International Journal of Mechanical Sciences最新文献_第2页

Dimensional change and springback of spherical shell in cryogenic forming 球形外壳在低温成形过程中的尺寸变化和回弹

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-10-04 DOI: 10.1016/j.ijmecsci.2024.109757

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.

低温成形已被开发用于制造薄壁曲面铝合金部件，其最终尺寸会受到低温收缩和回弹的影响。因此，对低温成形中球形外壳的尺寸变化进行了理论和实验研究。通过讨论低温成形过程，阐明了影响尺寸变化的因素。通过分析应力分布，定性地揭示了回弹行为。建立了低温尺寸测量装置，以定量评估冲压冷却、回弹和试样恢复到室温的成形过程中的尺寸变化。建立了弹性模量和膨胀系数的温度相关性模型，以定量计算热胀冷缩对试样和冲头尺寸的影响。理论分析结果表明，深度减小和开口扩张是由低温回弹产生的，由不同变形区域的径向应力、环向应力和弯矩决定。由于径向变形增大和弯曲变形减小，双轴拉伸应力区的低温回弹减少了 37.8%。相反，拉伸-压缩应力区的低温回弹增加了 30.8%。深度方向上的冲头冷却收缩和试样升温膨胀可以减少回弹造成的尺寸偏差，但在箍筋方向上却会造成相反的影响。利用提出的模型可以有效预测膨胀和收缩，误差小于 16%。双轴拉伸应力的变形区域可以通过在低温下显著提高的硬化能力而扩大，这有利于提高变形均匀性并进一步减少回弹。因此，低温成形为铝合金深腔薄壁部件的精密制造提供了巨大潜力。

{"title":"Dimensional change and springback of spherical shell in cryogenic forming","authors":"","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":null,"pages":null},"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}

引用次数: 0

Physics-informed deep learning for structural dynamics under moving load 移动载荷下结构动力学的物理信息深度学习

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-10-02 DOI: 10.1016/j.ijmecsci.2024.109766

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.

物理信息深度学习已成为一种很有前途的方法，它将物理约束纳入模型，减少了所需的数据量，在处理各种研究的有限数据集时表现出鲁棒性和潜力。然而，目前仍存在一些关键挑战，其中之一就是深度学习在模拟具有多频率特性的函数时存在频谱偏差问题。为了克服这一挑战，本研究提出了一种新颖的物理信息深度学习方法，该方法将物理信息神经网络与傅立叶变换相结合，从而求解频域偏微分方程，从而缓解了神经网络在模拟多频函数时的频谱偏差问题。此外，提出的方法还用于重点解决移动载荷下结构动力学的正演模拟和参数反演识别问题。为了说明该方法的优越性，以移动荷载下简单支撑梁的动态响应问题为案例，分析和讨论了该方法在多个案例中的性能。研究结果证明了该方法在利用有限数据集进行结构动力学模拟和参数反识别方面的可行性和有效性。

{"title":"Physics-informed deep learning for structural dynamics under moving load","authors":"","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":null,"pages":null},"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}

引用次数: 0

A 2-DOF piezoelectric platform for cross-scale semiconductor inspection 用于跨尺度半导体检测的 2-DOF 压电平台

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-10-01 DOI: 10.1016/j.ijmecsci.2024.109765

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.

为了应对半导体检测中实现大行程和高精度的挑战，本研究提出了一种新型 2-DOF 跨尺度压电定位平台。在半导体检测中，该平台利用椭圆、粘滑和直推驱动模式来满足毫米、微米和纳米尺度的运动要求。通过向压电单元施加确定的电信号，该平台可实现毫米尺度的高速连续模式（HCM）、微米尺度的低速步进模式（LSM）和纳米尺度的高精度定位模式（HPM）。对平台柔性定子的设计进行了理论分析和模拟，并分析了其动态特性。制作、组装和实验测试了原型，以研究拟议平台的机械性能。结果表明，原型成功实现了三种模式下的跨尺度运动：在 HCM 模式下实现了 62.47 mm/s 的最大空载速度；在 LSM 模式下实现了 14.62 μm/s 的低速步进运动；在 HPM 模式下实现了分辨率为 25 nm、范围在 ±21 μm 内的高精度定位。通过三种驱动模式的灵活切换和配合，该平台可以毫米级速度快速接近目标，并以微米级运动进一步接近，最终实现纳米级精度定位。最后，该定位平台被成功应用于半导体器件的缺陷检测。本研究探索了压电定位平台的新型跨尺度驱动方法，为半导体元件检测相关的精密操控研究提供了一种新方法。

