the model, reduces the amount of data required, and demonstrates robustness and potential in dealing with limited datasets for a variety of studies. However, several key challenges still exist, with one being the spectral bias problem of deep learning in the simulation of functions with multi-frequency features. To overcome the challenge, this study proposes a novel physics-informed deep learning method, which integrates physics-informed neural network with Fourier transform so as to solve partial differential equations in the frequency domain, thus alleviating the problem of spectral bias of neural networks in the simulation of multi-frequency functions. In addition, the proposed method is used to focus on the forward simulation and parameter inverse identification issues in structural dynamics under moving loads. To illustrate the superiority of the method, the issues of dynamic response of simply supported beams under moving loads are presented as case studies, and the performance of the method in multiple cases is analysed and discussed. The research results demonstrate the feasibility and effectiveness of the method for structural dynamics simulation and parameter inverse identifications using limited datasets.
{"title":"Physics-informed deep learning for structural dynamics under moving load","authors":"Ruihua Liang , Weifeng Liu , Yuguang Fu , Meng Ma","doi":"10.1016/j.ijmecsci.2024.109766","DOIUrl":"10.1016/j.ijmecsci.2024.109766","url":null,"abstract":"<div><div>Physics-informed deep learning has emerged as a promising approach that incorporates physical constraints into the model, reduces the amount of data required, and demonstrates robustness and potential in dealing with limited datasets for a variety of studies. However, several key challenges still exist, with one being the spectral bias problem of deep learning in the simulation of functions with multi-frequency features. To overcome the challenge, this study proposes a novel physics-informed deep learning method, which integrates physics-informed neural network with Fourier transform so as to solve partial differential equations in the frequency domain, thus alleviating the problem of spectral bias of neural networks in the simulation of multi-frequency functions. In addition, the proposed method is used to focus on the forward simulation and parameter inverse identification issues in structural dynamics under moving loads. To illustrate the superiority of the method, the issues of dynamic response of simply supported beams under moving loads are presented as case studies, and the performance of the method in multiple cases is analysed and discussed. The research results demonstrate the feasibility and effectiveness of the method for structural dynamics simulation and parameter inverse identifications using limited datasets.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109766"},"PeriodicalIF":7.1,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ijmecsci.2024.109765
Lusheng Yuan, Liang Wang, Rui Qi, Yan Li, Chuangye Liu, Gang Luo
To address the challenge of achieving extensive travel and high precision in semiconductor inspection, this study proposes a novel 2-DOF cross-scale piezoelectric positioning platform. In semiconductor inspection, the platform utilizes elliptical, stick-slip, and direct-push drive modes to meet the motion requirements at millimeter, micrometer, and nanometer scales. By applying defined electrical signals to the piezoelectric units, the platform can achieve high-speed continuous mode (HCM) for the millimeter scale, low-speed stepping mode (LSM) for the micrometer scale, and high-precision positioning mode (HPM) for the nanometer scale. Theoretical analysis and simulations were performed to design the flexible stator of the platform, and its dynamic characteristics were analyzed. A prototype was fabricated, assembled, and experimentally tested to investigate the mechanical performance of the proposed platform. The results show that the prototype successfully realizes cross-scale motion in the three modes: achieving a maximum no-load speed of 62.47 mm/s in HCM, a low-speed stepping motion of 14.62 μm/s in LSM, and high-precision positioning with a resolution of 25 nm within a range of ±21 μm in HPM. Through the flexible switching and cooperation of the three drive modes, the platform can quickly approach the target at millimeter speed, further approach with micrometer step motion, and finally achieve nanometer precision positioning. Finally, the positioning platform was successfully applied to inspect semiconductor devices for defect inspection. This study explores a novel cross-scale driving method for piezoelectric positioning platforms, which provides a new approach for precision manipulation research related to semiconductor component inspection.
