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

Efficient dataset generation for inverse design of micro-perforated sonic crystals

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-25 DOI: 10.1016/j.ijmecsci.2025.110190

Yapeng Li , Yonghang Sun , Junzhe Zhu , Yung Boon Chong , Kian Meng Lim , Heow Pueh Lee

{"title":"Efficient dataset generation for inverse design of micro-perforated sonic crystals","authors":"Yapeng Li , Yonghang Sun , Junzhe Zhu , Yung Boon Chong , Kian Meng Lim , Heow Pueh Lee","doi":"10.1016/j.ijmecsci.2025.110190","DOIUrl":"10.1016/j.ijmecsci.2025.110190","url":null,"abstract":"<div><div>Micro-perforated panels (MPPs) used as scatterers in sonic crystals (SCs) provide design flexibility for acoustic applications. Achieving the sound attenuation within a specified frequency range requires an inverse design procedure that refines the geometric parameters of MPP-SCs. Although data-driven methods show considerable promise for solving such inverse design problems, the generation of a large, well-labeled dataset of MPP-SCs remains computationally intensive, posing a critical bottleneck in deep learning-assisted design of periodic structures. To evaluate the acoustic attenuation properties of MPP-SCs, their complex band structures are computed using the Finite Element Method (FEM). In order to enhance computational efficiency, an Interpolated Bloch Mode Synthesis (Interpolated BMS) method is developed within the FEM framework. This method integrates conventional BMS with the matrix interpolation technique. Specifically, the Craig-Bampton method is employed to reduce interior degrees of freedom (DOFs), while a B-spline-based approach is proposed for reducing boundary DOFs. Both steps decrease the dimensionality of the eigenvalue problem involved in calculating the complex band structure, thereby reducing the computational time from 14.86 s to 1.11 s without sacrificing numerical accuracy. Subsequently, matrix interpolation is applied to estimate the reduced global matrices, thereby eliminating the need for re-meshing and re-assembling the matrices when the geometric parameters of the MPP-SCs are adjusted. As a result, the efficiency of training sample generation is enhanced by a factor of 14.4 compared to commercial software. The dataset generated by the proposed method is then utilized to determine the geometric parameters of the MPP-SCs through either meta-heuristic algorithms or a conditional generative neural network. Experiments are also conducted to verify the numerical results and the inverse design results.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"293 ","pages":"Article 110190"},"PeriodicalIF":7.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761118","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 bioinspired gradient curved auxetic honeycombs with enhanced energy absorption

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-25 DOI: 10.1016/j.ijmecsci.2025.110189

Jinlong Liu , Jiahui Liu , Kang Gao , Iman Mohagheghian , Wei Fan , Jie Yang , Zhangming Wu

{"title":"A bioinspired gradient curved auxetic honeycombs with enhanced energy absorption","authors":"Jinlong Liu , Jiahui Liu , Kang Gao , Iman Mohagheghian , Wei Fan , Jie Yang , Zhangming Wu","doi":"10.1016/j.ijmecsci.2025.110189","DOIUrl":"10.1016/j.ijmecsci.2025.110189","url":null,"abstract":"<div><div>Traditional auxetic honeycombs often exhibit reduced energy absorption capabilities due to global instability arising from shear band formation, significantly limiting their practical applications. To address this limitation, this study presents the Auxetic Arc-Curved Honeycomb with a novel Bioinspired Layering Gradient (BLG-AACH). The innovative gradient design of the BLG-AACH is inspired by the dense exterior and sparse interior characteristics of biological tissues across multiple scales, utilizing fractal self-similar structure to achieve this biological trait. The BLG-AACH facilitates induced deformation in the intermediate layers, thereby preventing overall global buckling and significantly enhancing energy absorption properties. The compressive behavior of the BLG-AACH was investigated through both experimental testing and finite element modeling. The results demonstrate that the BLG-AACH structure maintains a stable concave folding deformation mode and exhibits multi-level energy absorption capabilities. Its specific energy absorption and total energy absorption are 5.81 and 10.74 times greater than those of the homogeneous AACH, respectively, outperforming other layered configurations. Moreover, the BLG-AACH is highly programmable, enabling the adjustment of mechanical properties such as initial stiffness, plateau stress, and specific energy absorption by varying parameters like cell angle and cell wall thickness. Additionally, Genetic Programming-Symbolic Regression (GP-SR) was innovatively employed to derive a compact and scalable formula for calculating the specific energy absorption of the BLG-AACH, achieving an impressive <em>R<sup>2</sup></em> value of 0.99. These findings provide a novel paradigm for enhancing the energy absorption performance and its calculation in auxetic honeycombs.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110189"},"PeriodicalIF":7.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734833","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