{"title":"A 2-DOF piezoelectric platform for cross-scale semiconductor inspection","authors":"","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":null,"pages":null},"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}

引用次数: 0

Topological modes, vibration attenuation, and energy harvesting in electromechanical metastructures 机电转移结构中的拓扑模式、振动衰减和能量收集

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-10-01 DOI: 10.1016/j.ijmecsci.2024.109763

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.

本研究探讨了周期性和准周期性机电转移结构中拓扑边界模式的动力学，重点是其在能量收集和减震方面的应用。本研究分析的元结构基于分流压电贴片阵列，其电气参数根据一维 Aubry-André-Harper 模型进行调制。这种调制的结果是，在谐振器的中心频率附近产生了分形频谱，这是非琐碎拓扑结构的一个标志，它使数字可控边缘状态和随之而来的亚波长频率局部化现象得以出现。在此框架下，我们对元结构的光谱特性进行了详细分析，以研究调制参数对光束边界和内部模式局部化的影响。然后，结合系统的能量收集、衰减和波传输能力，对这种定位效应进行研究。这些功能指向实现具有低频和数字可控振动衰减能力的自供电结构，并被认为在涉及弹性波和振动的应用中具有重要的技术意义，在这些应用中，精确控制和利用这些现象的能力可为高能效和自适应系统带来创新解决方案。

{"title":"Topological modes, vibration attenuation, and energy harvesting in electromechanical metastructures","authors":"","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":null,"pages":null},"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}

引用次数: 0

A finite volume–based thermo-fluid-mechanical model of the LPBF process 基于有限体积的 LPBF 工艺热流体力学模型

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-29 DOI: 10.1016/j.ijmecsci.2024.109759

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.

激光粉末床熔融（LPBF）工艺的多物理场耦合特性对数值模型的计算保真度和效率提出了巨大挑战。本文提出了一种基于有限体积的模型，用于预测 LPBF 工艺的热-流-机综合行为。该模型将传热、流体流动和固体力学模拟直接统一在一个预定义网格中，实现了欧拉描述下的流体域和拉格朗日描述下的固体域的同步求解。为验证该模型的准确性和有效性，针对个别问题进行了三次基准测试。进行了轨道尺度 LPBF 模拟，以揭示热、流体和机械行为之间错综复杂的相互作用。对表面形态、熔池动态和熔轨尺寸的数值预测与实验观测结果十分吻合。瞬态热应力的时空演变被准确捕捉，预测的残余应力场与纳米压痕测量结果一致。发现所提出的模型在同时预测 LPBF 过程的温度分布、熔体流动和残余应力演变方面非常稳健，并显示出解决其他类似多物理场耦合问题的强大潜力。

{"title":"A finite volume–based thermo-fluid-mechanical model of the LPBF process","authors":"","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":null,"pages":null},"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}

引用次数: 0

T-matrix of piezoelectric shunt inclusions on a thin plate 薄板上压电分流夹杂物的 T 矩阵

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-29 DOI: 10.1016/j.ijmecsci.2024.109756

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。

{"title":"T-matrix of piezoelectric shunt inclusions on a thin plate","authors":"","doi":"10.1016/j.ijmecsci.2024.109756","DOIUrl":"10.1016/j.ijmecsci.2024.109756","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419518","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}

引用次数: 0

A continuous-discontinuous coupling computational method for multi-material mixtures 多材料混合物的连续-非连续耦合计算方法

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-29 DOI: 10.1016/j.ijmecsci.2024.109760