{"title":"A 2-DOF piezoelectric platform for cross-scale semiconductor inspection","authors":"Lusheng Yuan, Liang Wang, Rui Qi, Yan Li, Chuangye Liu, Gang Luo","doi":"10.1016/j.ijmecsci.2024.109765","DOIUrl":"10.1016/j.ijmecsci.2024.109765","url":null,"abstract":"<div><div>To address the challenge of achieving extensive travel and high precision in semiconductor inspection, this study proposes a novel 2-DOF cross-scale piezoelectric positioning platform. In semiconductor inspection, the platform utilizes elliptical, stick-slip, and direct-push drive modes to meet the motion requirements at millimeter, micrometer, and nanometer scales. By applying defined electrical signals to the piezoelectric units, the platform can achieve high-speed continuous mode (HCM) for the millimeter scale, low-speed stepping mode (LSM) for the micrometer scale, and high-precision positioning mode (HPM) for the nanometer scale. Theoretical analysis and simulations were performed to design the flexible stator of the platform, and its dynamic characteristics were analyzed. A prototype was fabricated, assembled, and experimentally tested to investigate the mechanical performance of the proposed platform. The results show that the prototype successfully realizes cross-scale motion in the three modes: achieving a maximum no-load speed of 62.47 mm/s in HCM, a low-speed stepping motion of 14.62 μm/s in LSM, and high-precision positioning with a resolution of 25 nm within a range of ±21 μm in HPM. Through the flexible switching and cooperation of the three drive modes, the platform can quickly approach the target at millimeter speed, further approach with micrometer step motion, and finally achieve nanometer precision positioning. Finally, the positioning platform was successfully applied to inspect semiconductor devices for defect inspection. This study explores a novel cross-scale driving method for piezoelectric positioning platforms, which provides a new approach for precision manipulation research related to semiconductor component inspection.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109765"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ijmecsci.2024.109763
E. Pantaleoni , E. Riva , A. Erturk
The dynamics of topological boundary modes in both periodic and quasi-periodic electromechanical metastructures is investigated, with a focus on their applications to energy harvesting and vibration reduction. The metastructure analyzed in this study is based on a shunted array of piezoelectric patches, with electrical parameters modulated according to the 1D Aubry–André–Harper model. As a result of this modulation, a fractal spectrum is generated near the central frequency of the resonators, a hallmark of nontrivial topology that enables the emergence of digitally controllable edge states and ensuing localization phenomena at subwavelength frequencies. In this framework, a detailed analysis of the metastructure spectral characteristics is conducted to investigate the influence of the modulation parameters on mode localization, both at the boundaries and within the interior of the beam. Such localization effects are then studied in relation to the energy harvesting, attenuation, and wave transport capabilities of the system. These functionalities point toward the realization of self-powered structures with low frequency and digitally controllable vibration attenuation capabilities, and are considered of significant technological interest in applications involving elastic waves and vibrations, where the ability to precisely control and harness these phenomena could lead to innovative solutions in energy-efficient and adaptive systems.
