Wang YuanLiang, Liao YanQing, Peng Jiahui, N. yongzhong, Hong Xu
This paper is concerned with the two simple numerical implementation methods for a damage-coupled Chaboche-type viscoplastic constitutive model. By considering the damage variable as a constant in each incremental step, the return-mapping procedure is reduced to the solution of only one nonlinear scalar equation. Depending on the use of damage value in the current or prior incremental state, the two methods are named the backward difference implicit integration scheme and the two-step explicit integration scheme respectively. These two numerical algorithms are implemented into the ANSYS software by developing the USERMAT subroutine and verified by comparing them with available experimental data. Several numerical examples on the Gauss point level are studied in terms of stability, accuracy, computational efficiency, and applicability for further numerical observation. In addition to higher computational efficiency and lower memory requirements, the two methods can be easily extended to other damage models due to their simplicity.
{"title":"Two simple numerical implementation methods for damage coupled viscoplastic constitutive model","authors":"Wang YuanLiang, Liao YanQing, Peng Jiahui, N. yongzhong, Hong Xu","doi":"10.1115/1.4062534","DOIUrl":"https://doi.org/10.1115/1.4062534","url":null,"abstract":"\u0000 This paper is concerned with the two simple numerical implementation methods for a damage-coupled Chaboche-type viscoplastic constitutive model. By considering the damage variable as a constant in each incremental step, the return-mapping procedure is reduced to the solution of only one nonlinear scalar equation. Depending on the use of damage value in the current or prior incremental state, the two methods are named the backward difference implicit integration scheme and the two-step explicit integration scheme respectively. These two numerical algorithms are implemented into the ANSYS software by developing the USERMAT subroutine and verified by comparing them with available experimental data. Several numerical examples on the Gauss point level are studied in terms of stability, accuracy, computational efficiency, and applicability for further numerical observation. In addition to higher computational efficiency and lower memory requirements, the two methods can be easily extended to other damage models due to their simplicity.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42941050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quasi-static peeling of a finite-length, flexible, horizontal, one-dimensional (1-D) plate (strip, thin film) from a horizontal, thin, elastomeric layer (foundation) is considered. The displaced end of the plate is subjected to an upward deflection or to a rotation. The top of the interlayer is perfectly bonded to the plate, and its lower surface is bonded to a rigid, flat substrate. A transversality (debonding) condition is derived for peeling, based on the common fracture mechanics approach. Whereas debonding from a Winkler foundation can be expressed in terms of the displacement (or equivalently the foundation stress ) at the bond termination, the sixth-order formulation involves a more complex debonding criterion. Transversality relationships are used to describe this limit state (here the onset of debonding) in terms of co-state variables, herein the deflection and slope at the peel front. In the analysis, bending is assumed to be paramount, linear Kirchhoff-Love (classical) plate theory is used to model the deformation, and therefore displacements are assumed to be small. The foundation is linearly elastic and incompressible. The effects of the work of adhesion, the length of the plate, and the initial nonbonded length of the plate are investigated. The results are compared to those for a Winkler foundation. By replacing the shear modulus of the interlayer by viscosity, and displacements by their time derivatives, the results are expected to apply to viscous liquid interlayers as well.