Bio-inspired flapping wing design via a multi-objective optimization approach based on variable periodic Voronoi tessellation

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-25 DOI: 10.1016/j.ijmecsci.2025.110160

Zeyang Li , Kang Gao , Zhangming Wu

{"title":"Bio-inspired flapping wing design via a multi-objective optimization approach based on variable periodic Voronoi tessellation","authors":"Zeyang Li , Kang Gao , Zhangming Wu","doi":"10.1016/j.ijmecsci.2025.110160","DOIUrl":"10.1016/j.ijmecsci.2025.110160","url":null,"abstract":"<div><div>This paper introduces a novel bio-inspired design methodology for flapping wings in Micro Air Vehicles aiming for achieving optimal physical properties and enhanced aerodynamic performance. The wing’s truss structures are derived through a specialized non-periodic, meso-micro scale porous structure optimization technique, termed the “Variable-Periodic Voronoi Tessellation (VPVT)” method. By incorporating critical physical properties such as compliance, natural frequency, and mass transfer efficiency, the VPVT method transforms the complex design metrics into a standard multi-objective optimization process. This approach produces a biomimetic wing design with high geometric fidelity to insect wings. The optimized VPVT design demonstrates notable physical performance improvements over natural wing samples, resulting in a 19.6% increase in stiffness, a 12.5% rise in natural frequency, and a 5.2% enhancement in mass transfer efficiency. Later, the aerodynamic performance is further evaluated via fluid–structure coupling finite element (FE) simulations. Compared to conventional commercial design, the VPVT wing exhibits optimally-tailored local stiffness, resulting in improved aeroelastic behavior during gliding action. Specifically, the FE simulations demonstrate a 7.3% reduction in drag at low angles of attack and a 9.9% increase in lift at high angles of attack. These results indicate the high energy efficiency and maneuverability of the proposed design approach, which enables the design of micro aerial vehicles (MAVs) with long duration and complex maneuverability.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110160"},"PeriodicalIF":7.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704760","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

Ultrasonic vibration enhanced friction stir welding of titanium to aluminum

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-25 DOI: 10.1016/j.ijmecsci.2025.110191

Xiankun Zhang , Fengyuan Zhao , Long Li , Lei Shi , Chuansong Wu , Ashish Kumar , Sergey Mironov

{"title":"Ultrasonic vibration enhanced friction stir welding of titanium to aluminum","authors":"Xiankun Zhang , Fengyuan Zhao , Long Li , Lei Shi , Chuansong Wu , Ashish Kumar , Sergey Mironov","doi":"10.1016/j.ijmecsci.2025.110191","DOIUrl":"10.1016/j.ijmecsci.2025.110191","url":null,"abstract":"<div><div>Ti/Al hybrid structures offer advantages in lightweight design and cost reduction, but joining them is challenging due to differences in thermophysical properties. Friction stir welding (FSW) is a promising method but often leads to insufficient material flow and lack of penetration defects due to the need for low heat input to minimize intermetallic compounds (IMCs). To address these issues, ultrasonic vibration-enhanced friction stir welding (UVeFSW) was proposed for joining Ti/Al dissimilar materials in this study. The synergistic mechanism of ultrasonic vibration on the microstructure evolution and mechanical properties of Ti/Al dissimilar FSWed joints were systematically studied by multi-scale simulations and experiments. It shows that ultrasonic vibration promotes vertical material flow, reducing lack of penetration defects and enhancing mechanical properties. Transmission electron microscopy (TEM) analysis confirmed the formation of Al<sub>18</sub>Ti<sub>2</sub>Mg<sub>3</sub> and Al<sub>3</sub>Ti at the interface, with molecular dynamics simulations indicating that Al<sub>3</sub>Ti has higher interfacial strength. Ultrasonic vibration facilitates Ti diffusion, promoting the transformation of Al<sub>18</sub>Ti<sub>2</sub>Mg<sub>3</sub> into Al<sub>3</sub>Ti and alleviating micro-stress concentration caused by excessive lattice mismatch. This highlights novel insights into the beneficial role of ultrasonic vibration in FSW process. UVeFSW addresses a critical challenge in Ti/Al FSW process by achieving an optimal balance between low heat input and adequate material flow, improving joint strength by 16.8 %, reaching 330.9 MPa. These results highlight the potential of UVeFSW for joining Ti/Al hybrid structures, offering valuable theoretical and practical insights for advanced engineering applications.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110191"},"PeriodicalIF":7.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738314","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