{"title":"Topological modes, vibration attenuation, and energy harvesting in electromechanical metastructures","authors":"E. Pantaleoni , E. Riva , A. Erturk","doi":"10.1016/j.ijmecsci.2024.109763","DOIUrl":"10.1016/j.ijmecsci.2024.109763","url":null,"abstract":"<div><div>The dynamics of topological boundary modes in both periodic and quasi-periodic electromechanical metastructures is investigated, with a focus on their applications to energy harvesting and vibration reduction. The metastructure analyzed in this study is based on a shunted array of piezoelectric patches, with electrical parameters modulated according to the 1D Aubry–André–Harper model. As a result of this modulation, a fractal spectrum is generated near the central frequency of the resonators, a hallmark of nontrivial topology that enables the emergence of digitally controllable edge states and ensuing localization phenomena at subwavelength frequencies. In this framework, a detailed analysis of the metastructure spectral characteristics is conducted to investigate the influence of the modulation parameters on mode localization, both at the boundaries and within the interior of the beam. Such localization effects are then studied in relation to the energy harvesting, attenuation, and wave transport capabilities of the system. These functionalities point toward the realization of self-powered structures with low frequency and digitally controllable vibration attenuation capabilities, and are considered of significant technological interest in applications involving elastic waves and vibrations, where the ability to precisely control and harness these phenomena could lead to innovative solutions in energy-efficient and adaptive systems.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109763"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ijmecsci.2024.109764
Jiangqin Ge , Yuheng Lin , Huan Qi , Yuntang Li , Xiaolu Li , Chen Li , Zhian Li , Kengqing Xu
In the abrasive jet polishing (AJP) process, applying ultrasonic vibration to the jet beam can effectively improve the cutting kinetic energy of the abrasive particles, but it simultaneously causes significant variations in the jet morphology. However, less research has been done on the relationship between the jet morphology and the polishing efficiency. This paper established a fluid mechanic model to study the effect of jet morphology evolution on the polishing efficiency. The accuracy of the computational results was verified from multiple perspectives through the high-speed camera capture, the targeted erosion experiments and the polishing experiments. It was found that there exists an effective target distance for each amplitude, beyond which ultrasonic vibration cannot improve the polishing efficiency. The effective target distance can be expanded by reducing the amplitude or increasing the frequency. The research findings reveal the evolution process of the pulse morphology induced by the ultrasonic vibration and the variation pattern of pulse dynamic pressure with respect to the target distance, which can provide a theoretical basis for designing the vibration parameters in the AJP process enhanced by the ultrasonic vibration.
{"title":"The impact of ultrasonic-induced jet morphology on polishing efficiency","authors":"Jiangqin Ge , Yuheng Lin , Huan Qi , Yuntang Li , Xiaolu Li , Chen Li , Zhian Li , Kengqing Xu","doi":"10.1016/j.ijmecsci.2024.109764","DOIUrl":"10.1016/j.ijmecsci.2024.109764","url":null,"abstract":"<div><div>In the abrasive jet polishing (AJP) process, applying ultrasonic vibration to the jet beam can effectively improve the cutting kinetic energy of the abrasive particles, but it simultaneously causes significant variations in the jet morphology. However, less research has been done on the relationship between the jet morphology and the polishing efficiency. This paper established a fluid mechanic model to study the effect of jet morphology evolution on the polishing efficiency. The accuracy of the computational results was verified from multiple perspectives through the high-speed camera capture, the targeted erosion experiments and the polishing experiments. It was found that there exists an effective target distance for each amplitude, beyond which ultrasonic vibration cannot improve the polishing efficiency. The effective target distance can be expanded by reducing the amplitude or increasing the frequency. The research findings reveal the evolution process of the pulse morphology induced by the ultrasonic vibration and the variation pattern of pulse dynamic pressure with respect to the target distance, which can provide a theoretical basis for designing the vibration parameters in the AJP process enhanced by the ultrasonic vibration.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109764"},"PeriodicalIF":7.1,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.ijmecsci.2024.109759
Xuan Yang , Biao Li , Yazhi Li , Baishun Yang , Kun Zhou
The multi-physics coupling feature of the laser powder bed fusion (LPBF) process poses great challenges to numerical models regarding computational fidelity and efficiency. This paper proposed a finite volume–based model for predicting integrated thermo-fluid-mechanical behaviors of the LPBF process. The model directly unifies the heat transfer, fluid flow and solid mechanics simulations within a predefined mesh, enabling simultaneous solutions for the fluid domain under Eulerian description and the solid domain under Lagrangian description. Three benchmark tests accounting for individual problems were conducted to validate the model's accuracy and effectiveness. Track-scale LPBF simulations were performed to unravel the intricate interplay between thermal, fluid and mechanical behaviors. The numerical predictions of surface morphologies, molten pool dynamics and melt track dimensions aligned well with the experimental observations. The spatiotemporal evolution of transient thermal stress was accurately captured and the predicted residual stress field showed consistency with nanoindentation measurements. The proposed model was found robust in simultaneously predicting the temperature distribution, melt flow and residual stress evolutions of the LPBF process, and showed strong potential for addressing other similar multi-physics coupling problems.