{"title":"Peeling of Finite-Length Plates From an Elastomeric Foundation: A 1-D Cylindrical Bending Solution","authors":"R. Plaut, D. Dillard","doi":"10.1115/1.4062493","DOIUrl":"https://doi.org/10.1115/1.4062493","url":null,"abstract":"Quasi-static peeling of a finite-length, flexible, horizontal, one-dimensional (1-D) plate (strip, thin film) from a horizontal, thin, elastomeric layer (foundation) is considered. The displaced end of the plate is subjected to an upward deflection or to a rotation. The top of the interlayer is perfectly bonded to the plate, and its lower surface is bonded to a rigid, flat substrate. A transversality (debonding) condition is derived for peeling, based on the common fracture mechanics approach. Whereas debonding from a Winkler foundation can be expressed in terms of the displacement (or equivalently the foundation stress ) at the bond termination, the sixth-order formulation involves a more complex debonding criterion. Transversality relationships are used to describe this limit state (here the onset of debonding) in terms of co-state variables, herein the deflection and slope at the peel front. In the analysis, bending is assumed to be paramount, linear Kirchhoff-Love (classical) plate theory is used to model the deformation, and therefore displacements are assumed to be small. The foundation is linearly elastic and incompressible. The effects of the work of adhesion, the length of the plate, and the initial nonbonded length of the plate are investigated. The results are compared to those for a Winkler foundation. By replacing the shear modulus of the interlayer by viscosity, and displacements by their time derivatives, the results are expected to apply to viscous liquid interlayers as well.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44275244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nonlinear phononic materials enable superior wave responses by combining nonlinearity with their inherent periodicity, creating opportunities for the development of novel acoustic devices. However, the field has largely focused on reversible nonlinearities, whereas the role of hysteretic nonlinearity remains unexplored. In this work, we investigate nonlinear shear wave responses arising from the hysteretic nonlinearity of frictional rough contacts, and harness these responses to enable programmable functions. Using a numerical approach, we solve the strongly nonlinear problem of shear wave propagation through a single contact and a periodic array of contacts, accounting for frictional effects. Specifically, the Jenkin friction model with experimentally-obtained properties is used to capture the effects of stick-slip transition at the contacts. Results show that friction gives rise to shear-polarized eigenstrains, which are residual static deformations within the system. We then demonstrate how eigenstrain generation in multiple contacts can enable programmable functionalities such as an acoustically-controlled mechanical switch, precision position control, and surface reconfigurability. Overall, our findings open new avenues for designing smart materials and devices with advanced functionalities via acoustic waves using the hysteretic nonlinearity of frictional contacts.
{"title":"Shear Wave-induced Friction at Periodic Interfaces for Programmable Mechanical Responses","authors":"Ganesh U. Patil, A. Fantetti, K. Matlack","doi":"10.1115/1.4062494","DOIUrl":"https://doi.org/10.1115/1.4062494","url":null,"abstract":"\u0000 Nonlinear phononic materials enable superior wave responses by combining nonlinearity with their inherent periodicity, creating opportunities for the development of novel acoustic devices. However, the field has largely focused on reversible nonlinearities, whereas the role of hysteretic nonlinearity remains unexplored. In this work, we investigate nonlinear shear wave responses arising from the hysteretic nonlinearity of frictional rough contacts, and harness these responses to enable programmable functions. Using a numerical approach, we solve the strongly nonlinear problem of shear wave propagation through a single contact and a periodic array of contacts, accounting for frictional effects. Specifically, the Jenkin friction model with experimentally-obtained properties is used to capture the effects of stick-slip transition at the contacts. Results show that friction gives rise to shear-polarized eigenstrains, which are residual static deformations within the system. We then demonstrate how eigenstrain generation in multiple contacts can enable programmable functionalities such as an acoustically-controlled mechanical switch, precision position control, and surface reconfigurability. Overall, our findings open new avenues for designing smart materials and devices with advanced functionalities via acoustic waves using the hysteretic nonlinearity of frictional contacts.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45927083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft bioinspired fiber networks offer great potential in biomedical engineering and material design due to their adjustable mechanical behaviors. However, existing strategies to integrate modeling and manufacturing of bioinspired networks do not consider the intrinsic microstructural disorder of biopolymer networks, which limits the ability to tune their mechanical properties. To fill in this gap, we developed a method to generate computer models of aperiodic fiber networks mimicking type I collagen ready to be submitted for additive manufacturing. The models of fiber networks were created in a scripting language wherein key geometric features like connectivity, fiber length, and fiber cross section could be easily tuned to achieve desired mechanical behavior, namely pretension induced shear stiffening. The stiffening was first predicted using finite element software, and then a representative network was fabricated using a commercial 3D printer based on digital light processing technology using a soft resin. The stiffening response of the fabricated network was verified experimentally on a novel test device capable of testing the shear modulus of the specimen under varying levels of uniaxial pretension. The resulting data demonstrated clear pretension-induced stiffening in shear in the fabricated network, with uniaxial pretension of 40% resulting in a factor of 2.65 increase in the small strain shear modulus. The strategy described in this manuscript addresses the challenges in modeling bioinspired fiber networks and can be readily integrated with the advances in fabrication technology to fabricate materials truly replicating the mechanical response of biopolymer networks.
