Extreme Mechanics Letters最新文献

Brittle fracture of ultrathin gold nanosheets induced by local phase change and energy dissipation

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-04-04 DOI: 10.1016/j.eml.2025.102323

Jieun Park , Guh-Hwan Lim , Dayoung Yoo , Tae-Hoon Kim , Jong-Man Kim , Cheol-Woong Yang , Joonkyung Jang , Yoon Suk Choi , Byunkwon Lim , Jeffrey W. Kysar , Dongyun Lee

{"title":"Brittle fracture of ultrathin gold nanosheets induced by local phase change and energy dissipation","authors":"Jieun Park , Guh-Hwan Lim , Dayoung Yoo , Tae-Hoon Kim , Jong-Man Kim , Cheol-Woong Yang , Joonkyung Jang , Yoon Suk Choi , Byunkwon Lim , Jeffrey W. Kysar , Dongyun Lee","doi":"10.1016/j.eml.2025.102323","DOIUrl":"10.1016/j.eml.2025.102323","url":null,"abstract":"<div><div>Metals with a face-centered cubic (<em>fcc</em>) structure, such as gold (Au), are generally known for their excellent ductility. However, in this study, we observed a novel brittle fracture behavior in ultrathin Au nanosheets with a thickness of approximately 15 nm and a diagonal length of up to 80 μm, synthesized via an aqueous solution method. Nanoindentation experiments on these nanosheets revealed a unique fracture pattern, characterized by crack propagation at angles of 120° from the indentation point. Molecular dynamics (MD) simulations replicated this unusual behavior, attributing it to a localized phase transformation from the <em>fcc</em> to hexagonal close-packed (<em>hcp</em>) structure under external stress. We hypothesize that this phase transition is initiated by stacking faults introduced during the nanosheet fabrication process. The observed brittle fracture is further influenced by an energy dissipation mechanism, as evidenced by the formation of slip lines around the fracture site. Our findings suggest that even in ductile metals like Au, brittle fracture can occur due to localized phase changes and energy dissipation. This study provides new insights into the mechanical behavior of ultrathin Au nanosheets, with implications for their application in nanoelectronics and other advanced technologies.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"77 ","pages":"Article 102323"},"PeriodicalIF":4.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simple models of viscoelastic fibrillar adhesion to a rigid sphere

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-28 DOI: 10.1016/j.eml.2025.102316

X.M. Liang , G.F. Wang , M. Ciavarella

{"title":"Simple models of viscoelastic fibrillar adhesion to a rigid sphere","authors":"X.M. Liang , G.F. Wang , M. Ciavarella","doi":"10.1016/j.eml.2025.102316","DOIUrl":"10.1016/j.eml.2025.102316","url":null,"abstract":"<div><div>The SPG (Schargott–Popov–Gorb) model of independent elastic fibrils in adhesive contact with a rigid sphere is a simple model of bioinspired adhesives, which with remarkable simplicity explains the preload dependence of pull-off and saturation when the compressive force is sufficiently high. However, typical materials of fibrils are viscoelastic, so we extend the model to consider viscoelastic behavior using a standard material model for each fibril. We use for the condition of nucleation of fibril detachment either the classical Schapery model or a more recent proposal by Shrimali and Lopez-Pamies. In either case, starting from a relaxed compressive contact, we find that the pull-off force also strongly depends on preload and is amplified by faster unloading rates, very differently for the two theories. A propagation theory follows for the Schapery model which seems to link the effective work of adhesion on contact retraction speed where the characteristic velocity has however nothing to do with the classical Schapery propagation theory, whereas the Shrimali and Lopez-Pamies model leads to detachment without a real prior phase of propagation. Some results are compared with those in the literature.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"77 ","pages":"Article 102316"},"PeriodicalIF":4.3,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

The effect of electro-momentum coupling on unidirectional zero reflection in layered generalized Willis Metamaterials

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-27 DOI: 10.1016/j.eml.2025.102318

Hai D. Huynh , S.S. Nanthakumar , Harold S. Park , Timon Rabczuk , Xiaoying Zhuang

引用次数: 0

Multi-axed phase-transforming cellular material: A data-driven design and validation using finite-element method and machine learning

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-26 DOI: 10.1016/j.eml.2025.102319