Considering the important role of particle-reinforced composites (PRCs), and to accurately assess the mechanical properties of PRC with arbitrarily complex internal structures, this paper proposes a new continuous-discontinuous coupled computational method, i.e., the multi-material integrated analysis (MIA) method, by combining the advantages of the discontinuous deformation analysis (DDA) method, the numerical manifold method (NMM), and the meshless method, for the continuous-discontinuous dual state of this kind of materials when they are subjected to forces. The core idea of this method is by establishing a single physical cover (PC) on each particle and defining a unified and piecewise approximation function over it to achieve displacement coordination between the particles and the matrix. In this model, the particles can maintain the contact and separation characteristics like the blocks, while the matrix is able to achieve the bonding function by overlapping different covers. Two numerical integration schemes, namely single-point Gaussian integration and Monte Carlo integration, are proposed to address the integration issues in stiffness matrix calculations. Meanwhile by considering the similarity between NMM and meshless method interpolation function construction, this paper combines circular coverage and 0th-order moving least squares to construct the interpolation function to form the displacement approximation function for the whole solution space. Moreover, the method of lattice retrieval (also Nearest Neighbor Search, NNS) is invoked for particle contact determination to improve the efficiency of contact and coverage relationship determination. The validity of the model is verified by taking asphalt mixture, a typical PRC, as a demonstrative case study. The results show that the MIA method solves the one-sided problem that the existing algorithms usually only consider the continuous or discontinuous properties of PRC, and provides a new method for comprehensively analyzing the micromechanical response of PRC and solving its large deformation problem.

考虑到颗粒增强复合材料（PRC）的重要作用，并为了准确评估具有任意复杂内部结构的PRC的力学性能，本文提出了一种新的连续-非连续耦合计算方法，即多材料综合分析（MIA）方法、本文结合非连续变形分析（DDA）方法、数值流形方法（NMM）和无网格方法的优点，提出了一种新的连续-非连续耦合计算方法，即多材料综合分析（MIA）方法，用于研究这类材料受力时的连续-非连续双重状态。该方法的核心思想是在每个粒子上建立一个单一的物理覆盖（PC），并在其上定义一个统一的分片近似函数，以实现粒子与基体之间的位移协调。在这个模型中，粒子可以像块体一样保持接触和分离特性，而基体则可以通过重叠不同的覆盖层来实现结合功能。针对刚度矩阵计算中的积分问题，提出了两种数值积分方案，即单点高斯积分和蒙特卡罗积分。同时，考虑到 NMM 与无网格法插值函数构造的相似性，本文结合圆形覆盖和 0 次移动最小二乘法构造插值函数，形成整个求解空间的位移近似函数。此外，本文还引用了网格检索法（也称近邻搜索法，NNS）进行粒子接触确定，以提高接触和覆盖关系确定的效率。以典型的沥青混合料为例，验证了该模型的有效性。结果表明，MIA 方法解决了现有算法通常只考虑沥青混合料连续或不连续特性的片面问题，为全面分析沥青混合料的微观力学响应和解决其大变形问题提供了一种新方法。

{"title":"A continuous-discontinuous coupling computational method for multi-material mixtures","authors":"","doi":"10.1016/j.ijmecsci.2024.109760","DOIUrl":"10.1016/j.ijmecsci.2024.109760","url":null,"abstract":"<div><div>Considering the important role of particle-reinforced composites (PRCs), and to accurately assess the mechanical properties of PRC with arbitrarily complex internal structures, this paper proposes a new continuous-discontinuous coupled computational method, i.e., the multi-material integrated analysis (MIA) method, by combining the advantages of the discontinuous deformation analysis (DDA) method, the numerical manifold method (NMM), and the meshless method, for the continuous-discontinuous dual state of this kind of materials when they are subjected to forces. The core idea of this method is by establishing a single physical cover (PC) on each particle and defining a unified and piecewise approximation function over it to achieve displacement coordination between the particles and the matrix. In this model, the particles can maintain the contact and separation characteristics like the blocks, while the matrix is able to achieve the bonding function by overlapping different covers. Two numerical integration schemes, namely single-point Gaussian integration and Monte Carlo integration, are proposed to address the integration issues in stiffness matrix calculations. Meanwhile by considering the similarity between NMM and meshless method interpolation function construction, this paper combines circular coverage and 0th-order moving least squares to construct the interpolation function to form the displacement approximation function for the whole solution space. Moreover, the method of lattice retrieval (also Nearest Neighbor Search, NNS) is invoked for particle contact determination to improve the efficiency of contact and coverage relationship determination. The validity of the model is verified by taking asphalt mixture, a typical PRC, as a demonstrative case study. The results show that the MIA method solves the one-sided problem that the existing algorithms usually only consider the continuous or discontinuous properties of PRC, and provides a new method for comprehensively analyzing the micromechanical response of PRC and solving its large deformation problem.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418494","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}