{"title":"Bioinspired Fiber Networks with Tunable Mechanical Properties by Additive Manufacturing","authors":"M. Sarkar, J. Notbohm","doi":"10.1115/1.4062451","DOIUrl":"https://doi.org/10.1115/1.4062451","url":null,"abstract":"\u0000 Soft bioinspired fiber networks offer great potential in biomedical engineering and material design due to their adjustable mechanical behaviors. However, existing strategies to integrate modeling and manufacturing of bioinspired networks do not consider the intrinsic microstructural disorder of biopolymer networks, which limits the ability to tune their mechanical properties. To fill in this gap, we developed a method to generate computer models of aperiodic fiber networks mimicking type I collagen ready to be submitted for additive manufacturing. The models of fiber networks were created in a scripting language wherein key geometric features like connectivity, fiber length, and fiber cross section could be easily tuned to achieve desired mechanical behavior, namely pretension induced shear stiffening. The stiffening was first predicted using finite element software, and then a representative network was fabricated using a commercial 3D printer based on digital light processing technology using a soft resin. The stiffening response of the fabricated network was verified experimentally on a novel test device capable of testing the shear modulus of the specimen under varying levels of uniaxial pretension. The resulting data demonstrated clear pretension-induced stiffening in shear in the fabricated network, with uniaxial pretension of 40% resulting in a factor of 2.65 increase in the small strain shear modulus. The strategy described in this manuscript addresses the challenges in modeling bioinspired fiber networks and can be readily integrated with the advances in fabrication technology to fabricate materials truly replicating the mechanical response of biopolymer networks.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49372329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accurate prediction of the force required to puncture a soft material is critical in many fields like medical technology, food processing, and manufacturing. However, such a prediction strongly depends on our understanding of the complex nonlinear behavior of the material subject to deep indentation and complex failure mechanisms. Only recently we developed theories capable of correlating puncture force with material properties and needle geometry. However, such models are based on simplifications that seldom limit their applicability to real cases. One common assumption is the incompressibility of the cut material, albeit no material is truly incompressible. In this paper we propose a simple model that accounts for linearly elastic compressibility, and its interplay with toughness, stiffness, and elastic strain-stiffening. Confirming previous theories and experiments, materials having high-toughness and low-modulus exhibit the highest puncture resistance at a given needle radius. Surprisingly, in these conditions, we observe that incompressible materials exhibit the lowest puncture resistance, where volumetric compressibility can create an additional (strain) energy barrier to puncture. Our model provides a valuable tool to assess the puncture resistance of soft compressible materials and suggests new design strategies for sharp needles and puncture-resistant materials.