Masayuki Okugawa , Sosuke Kanegae , Yuichiro Koizumi

{"title":"Multi-axed phase-transforming cellular material: A data-driven design and validation using finite-element method and machine learning","authors":"Masayuki Okugawa , Sosuke Kanegae , Yuichiro Koizumi","doi":"10.1016/j.eml.2025.102319","DOIUrl":"10.1016/j.eml.2025.102319","url":null,"abstract":"<div><div>We developed the novel Atom-Mimetic Cube-Diagonally Multi-Axed Phase-Transforming Cellular Material (AMCDMA-PXCM), hereafter AM-PXCM for short, for a multi-axial bistable metamaterial designed with inspiration from a face-centered cubic (FCC) crystal structure: the designed AM-PXCM consists of spheres at atomic positions of structure and dogleg-shaped beams connecting nearest neighbor spheres. Stress-strain relationship of AM-PXCM was investigated by Finite Element Method (FEM) simulation. Analyzing the results by Logistic classification revealed that the mechanical properties significantly depend on the designing parameters and the distance between the beam and the tetrahedron (<em>k</em>) dominantly determines the bistability of the FCC-based AM-PXCM. In addition, combined with the machine learning method (i.e., inverse design), we succeeded to predict the designing parameters to have the desired mechanical properties for a bistable metamaterial. The designed AM-PXCMs were realized using a 3D printer and validified to show the predicted mechanical properties. This established method for developing AM-PXCM is suggested to be also applied to a development of an AM-PXCM with the symmetry of other crystal structures.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"77 ","pages":"Article 102319"},"PeriodicalIF":4.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Piezoelectric gauge transformation for inverse design of polar Willis transducers

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-22 DOI: 10.1016/j.eml.2025.102315

Li Huang , Rui Zhu , Gengkai Hu , Yangyang Chen

{"title":"Piezoelectric gauge transformation for inverse design of polar Willis transducers","authors":"Li Huang , Rui Zhu , Gengkai Hu , Yangyang Chen","doi":"10.1016/j.eml.2025.102315","DOIUrl":"10.1016/j.eml.2025.102315","url":null,"abstract":"<div><div>Piezoelectric lattices with delicately designed microscopic geometry are powerful building blocks to construct integrated sensors and actuators with versatile, yet unconventional, responses absent from bulk materials. However, the inverse design of the microscopic geometry to achieve a sought-after electromechanical response remains elusive. Here, we suggest an analytical approach, called <em>piezoelectric gauge transformation</em>, to design piezoelectric lattice transducers that can deform to an arbitrary desired displacement field when a voltage is applied. We first develop continuum piezoelectric gauge transformation and find that the transformed piezoelectric material displays piezoelectric polarity and Willis coupling in the sense that the applied electric field generates asymmetric stress and body force, and both rigid body rotation and translation induce electric charges. To design this polar and Willis-type piezoelectric material, we develop discrete piezoelectric gauge transformation and propose feasible lattice design guidelines. Numerical simulations are performed to validate the piezoelectric gauge transformation and demonstrate a range of appealing displacement control functions. The study presents a complete theoretical framework for the inverse design of lattice transducers to achieve arbitrary desired actuated displacement fields, beneficial to the development of soft actuators, robotics, and other piezoelectric devices.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"77 ","pages":"Article 102315"},"PeriodicalIF":4.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical strength across metastatic lesions in trabecular bone: The interplay of microstructure and composition

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-19 DOI: 10.1016/j.eml.2025.102317

Hanwen Fan , Hutomo Tanoto , Po-Ting Lin , Flordeliz Bowles , Shu Zhang , Zhonglin Liu , Feng Li , Eric O. Klineberg , Yuxiao Zhou

{"title":"Mechanical strength across metastatic lesions in trabecular bone: The interplay of microstructure and composition","authors":"Hanwen Fan , Hutomo Tanoto , Po-Ting Lin , Flordeliz Bowles , Shu Zhang , Zhonglin Liu , Feng Li , Eric O. Klineberg , Yuxiao Zhou","doi":"10.1016/j.eml.2025.102317","DOIUrl":"10.1016/j.eml.2025.102317","url":null,"abstract":"<div><div>Pathological bone fractures are a prevalent complication associated with metastatic cancer. However, the fragility associated with bone metastasis exhibits distinct characteristics that are not adequately addressed by current fracture risk assessment systems, which are primarily designed for osteoporosis. To understand how metastasis impairs trabecular bone strength, we experimentally measured mechanical strain across osteolytic and osteoblastic metastatic lesions under axial compression using mechanical testing coupled with micro-computed tomography (micro-CT) and digital volume correlation (DVC) method. We then attempted to evaluate the correlation between this mechanical strain and various parameters, including bone microstructure, bone mineral density, and bone fat-water concentration with the presence of trabecular bone, as assessed through high-resolution micro-CT and magnetic resonance imaging (MRI). This proof-of-concept study demonstrates a workflow that integrates mechanical testing and medical imaging data, enabling the potential to develop a quantitative correlation between local bone strength and the microstructural and compositional parameters measurable through medical imaging techniques. This innovative approach is helpful for identifying key factors influencing mechanical strength of metastatic bones and provides valuable insights for the development of new fracture risk assessment protocols for cancer patients.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"76 ","pages":"Article 102317"},"PeriodicalIF":4.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Collision resistant study of spherical tensegrity structures for protective drone shells

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-13 DOI: 10.1016/j.eml.2025.102312

Yaoyao Zhang , Kexin Zheng , Yi Zhao , Zhiyuan Zheng , Bingxing Chen , Muhao Chen

引用次数: 0

Modeling and control of coupled soft viscoelastic actuators based on sparse identification method

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-12 DOI: 10.1016/j.eml.2025.102309