引用次数: 0

Experiment-in-the-Loop system for fast and effective tuning of active vibration controllers 用于快速有效调整主动振动控制器的环中实验系统

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-28 DOI: 10.1016/j.ijmecsci.2024.109753

Tuning active controllers is one of the main challenges in the field of active vibration control (AVC). To address this challenge, this study introduces a novel approach called Experiment in the Loop (EITL). The EITL method, unlike traditional techniques, automates the tuning process through an algorithm based on Particle Swarm Optimization (PSO). This algorithm carries out numerous experimental tests on a structure and, at each test, tries a new configuration of the controller, evaluates its performance, and iteratively improves the control parameters. The EITL's innovation lies in its ability to achieve fast and efficient tuning without any numerical model, making it a significant advancement in AVC technology. The EITL approach is validated by tuning five Multiple-Input Multiple-Output (MIMO) Positive Position Feedback (PPF) active vibration controllers on a composite beam equipped with three piezoelectric sensors and three piezoelectric actuators. Experimental results show that the ‖H‖_∞ norm of the composite beam is reduced up to 96.1% on certain modes, and an average reduction of 74.7% is achieved in a frequency range from 0 to 200 Hz with minimal spillover effects. The developed EITL opens the avenue to a fast and effective tuning of AVC without numerical models.

调整主动控制器是主动振动控制（AVC）领域的主要挑战之一。为应对这一挑战，本研究引入了一种名为 "环中实验（EITL）"的新方法。与传统技术不同，EITL 方法通过基于粒子群优化（PSO）的算法实现了调谐过程的自动化。该算法对结构进行多次实验测试，每次测试都会尝试新的控制器配置，评估其性能，并迭代改进控制参数。EITL 的创新之处在于无需任何数值模型即可实现快速高效的调整，这使其成为 AVC 技术的一大进步。通过在装有三个压电传感器和三个压电致动器的复合梁上调整五个多输入多输出（MIMO）正位置反馈（PPF）主动振动控制器，对 EITL 方法进行了验证。实验结果表明，复合梁的 "H"∞规范在某些模式下降低了 96.1%，在 0 到 200 Hz 的频率范围内平均降低了 74.7%，溢出效应最小。所开发的 EITL 为无需数值模型就能快速有效地调整 AVC 开辟了途径。

{"title":"Experiment-in-the-Loop system for fast and effective tuning of active vibration controllers","authors":"","doi":"10.1016/j.ijmecsci.2024.109753","DOIUrl":"10.1016/j.ijmecsci.2024.109753","url":null,"abstract":"<div><div>Tuning active controllers is one of the main challenges in the field of active vibration control (AVC). To address this challenge, this study introduces a novel approach called Experiment in the Loop (EITL). The EITL method, unlike traditional techniques, automates the tuning process through an algorithm based on Particle Swarm Optimization (PSO). This algorithm carries out numerous experimental tests on a structure and, at each test, tries a new configuration of the controller, evaluates its performance, and iteratively improves the control parameters. The EITL's innovation lies in its ability to achieve fast and efficient tuning without any numerical model, making it a significant advancement in AVC technology. The EITL approach is validated by tuning five Multiple-Input Multiple-Output (MIMO) Positive Position Feedback (PPF) active vibration controllers on a composite beam equipped with three piezoelectric sensors and three piezoelectric actuators. Experimental results show that the ‖<em>H</em>‖<sub>∞</sub> norm of the composite beam is reduced up to 96.1% on certain modes, and an average reduction of 74.7% is achieved in a frequency range from 0 to 200 Hz with minimal spillover effects. The developed EITL opens the avenue to a fast and effective tuning of AVC without numerical models.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418490","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}

引用次数: 0

Nonlinear dynamics of dielectric actuator: Exploring electrode mechanics 电介质致动器的非线性动力学：探索电极力学

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-28 DOI: 10.1016/j.ijmecsci.2024.109755