{"title":"Theoretical Puncture Mechanics of Soft Compressible Solids","authors":"Stefano Fregonese, Z. Tong, Si-Yao Wang, M. Bacca","doi":"10.1115/1.4062844","DOIUrl":"https://doi.org/10.1115/1.4062844","url":null,"abstract":"\u0000 Accurate prediction of the force required to puncture a soft material is critical in many fields like medical technology, food processing, and manufacturing. However, such a prediction strongly depends on our understanding of the complex nonlinear behavior of the material subject to deep indentation and complex failure mechanisms. Only recently we developed theories capable of correlating puncture force with material properties and needle geometry. However, such models are based on simplifications that seldom limit their applicability to real cases. One common assumption is the incompressibility of the cut material, albeit no material is truly incompressible. In this paper we propose a simple model that accounts for linearly elastic compressibility, and its interplay with toughness, stiffness, and elastic strain-stiffening. Confirming previous theories and experiments, materials having high-toughness and low-modulus exhibit the highest puncture resistance at a given needle radius. Surprisingly, in these conditions, we observe that incompressible materials exhibit the lowest puncture resistance, where volumetric compressibility can create an additional (strain) energy barrier to puncture. Our model provides a valuable tool to assess the puncture resistance of soft compressible materials and suggests new design strategies for sharp needles and puncture-resistant materials.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48975309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Pahari, Eugenia Stanisauskis, S. Mashayekhi, W. Oates
Entropy dynamics is a Bayesian inference methodology that can be used to quantify time-dependent posterior probability densities that guide development of complex material models using information theory. Here we expand its application to non-Gaussian processes to evaluate how fractal structure can influence fractional hyperelasticity and viscoelasticity in elastomers. We investigate how kinematic constraints on fractal polymer network deformation influences the form of hyperelastic constitutive behavior and viscoelasticity in soft materials such as dielectric elastomers which have applications in the development of adaptive structures. The modeling framework is validated on two dielectric elastomers, VHB 4910 and 4949, over a broad range of stretch rates. It is shown that local fractal time derivatives are equally effective at predicting viscoelasticity in these materials in comparison to non-local fractional time derivatives under constant stretch rates. We describe the origin of this accuracy which has implications for simulating larger scale problems such as finite element analysis given the differences in computational efficiency of non-local fractional derivatives versus local fractal derivatives.
{"title":"An Entropy Dynamics Approach for Deriving and Applying Fractal and Fractional Order Viscoelasticity to Elastomers","authors":"B. Pahari, Eugenia Stanisauskis, S. Mashayekhi, W. Oates","doi":"10.1115/1.4062389","DOIUrl":"https://doi.org/10.1115/1.4062389","url":null,"abstract":"\u0000 Entropy dynamics is a Bayesian inference methodology that can be used to quantify time-dependent posterior probability densities that guide development of complex material models using information theory. Here we expand its application to non-Gaussian processes to evaluate how fractal structure can influence fractional hyperelasticity and viscoelasticity in elastomers. We investigate how kinematic constraints on fractal polymer network deformation influences the form of hyperelastic constitutive behavior and viscoelasticity in soft materials such as dielectric elastomers which have applications in the development of adaptive structures. The modeling framework is validated on two dielectric elastomers, VHB 4910 and 4949, over a broad range of stretch rates. It is shown that local fractal time derivatives are equally effective at predicting viscoelasticity in these materials in comparison to non-local fractional time derivatives under constant stretch rates. We describe the origin of this accuracy which has implications for simulating larger scale problems such as finite element analysis given the differences in computational efficiency of non-local fractional derivatives versus local fractal derivatives.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42464551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoling Jin, Zhanchao Huang, Yong Wang, Zhilong Huang, I. Elishakoff
Canonical equations play a pivotal role in many sub-fields of physics and mathematics. For complex systems and systems without first principles, however, deriving canonical equations analytically is quite laborious or might even be impossible. This work is devoted to automatedly distilling the canonical equations only from random state data. The random state data are collected from stochastically excited, dissipative dynamical systems, experimentally or numerically, while other information, such as the system characterization itself and the excitations are not needed. The identification procedure comes down to a nested optimization problem, and the explicit expressions of the momentum (density) functions and energy (density) functions are identified simultaneously. Three representative examples are investigated to illustrate its high accuracy of identification, the small requirement on data amount, and high robustness to excitations and dissipation. The identification procedure servers as a filter, filtering out the non-conservative information while retaining the conservative information, which is especially suitable for systems with excitations not obtainable.