Strain rate dependent ductile fracture behavior of Q960 ultra-high-strength steel

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-25 DOI: 10.1016/j.ijmecsci.2025.110183

Mingxu Shang , Hua Yang

{"title":"Strain rate dependent ductile fracture behavior of Q960 ultra-high-strength steel","authors":"Mingxu Shang , Hua Yang","doi":"10.1016/j.ijmecsci.2025.110183","DOIUrl":"10.1016/j.ijmecsci.2025.110183","url":null,"abstract":"<div><div>Predicting the ductile fracture behavior of ultra-high-strength structural steels under high-speed loading remains a significant challenge in impact engineering within civil engineering. In this study, the strain rate effect on the ductile fracture behavior of Q960 ultra-high-strength structural steel, which is stress-state dependent, is reported for the first time. In the testing programme, four types of stress-state-dependent specimens were designed and tested, including uniaxial tension, notched tension, plane strain tension and pure shear specimens. These specimens were subjected to five nominal strain rates: 10<sup>−3</sup> s<sup>−1</sup>, 10<sup>−1</sup> s<sup>−1</sup>, 10<sup>0</sup> <em>s</em><sup>−1</sup>, 10<sup>1</sup> s<sup>−1</sup>, 10<sup>2</sup> s<sup>−1</sup>. The shear-dominated fracture strain decreased sharply with increasing strain rate, even exhibiting a brittle trend at intermediate strain rates. To accurately describe the plasticity behavior undergoing large deformation at intermediate strain rates, a stress-state-dependent plasticity model was implemented in conjunction with a deformation resistance model that accounts for strain hardening, strain rate effect, and thermal softening under adiabatic conditions. Accordingly, the loading paths to fracture for all specimens at different strain rates, i.e., the evolution of the equivalent plastic strain in terms of the stress triaxiality, the Lode angle parameter and the equivalent plastic strain rate, were extracted based on a hybrid experimental-numerical approach. To characterize the stress-state-dependent effect of strain rate on fracture strain, a new rate-dependent Hosford-Coulomb ductile fracture initiation model was proposed to capture this specific strain-rate-induced mechanism. With calibrated parameters in a user-defined material subroutine, the proposed rate-dependent Hosford-Coulomb fracture model was successfully validated based on the experimental results.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"293 ","pages":"Article 110183"},"PeriodicalIF":7.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739175","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

Practical flutter speed formulas for structures with mass unbalance

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI: 10.1016/j.ijmecsci.2025.110182

Zuopeng Wen , Genshen Fang , Yaojun Ge

{"title":"Practical flutter speed formulas for structures with mass unbalance","authors":"Zuopeng Wen , Genshen Fang , Yaojun Ge","doi":"10.1016/j.ijmecsci.2025.110182","DOIUrl":"10.1016/j.ijmecsci.2025.110182","url":null,"abstract":"<div><div>Clarifying the evolution mechanism of flutter speed through simple formulas has long been challenging due to complex coupling mechanisms and numerous system parameters, particularly for structures with mass unbalance, e.g., airfoils, flutter-based energy harvesting (FEH) systems, and transmission line conductors. This study addresses the challenge by deriving explicit formulas for flutter speed in a vertical-torsional coupled system, offering a systematic framework to analyze flutter evolution. Verified experimentally and numerically, the formulas explicitly explain why flutter speed reaches a global minimum when the mass center is slightly downstream of elastic center and the torsional-to-vertical frequency ratio is slightly above unity. Moving the mass center upstream sharply increases flutter speed until flutter ceases, while shifting it further downstream results in a more gradual rise. The global minimum flutter speed is predicted to be proportional to torsional frequency and weakly influenced by mass ratio; the existence of mass unbalance reduces this flutter speed by up to 36%. Structural damping strongly affects flutter speed near the global minimum but has less impact at large mass unbalance. Analytical solutions of flutter speed sensitivity to parameters are also derived. These formulas provide a practical predictive tool for flutter analysis, reducing reliance on wind tunnel testing and simulations, while offering clear guidelines for the design and optimization of flutter-prone structures and FEH systems.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110182"},"PeriodicalIF":7.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738495","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