Dielectric elastomer (DE) is a smart material with various biomedical, soft robotics, and vibration control applications. Modeling of the DE actuator is essential for its practical applicability by virtue of its nonlinear characteristic. Many existing models neglect the effect of the electrode despite substantial experimental work demonstrating the electrode’s influence. This work presents the model and nonlinear analysis of the equi-biaxial motion of a planar dielectric membrane incorporating the effect of the electrode. The uniqueness of the paper is due to the inclusion of terms related to inertia, stiffness and damping of the electrode in the governing equation. The elastomer and the electrode are both assumed to be hyperelastic materials having different physical properties, and the governing equation is derived by considering the mechanical aspects of both the elastomer and electrode materials. The behavior of the system for both constant and time-varying voltages is analyzed. Static response and its dependence are explored by presenting the equilibrium stretch plot, potential energy characteristics, and the basin of attraction. The analysis is further expanded for the time-varying voltage, and the impact of the electrode material on the system’s stretch range is also demonstrated. Backward and forward frequency sweeps are used to obtain the amplitude–frequency response and show its dependence on the electrode. Furthermore, time response, phase plot, Poincare map, and Lyapunov exponent are utilized to demonstrate the impact of the mechanical characteristic of the elastomer and electrode on the overall dynamics. The proposed model is validated with the experiment for different voltage conditions. A comparison is also presented between the experiment and system behavior with and without the electrode effect. The findings indicate that the electrode influences the static and dynamic response of the actuator. This work gives a more realistic model of the DE actuator and guides more accurate design of the actuator for various applications.

介电弹性体（DE）是一种智能材料，在生物医学、软机器人和振动控制等领域有着广泛的应用。由于其非线性特性，电介质致动器的建模对其实际应用至关重要。尽管大量实验证明了电极的影响，但许多现有模型都忽略了电极的影响。本文介绍了包含电极效应的平面介电膜等轴向运动模型和非线性分析。本文的独特之处在于将与电极的惯性、刚度和阻尼有关的项纳入了控制方程。假设弹性体和电极都是具有不同物理性质的超弹性材料，并通过考虑弹性体和电极材料的机械特性推导出控制方程。分析了恒定电压和时变电压下的系统行为。通过展示平衡拉伸图、势能特征和吸引力盆地，探讨了静态响应及其依赖性。针对时变电压的分析得到了进一步扩展，同时还展示了电极材料对系统拉伸范围的影响。利用后向和前向频率扫描获得幅频响应，并显示其与电极的关系。此外，还利用时间响应、相位图、Poincare 地图和 Lyapunov 指数来证明弹性体和电极的机械特性对整体动力学的影响。提出的模型与不同电压条件下的实验进行了验证。此外，还对实验结果和有无电极效应的系统行为进行了比较。研究结果表明，电极会影响致动器的静态和动态响应。这项研究为 DE 激励器提供了一个更真实的模型，并为各种应用提供了更精确的激励器设计指导。

{"title":"Nonlinear dynamics of dielectric actuator: Exploring electrode mechanics","authors":"","doi":"10.1016/j.ijmecsci.2024.109755","DOIUrl":"10.1016/j.ijmecsci.2024.109755","url":null,"abstract":"<div><div>Dielectric elastomer (DE) is a smart material with various biomedical, soft robotics, and vibration control applications. Modeling of the DE actuator is essential for its practical applicability by virtue of its nonlinear characteristic. Many existing models neglect the effect of the electrode despite substantial experimental work demonstrating the electrode’s influence. This work presents the model and nonlinear analysis of the equi-biaxial motion of a planar dielectric membrane incorporating the effect of the electrode. The uniqueness of the paper is due to the inclusion of terms related to inertia, stiffness and damping of the electrode in the governing equation. The elastomer and the electrode are both assumed to be hyperelastic materials having different physical properties, and the governing equation is derived by considering the mechanical aspects of both the elastomer and electrode materials. The behavior of the system for both constant and time-varying voltages is analyzed. Static response and its dependence are explored by presenting the equilibrium stretch plot, potential energy characteristics, and the basin of attraction. The analysis is further expanded for the time-varying voltage, and the impact of the electrode material on the system’s stretch range is also demonstrated. Backward and forward frequency sweeps are used to obtain the amplitude–frequency response and show its dependence on the electrode. Furthermore, time response, phase plot, Poincare map, and Lyapunov exponent are utilized to demonstrate the impact of the mechanical characteristic of the elastomer and electrode on the overall dynamics. The proposed model is validated with the experiment for different voltage conditions. A comparison is also presented between the experiment and system behavior with and without the electrode effect. The findings indicate that the electrode influences the static and dynamic response of the actuator. This work gives a more realistic model of the DE actuator and guides more accurate design of the actuator for various applications.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329899","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}