{"title":"Automatedly Distilling Canonical Equations from Random State Data","authors":"Xiaoling Jin, Zhanchao Huang, Yong Wang, Zhilong Huang, I. Elishakoff","doi":"10.1115/1.4062329","DOIUrl":"https://doi.org/10.1115/1.4062329","url":null,"abstract":"Canonical equations play a pivotal role in many sub-fields of physics and mathematics. For complex systems and systems without first principles, however, deriving canonical equations analytically is quite laborious or might even be impossible. This work is devoted to automatedly distilling the canonical equations only from random state data. The random state data are collected from stochastically excited, dissipative dynamical systems, experimentally or numerically, while other information, such as the system characterization itself and the excitations are not needed. The identification procedure comes down to a nested optimization problem, and the explicit expressions of the momentum (density) functions and energy (density) functions are identified simultaneously. Three representative examples are investigated to illustrate its high accuracy of identification, the small requirement on data amount, and high robustness to excitations and dissipation. The identification procedure servers as a filter, filtering out the non-conservative information while retaining the conservative information, which is especially suitable for systems with excitations not obtainable.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45787449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The analysis and design of materials is often a slow process that may take weeks, months, or years. And, many current material platforms rely on expensive raw material sources and fail to achieve sustainability goals. Meanwhile, bio-inspired Materials Informatics – fueled by emerging techniques such as multiscale modeling, machine learning and autonomous experimentation – is transforming the way materials are understood, discovered, developed, and selected. The impact of these tools is particularly noteworthy since they can be used to develop materials with fewer resources and with greater societal impact. A field that would strongly benefit from the use of Materials Informatics tools is that of structural biological materials, where mechanical properties are crucial for biological and engineering properties for species survival such as fracture resistant armor against predators, elastic recovery for repeated loadings, or mechanical actuation capacity. Generations of researchers have studied biological materials for their fascinating structure-property relationships that make up their impressive properties, including mechanical resilience. Despite the accumulation of scientific knowledge, relatively little has been translated to generating engineered bio-inspired materials. Addressing this gap, emerging Materials Informatics tools can now be used to make use of legacy data, newly collected empirical observations, and predictive models to make significant advances in this field.
{"title":"Materials Informatics tools in the context of bio-inspired material mechanics","authors":"Rachel K. Luu, M. Buehler","doi":"10.1115/1.4062310","DOIUrl":"https://doi.org/10.1115/1.4062310","url":null,"abstract":"\u0000 The analysis and design of materials is often a slow process that may take weeks, months, or years. And, many current material platforms rely on expensive raw material sources and fail to achieve sustainability goals. Meanwhile, bio-inspired Materials Informatics – fueled by emerging techniques such as multiscale modeling, machine learning and autonomous experimentation – is transforming the way materials are understood, discovered, developed, and selected. The impact of these tools is particularly noteworthy since they can be used to develop materials with fewer resources and with greater societal impact. A field that would strongly benefit from the use of Materials Informatics tools is that of structural biological materials, where mechanical properties are crucial for biological and engineering properties for species survival such as fracture resistant armor against predators, elastic recovery for repeated loadings, or mechanical actuation capacity. Generations of researchers have studied biological materials for their fascinating structure-property relationships that make up their impressive properties, including mechanical resilience. Despite the accumulation of scientific knowledge, relatively little has been translated to generating engineered bio-inspired materials. Addressing this gap, emerging Materials Informatics tools can now be used to make use of legacy data, newly collected empirical observations, and predictive models to make significant advances in this field.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48653691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Piezoelectric metamaterials have received extensive attention in fields of robotics, nondestructive testing, energy harvesting, etc. Natural piezoelectric ceramics possess only five nonzero piezoelectric coefficients due to the crystal symmetry of 8mm, which has limited the development of related devices. To obtain nonzero piezoelectric coefficients, previous studies mainly focus on assembling piezoelectric ceramic units or multiphase metamaterials. However, only part of the nonzero piezoelectric coefficients or locally piezoelectric electromechanical modes are achieved. Additionally, it still remains challenge for manipulating the piezoelectric coefficients in a wide range. In this work, full nonzero piezoelectric coefficients are obtained by symmetry breaking in architected piezoelectric metamaterial. The piezoelectric coefficients are designable over a wide range from positive to negative through manipulating the directions of the three-dimensional architected lattice. The architected metamaterials exhibit multiple positive/inverse piezoelectric modes, including normal, shear, and twist deformation in different directions. Finally, a smart gradient architected piezoelectric metamaterial is designed to take advantage of this feature, which can sense the position of the normal and shear force. This work paves the way for the control of piezoelectric metamaterial in a wide range with designable full nonzero piezoelectric coefficients, thereby enabling application potential in the fields of intelligent actuation and sensing.