{"title":"A finite volume–based thermo-fluid-mechanical model of the LPBF process","authors":"Xuan Yang , Biao Li , Yazhi Li , Baishun Yang , Kun Zhou","doi":"10.1016/j.ijmecsci.2024.109759","DOIUrl":"10.1016/j.ijmecsci.2024.109759","url":null,"abstract":"<div><div>The multi-physics coupling feature of the laser powder bed fusion (LPBF) process poses great challenges to numerical models regarding computational fidelity and efficiency. This paper proposed a finite volume–based model for predicting integrated thermo-fluid-mechanical behaviors of the LPBF process. The model directly unifies the heat transfer, fluid flow and solid mechanics simulations within a predefined mesh, enabling simultaneous solutions for the fluid domain under Eulerian description and the solid domain under Lagrangian description. Three benchmark tests accounting for individual problems were conducted to validate the model's accuracy and effectiveness. Track-scale LPBF simulations were performed to unravel the intricate interplay between thermal, fluid and mechanical behaviors. The numerical predictions of surface morphologies, molten pool dynamics and melt track dimensions aligned well with the experimental observations. The spatiotemporal evolution of transient thermal stress was accurately captured and the predicted residual stress field showed consistency with nanoindentation measurements. The proposed model was found robust in simultaneously predicting the temperature distribution, melt flow and residual stress evolutions of the LPBF process, and showed strong potential for addressing other similar multi-physics coupling problems.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"284 ","pages":"Article 109759"},"PeriodicalIF":7.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.ijmecsci.2024.109756
Zuowei Wang, Shilong Wang, Tianpeng An, Tuanjie Li
Developing piezoelectric-based plate-like metamaterials necessitates an effective modeling method to elucidate the omnidirectional wave properties of piezoelectric coupled inclusions on a thin plate. The commonly used methods, such as the transfer-matrix method and finite element method, are inadequate for analyzing the transmission and reflection of omnidirectional waves in a two-dimensional elastic medium. Unlike the existing methods, the multiple scattering method employs Bessel functions as the displacement-basis methods which can accurately describe the propagation and scattering characteristics of omnidirectional waves. This paper develops a novel T-matrix formulation to support the multiple scattering method, representing the input-output relationship between incident and reflected waves from a piezoelectric shunt inclusion on a host thin plate. The piezoelectric shunt inclusion comprises a varying-thickness substrate bonded with piezoelectric shunting patches. The T-matrix of the piezoelectric shunt inclusion is formulated by integrating the wave-based method with Rayleigh-Ritz method. The derived T-matrix is then used to semi-analytically analyze the far-field scattering and reflection properties of a single inclusion. Numerical results capture the scattering properties resulting from trapped mode resonances of the piezoelectric shunt inclusion. Additionally, the capability of the piezoelectric shunt damping to design and tune multiple critical coupling conditions for axisymmetric modes of thin plates is parametrically investigated by varying the values of inductors and resistors.
开发基于压电的板状超材料需要一种有效的建模方法来阐明薄板上压电耦合夹杂物的全向波特性。常用的方法，如传递矩阵法和有限元法，都不足以分析全向波在二维弹性介质中的传输和反射。与现有方法不同，多重散射法采用贝塞尔函数作为位移基础方法，能准确描述全向波的传播和散射特性。本文开发了一种新颖的 T 矩阵公式来支持多重散射法，表示主机薄板上的压电分流包络体的入射波和反射波之间的输入输出关系。压电分流器包含一个厚度不等的基板，基板上粘接有压电分流器贴片。通过将基于波的方法与雷利-里兹方法进行整合，可以计算出压电分流包络的 T 矩阵。然后利用推导出的 T 矩阵对单个包体的远场散射和反射特性进行半分析。数值结果捕捉到了压电分流包体的陷模共振所产生的散射特性。此外，通过改变电感器和电阻器的值，对压电分流阻尼设计和调整薄板轴对称模式的多个临界耦合条件的能力进行了参数化研究。
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