引用次数: 0

Phase-field model of hydraulic fracturing in thermoelastic–plastic media 热塑性介质中的水力压裂相场模型

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences

Pub Date : 2024-09-27 DOI: 10.1016/j.ijmecsci.2024.109750

In this study, we present a thermodynamically consistent thermo-fluid–solid–elastic–plastic phase-field model to accurately capture the propagation process of hydraulic fracture in deep shale. The developed model takes into account the degradation of the thermoelastic–plastic parameters, strain hardening, mixed-mode fracture, and thermal convection. The model incorporates an uncorrelated Drucker–Prager constitutive model with a nonlinear saturated strain function to capture the deformation behavior of shale. The driving force of the fracture integrates the effects of elastic, plastic dissipative, fluid, and thermal energies of the rock. The model is constructed in a numerical computation iteration format using finite element discretization and Newton–Raphson iteration. To solve the coupled problem more efficiently, a staggered iteration algorithm is adopted to solve the displacement, pressure, temperature, and phase fields. Several numerical results are extracted and compared with the analytical solution results and experimental test data to demonstrate the accuracy and validity of the proposed model. In addition, the propagation behavior of hydraulic fractures in thermoelastic–plastic reservoirs with homogeneous, natural fractures or layering is investigated, and the results show that the model can capture complex fracture propagation patterns.

在本研究中，我们提出了一种热力学上一致的热流体-固体-弹塑性相场模型，以准确捕捉深层页岩中水力压裂的传播过程。所建立的模型考虑了热弹塑参数的退化、应变硬化、混合模式压裂和热对流。该模型采用了非相关德鲁克-普拉格构成模型和非线性饱和应变函数，以捕捉页岩的变形行为。断裂驱动力综合了岩石的弹性能、塑性耗散能、流体能和热能的影响。该模型采用有限元离散化和牛顿-拉斐森迭代的数值计算迭代格式。为了更有效地解决耦合问题，采用了交错迭代算法来求解位移、压力、温度和相场。提取了若干数值结果，并与分析求解结果和实验测试数据进行了比较，以证明所提模型的准确性和有效性。此外，还研究了具有均质天然裂缝或分层的热弹塑性储层中水力裂缝的传播行为，结果表明该模型能够捕捉复杂的裂缝传播模式。

{"title":"Phase-field model of hydraulic fracturing in thermoelastic–plastic media","authors":"","doi":"10.1016/j.ijmecsci.2024.109750","DOIUrl":"10.1016/j.ijmecsci.2024.109750","url":null,"abstract":"<div><div>In this study, we present a thermodynamically consistent thermo-fluid–solid–elastic–plastic phase-field model to accurately capture the propagation process of hydraulic fracture in deep shale. The developed model takes into account the degradation of the thermoelastic–plastic parameters, strain hardening, mixed-mode fracture, and thermal convection. The model incorporates an uncorrelated Drucker–Prager constitutive model with a nonlinear saturated strain function to capture the deformation behavior of shale. The driving force of the fracture integrates the effects of elastic, plastic dissipative, fluid, and thermal energies of the rock. The model is constructed in a numerical computation iteration format using finite element discretization and Newton–Raphson iteration. To solve the coupled problem more efficiently, a staggered iteration algorithm is adopted to solve the displacement, pressure, temperature, and phase fields. Several numerical results are extracted and compared with the analytical solution results and experimental test data to demonstrate the accuracy and validity of the proposed model. In addition, the propagation behavior of hydraulic fractures in thermoelastic–plastic reservoirs with homogeneous, natural fractures or layering is investigated, and the results show that the model can capture complex fracture propagation patterns.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":null,"pages":null},"PeriodicalIF":7.1,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329900","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}

引用次数: 0