Industrial-scale manufactured acoustic metamaterials for multi-bandgap sound reduction

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI: 10.1016/j.ijmecsci.2025.110184

Xiaole Wang , Ping Sun , Xin Gu , Siqi Xu , Xudong Luo , Zhenyu Huang

{"title":"Industrial-scale manufactured acoustic metamaterials for multi-bandgap sound reduction","authors":"Xiaole Wang , Ping Sun , Xin Gu , Siqi Xu , Xudong Luo , Zhenyu Huang","doi":"10.1016/j.ijmecsci.2025.110184","DOIUrl":"10.1016/j.ijmecsci.2025.110184","url":null,"abstract":"<div><div>Achieving mass manufacturability and convenient deployability is the cornerstone to enable the widespread adoption of acoustic metamaterials. This work is poised to address the current challenges associated with manufacturing and deploying acoustic metamaterials. The proposed acoustic metamaterials comprise the resonant and mounting parts assembled through stud-and-tube coupling. The resonant part consists of multiple unit cells connected by slender rods, and each unit cell contains four cantilever beam-type resonators with different geometric parameters for generating multiple bandgaps. The back side of the mounting part is flat and broad, facilitating the quick and secure attachment of the acoustic metamaterials on the surface of the host structure. The injection molding technique is employed to mass-produce the acoustic metamaterial specimens made of the Acrylonitrile Butadiene Styrene material. After that, the static mechanical characteristics of the acoustic metamaterial specimens are experimentally quantified by assessing the withstand tensile and compressive forces. Next, the underlying physics behind the dynamic mechanical characteristics of the acoustic metamaterial specimens are revealed by utilizing a combination of analytic, numerical, and experimental techniques. Finally, the acoustic metamaterial specimens deployed on a scaled-down aircraft cabin model are tested to verify the sound reduction effects in large-size and complex wave field environments. We find that the acoustic metamaterial specimens exhibit four complete locally-resonant bandgaps below 500 Hz, allowing multi-bandgap reduction of both air-borne and structure-borne noise. Our unique design of the multi-bandgap acoustic metamaterials and the practical prototypes manufactured at an industrial scale through injection molding represent a significant advancement toward the commercialization of acoustic metamaterials.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"293 ","pages":"Article 110184"},"PeriodicalIF":7.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725855","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

Coupled vibration model-driven intelligent fault diagnosis in canned motor pumps

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI: 10.1016/j.ijmecsci.2025.110181

Jintao Yao , Taibo Yang , Zhihao Bi , Jiaxin Liu , Qingbo He , Zhike Peng

{"title":"Coupled vibration model-driven intelligent fault diagnosis in canned motor pumps","authors":"Jintao Yao , Taibo Yang , Zhihao Bi , Jiaxin Liu , Qingbo He , Zhike Peng","doi":"10.1016/j.ijmecsci.2025.110181","DOIUrl":"10.1016/j.ijmecsci.2025.110181","url":null,"abstract":"<div><div>Canned motor pumps have an unobservable internal structure, making it impossible to directly monitor their operational states or measure the transfer function from internal excitations to casing vibrations. This limitation poses significant challenges in accurately linking internal faults to measurable external signals. To address this issue, this study establishes a coupled vibration model of the canned motor pump to describe the transmission process from impeller hydraulic excitation to casing vibrations. Based on this model, four fault dynamic models are developed to simulate casing vibrations under different fault conditions, supporting fault mechanism analysis. Additionally, a model-based intelligent diagnostic framework is proposed, enabling accurate fault diagnosis under imbalanced data conditions. Experimental results show that the proposed method effectively captures fault characteristic frequency variations consistent with actual conditions. The spectrum of the simulated signals reflects clear physical significance, providing a robust basis for understanding fault mechanisms and improving the reliability and precision of fault diagnosis. This work offers a novel solution for linking internal fault dynamics to external measurements for canned motor pumps, providing a practical potential for handling imbalanced data and advancing fault diagnosis in complex enclosed mechanical systems.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110181"},"PeriodicalIF":7.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738494","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

Surface quality in ultrasonic-electrolytic internal grinding of GCr15 steel

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI: 10.1016/j.ijmecsci.2025.110188