{"title":"Architected Piezoelectric Metamaterial with Designable Full Nonzero Piezoelectric Coefficients","authors":"Bo Yu, Y. Lun, Zewei Hou, Jiawang Hong","doi":"10.1115/1.4062309","DOIUrl":"https://doi.org/10.1115/1.4062309","url":null,"abstract":"\u0000 Piezoelectric metamaterials have received extensive attention in fields of robotics, nondestructive testing, energy harvesting, etc. Natural piezoelectric ceramics possess only five nonzero piezoelectric coefficients due to the crystal symmetry of 8mm, which has limited the development of related devices. To obtain nonzero piezoelectric coefficients, previous studies mainly focus on assembling piezoelectric ceramic units or multiphase metamaterials. However, only part of the nonzero piezoelectric coefficients or locally piezoelectric electromechanical modes are achieved. Additionally, it still remains challenge for manipulating the piezoelectric coefficients in a wide range. In this work, full nonzero piezoelectric coefficients are obtained by symmetry breaking in architected piezoelectric metamaterial. The piezoelectric coefficients are designable over a wide range from positive to negative through manipulating the directions of the three-dimensional architected lattice. The architected metamaterials exhibit multiple positive/inverse piezoelectric modes, including normal, shear, and twist deformation in different directions. Finally, a smart gradient architected piezoelectric metamaterial is designed to take advantage of this feature, which can sense the position of the normal and shear force. This work paves the way for the control of piezoelectric metamaterial in a wide range with designable full nonzero piezoelectric coefficients, thereby enabling application potential in the fields of intelligent actuation and sensing.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44176642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evidence from cyclic tests on metals, elastomers and sandy soils reveals that damping forces are nearly rate-independent and structural (hysteretic or rate-independent) damping was widely adopted since the 1940s. While there is no time-domain constitutive equation for a linear spring connected in parallel with a rate-independent dashpot, the dynamic stiffness (transfer function) of this mechanical network can be constructed in the frequency-domain; and it was known since the early 1960s that this mechanical network exhibits a non-causal response. In view of its simplicity in association with the wide practical need to model rate-independent dissipation, this mechanical network was also implemented in time-domain formulations with the label complex stiffness where the force output, P(t) is related in the time-domain to the displacement input, u(t), with P(t) = k(1 + i η)u(t). This paper shows that the complex stiffness, as expressed in the time-domain by various scholars, is a fundamentally flawed construct since in addition to causality it violates equilibrium.
{"title":"Equilibrium Violation from the Complex Stiffness","authors":"N. Makris","doi":"10.1115/1.4062263","DOIUrl":"https://doi.org/10.1115/1.4062263","url":null,"abstract":"\u0000 Evidence from cyclic tests on metals, elastomers and sandy soils reveals that damping forces are nearly rate-independent and structural (hysteretic or rate-independent) damping was widely adopted since the 1940s. While there is no time-domain constitutive equation for a linear spring connected in parallel with a rate-independent dashpot, the dynamic stiffness (transfer function) of this mechanical network can be constructed in the frequency-domain; and it was known since the early 1960s that this mechanical network exhibits a non-causal response. In view of its simplicity in association with the wide practical need to model rate-independent dissipation, this mechanical network was also implemented in time-domain formulations with the label complex stiffness where the force output, P(t) is related in the time-domain to the displacement input, u(t), with P(t) = k(1 + i η)u(t). This paper shows that the complex stiffness, as expressed in the time-domain by various scholars, is a fundamentally flawed construct since in addition to causality it violates equilibrium.","PeriodicalId":54880,"journal":{"name":"Journal of Applied Mechanics-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47635790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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