Jisen Li , Anjing Cheng , Hao Wang, Zhipeng Xu, Jian Zhu

{"title":"Modeling and control of coupled soft viscoelastic actuators based on sparse identification method","authors":"Jisen Li , Anjing Cheng , Hao Wang, Zhipeng Xu, Jian Zhu","doi":"10.1016/j.eml.2025.102309","DOIUrl":"10.1016/j.eml.2025.102309","url":null,"abstract":"<div><div>Dielectric elastomer actuators (DEAs) are extensively employed as artificial muscles in bioinspired soft robotics due to their large voltage-induced deformations and muscle-like characteristics. Achieving complex, multiple degree of freedom(DOF) motions often requires coupling multiple DEAs. However, modeling and controlling coupled DEAs pose significant challenges due to their inherently nonlinear response, driven by factors such as rate-dependent viscoelasticity, design irregularities, and complex interactions among adjacent actuators. This study presents a comprehensive framework for the modeling and control of multiple coupled DEAs, leveraging a sparse identification approach to derive explicit governing equations that effectively describe the viscoelastic and coupling effects from experimental data. Using these identified equations, we design a model predictive controller (MPC) that enables precise trajectory tracking across a range of motion profiles. The proposed framework is validated through tracking experiments on DEAs with two DOFs, demonstrating its effectiveness and robustness. This approach offers a novel pathway for uncovering the underlying physics of coupled DEAs, with the potential to enhance the functional capabilities of DEA-driven soft robotic systems.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"76 ","pages":"Article 102309"},"PeriodicalIF":4.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DNN-based inverse design of line heating patterns for automated plate forming in shipbuilding using multi-start convex optimization

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-06 DOI: 10.1016/j.eml.2025.102313

Hyeonbin Moon , Kundo Park , Jaemin Lee , Donggi Lee , Seunghwa Ryu

{"title":"DNN-based inverse design of line heating patterns for automated plate forming in shipbuilding using multi-start convex optimization","authors":"Hyeonbin Moon , Kundo Park , Jaemin Lee , Donggi Lee , Seunghwa Ryu","doi":"10.1016/j.eml.2025.102313","DOIUrl":"10.1016/j.eml.2025.102313","url":null,"abstract":"<div><div>Line heating is a widely used plate forming technique in the shipbuilding industry, where steel plates are heated along specified paths to achieve desired deformations. Traditionally, the design of these heating patterns relies on the expertise of skilled workers due to the complex and nonlinear relationship between the heating patterns and the resultant plate deformations. This reliance often results in inconsistent productivity and quality. This study presents a data-driven inverse design framework that automates the optimization of line heating patterns for specified plate deformations, addressing the need for rapid and systematic methodologies. A deep neural network (DNN) trained on finite element method (FEM) simulation data, which validated against experimental results, is employed to model the relationship between initial plate geometry, line heating patterns, and resultant deformations. This surrogate model enables rapid predictions of deformed plate shapes. Utilizing the trained DNN, a multi-start convex optimization process is employed to identify the optimal line heating patterns for any given initial plate geometry and desired deformation. The proposed framework demonstrates significant potential for various engineering inverse design applications requiring prompt and accurate results, as validated by designing line heating patterns for 800 different plate shapes, achieving desired deformations not included in the training data.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"76 ","pages":"Article 102313"},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tiny scale defect contour recognition on curved structure based on electromagnetic thermography

IF 4.3 3区工程技术

Extreme Mechanics Letters Pub Date : 2025-03-03 DOI: 10.1016/j.eml.2025.102311

Lihua Guo , Wei Guo , Ling He , Liming Chen , Yue Li , Shunping Yan , Qiang Wan , Shejuan Xie , Zhenmao Chen

{"title":"Tiny scale defect contour recognition on curved structure based on electromagnetic thermography","authors":"Lihua Guo , Wei Guo , Ling He , Liming Chen , Yue Li , Shunping Yan , Qiang Wan , Shejuan Xie , Zhenmao Chen","doi":"10.1016/j.eml.2025.102311","DOIUrl":"10.1016/j.eml.2025.102311","url":null,"abstract":"<div><div>Precision spherical pressure vessels are used in critical pressure-bearing structures due to their excellent structural strength. The surface of the spherical shell may experience corrosion in long-term service, leading to the formation of tiny pitting defects, which cause a risk to the structural integrity. A high-precision, non-destructive method is required for tiny defects detecting and contour recognition. In this paper, firstly, a new sensor consisting of a rotatable yoke and spherical adaptive flexible material with high permeability (FMHP) is designed to improve the performance of the electromagnetic thermography, which achieves the detection of tiny scale defects in spherical shell surface with diameter of 40μm. Secondly, super-resolution algorithms based on machine learning and deep learning are developed to realize the contour recognition of tiny defects, indicating that the generative adversarial network has an optimum performance. Then, to address the distortion phenomenon in infrared imaging of spherical structures, a coordinate transformation-based image correction algorithm is developed, enabling the accurate reconstruction of defect contours.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"76 ","pages":"Article 102311"},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0