Hongyin Zhang, Feng Jiao, Xiaoxu Lian, Yuehan Zhao, Ying Niu, Jinglin Tong

{"title":"Surface quality in ultrasonic-electrolytic internal grinding of GCr15 steel","authors":"Hongyin Zhang, Feng Jiao, Xiaoxu Lian, Yuehan Zhao, Ying Niu, Jinglin Tong","doi":"10.1016/j.ijmecsci.2025.110188","DOIUrl":"10.1016/j.ijmecsci.2025.110188","url":null,"abstract":"<div><div>To tackle the issues of poor surface quality, grinding burn, microcrack and deformation in conventional grinding, in this paper, combined the merits of ultrasonic vibration and electrolytic grinding, the material removal characteristics of GCr15 steel in longitudinal torsional ultrasonic electrolytic internal grinding were revealed based on the kinematic analysis of single abrasive particle. Additionally, a theoretical analysis of the heights of material removed by electrolytic action and mechanical grinding was conducted. The single factor experiments were completed for conventional grinding (CG), longitudinal torsional ultrasonic grinding (LTUG), electrolytic grinding (EG) and longitudinal torsional ultrasonic electrolytic grinding (LTUEG). The results demonstrated the superiority of LTUEG processing through comparisons with CG, LTUG and EG. LTUEG shows significant advantages in reducing grinding force, improving surface roughness and quality, and achieving ideal microhardness and residual stress. The formation and removal mechanism of the passivation film were elucidated. The passivation film was primarily composed of iron oxides, hydroxides, and precipitates of the C element. Increasing the voltage helped to increase the thickness of the passive film and reduce the actual grinding depth; however, excessively high voltages could easily lead to residual passive film coverage and electrolytic burn phenomena. The influence of different processing parameters on surface quality was investigated. Within a certain range, increasing the ultrasonic amplitude, voltage, and grinding wheel speed, while decreasing the feed speed, had a beneficial effect on enhancing the surface quality. Therefore, LTUEG is an effective processing method to improve the quality of GCr15 steel.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110188"},"PeriodicalIF":7.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715062","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

Composition and layered co-continuous structure co-regulate shape memory properties

IF 7.1 1区工程技术

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI: 10.1016/j.ijmecsci.2025.110187

Feng Yang , Haofan He , Jiye Jia , Ping Wu , Pei Feng , Cijun Shuai

{"title":"Composition and layered co-continuous structure co-regulate shape memory properties","authors":"Feng Yang , Haofan He , Jiye Jia , Ping Wu , Pei Feng , Cijun Shuai","doi":"10.1016/j.ijmecsci.2025.110187","DOIUrl":"10.1016/j.ijmecsci.2025.110187","url":null,"abstract":"<div><div>4D printed shape memory implant is highly promising for the realization of minimally invasive, while challenged by the poor shape memory effect (SME) of commonly used biodegradable shape memory polymer (SMP) such as poly(L-lactic acid) (PLLA) and thermoplastic polyurethane (TPU). Herein, the shape memory bone scaffold was fabricated by laser powder bed fusion (LPBF) with layered co-continuous structures containing PLLA and TPU. And SME of the scaffold was ameliorated by regulating the material composition and constructing a special layered co-continuous structure for the first time. The layered co-continuous structure could avoid the impact of morphology on SME due to the immiscibility between PLLA and TPU, thus broadening the window of tuning the SME. As the ratio of PLLA and TPU decreased gradually, the shape fixity ratio (R<sub>f</sub>) decreased and the shape recovery ratio (R<sub>r</sub>) increased. This was attributed to the combination of changes in the ratio of \"switching segment and netpoint\" and the reverse stiffness effect between PLLA and TPU. Besides, due to the efficient stress transfer in the layered co-continuous structure, the R<sub>f</sub> and R<sub>r</sub> would be considerably changed only when the content threshold of the switching segment or netpoint was reached. A good SME was obtained when the ratio of TPU to PLLA was 2:1, with R<sub>f</sub> of 96.5 % and R<sub>r</sub> of 96.71 % compared to the pure PLLA. Additionally, the scaffold exhibited sufficient compressive strength and benign cytocompatibility. This study proposed a new and simple but effective strategy to prepare bone scaffold with excellent shape memory properties.</div></div>","PeriodicalId":56287,"journal":{"name":"International Journal of Mechanical Sciences","volume":"291 ","pages":"Article 110187"},"PeriodicalIF":7.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726281","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