首页 > 最新文献

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications最新文献

英文 中文
High strain rate response of ABS-M30i-based 3D printed, bio-inspired, bovine bone structure 基于 ABS-M30i 的 3D 打印生物启发牛骨结构的高应变率响应
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-04 DOI: 10.1177/14644207241244731
Ali Imran Ansari, Nazir Ahmad Sheikh, Navin Kumar
To investigate osteoporosis caused by aging and the dynamic behavior of male bovine trabecular bone, three age groups of male bovine trabecular bone were chosen, and micro-computed tomography (CT) analysis was performed to develop an image-based bio-inspired computer-aided design (CAD) model of the bone structure. Further experimental and computational studies were carried out to examine the rate-dependent behavior and compressive energy-absorbing capacity of the structure as a function of age. To evaluate this study, a micro-CT-based CAD model of the structure was 3D printed using ABS-M30i material and subjected to quasi-static compression (low strain rate) and high strain rate (split Hopkinson pressure bar) compression. The findings show that 3D-printed bovine structures have distinct high-rate dependence at strain rates greater than 430 s−1, as well as sensitivity to strain rate in terms of peak stress, plateau stress, and energy absorption capacity. Using rate-dependent properties, the Johnson–Cook damage plasticity model was used in computational analysis to explain the dynamic behavior of bone due to osteoporosis. Overall, there is good agreement between the numerical simulations and the experimental data, which was obtained by verifying and validating the model against the experimental results.
为了研究衰老引起的骨质疏松症和雄性牛小梁骨的动态行为,选择了三个年龄组的雄性牛小梁骨,并进行了显微计算机断层扫描(CT)分析,以建立基于图像的生物启发计算机辅助设计(CAD)骨结构模型。通过进一步的实验和计算研究,考察了该结构随年龄变化的速率依赖行为和压缩能量吸收能力。为了评估这项研究,使用 ABS-M30i 材料 3D 打印了基于微型 CT 的结构 CAD 模型,并对其进行了准静态压缩(低应变率)和高应变率(分裂霍普金森压力棒)压缩。研究结果表明,当应变速率大于 430 s-1 时,三维打印的牛体结构具有明显的高应变速率依赖性,并且在峰值应力、高原应力和能量吸收能力方面对应变速率具有敏感性。利用速率依赖性特性,计算分析中使用了约翰逊-库克损伤塑性模型来解释骨质疏松症导致的骨骼动态行为。总体而言,数值模拟与实验数据之间具有良好的一致性,这是在实验结果的基础上对模型进行验证和确认后得到的。
{"title":"High strain rate response of ABS-M30i-based 3D printed, bio-inspired, bovine bone structure","authors":"Ali Imran Ansari, Nazir Ahmad Sheikh, Navin Kumar","doi":"10.1177/14644207241244731","DOIUrl":"https://doi.org/10.1177/14644207241244731","url":null,"abstract":"To investigate osteoporosis caused by aging and the dynamic behavior of male bovine trabecular bone, three age groups of male bovine trabecular bone were chosen, and micro-computed tomography (CT) analysis was performed to develop an image-based bio-inspired computer-aided design (CAD) model of the bone structure. Further experimental and computational studies were carried out to examine the rate-dependent behavior and compressive energy-absorbing capacity of the structure as a function of age. To evaluate this study, a micro-CT-based CAD model of the structure was 3D printed using ABS-M30i material and subjected to quasi-static compression (low strain rate) and high strain rate (split Hopkinson pressure bar) compression. The findings show that 3D-printed bovine structures have distinct high-rate dependence at strain rates greater than 430 s<jats:sup>−1</jats:sup>, as well as sensitivity to strain rate in terms of peak stress, plateau stress, and energy absorption capacity. Using rate-dependent properties, the Johnson–Cook damage plasticity model was used in computational analysis to explain the dynamic behavior of bone due to osteoporosis. Overall, there is good agreement between the numerical simulations and the experimental data, which was obtained by verifying and validating the model against the experimental results.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"18 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Biomimetic design and fabrication of thermally induced radial gradient shape memory scaffolds using fused deposition modeling (FDM) for bone tissue engineering 利用熔融沉积建模技术(FDM)仿生设计和制造用于骨组织工程的热诱导径向梯度形状记忆支架
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-03 DOI: 10.1177/14644207241245335
Meltem Eryildiz
Bone defects pose a significant challenge, often exceeding natural healing capabilities. This study explores the potential of thermally induced radial gradient shape memory (RGSM) scaffolds for minimally invasive bone repair. Inspired by the natural porosity gradient of bone, these scaffolds feature a high-porosity inner zone that mimics cancellous bone and a low-porosity outer zone that resembles cortical bone. When the relationship between porosity and key properties was investigated, it was found that lower-porosity RGSM scaffolds exhibited higher compressive strength but experienced higher residual strain and lower shape recovery ratio compared to their higher-porosity counterparts. Despite this trade-off, the gradient design successfully mimicked the natural bone structure, potentially enhancing osseointegration and bone regeneration. These results demonstrate the feasibility of RGSM scaffolds for bone tissue engineering. This holds promise for advancing minimally invasive surgical techniques and improving the treatment of bone defects.
骨缺损是一项重大挑战,往往超出自然愈合能力。本研究探讨了热诱导径向梯度形状记忆(RGSM)支架在微创骨修复方面的潜力。受骨骼天然孔隙率梯度的启发,这些支架具有模仿松质骨的高孔隙率内区和类似皮质骨的低孔隙率外区。在研究孔隙率与关键特性之间的关系时发现,孔隙率较低的 RGSM 支架与孔隙率较高的支架相比,抗压强度更高,但残余应变更大,形状恢复比更低。尽管存在这种权衡,但梯度设计成功地模拟了天然骨结构,可能会促进骨结合和骨再生。这些结果证明了 RGSM 支架用于骨组织工程的可行性。这为推进微创手术技术和改善骨缺损治疗带来了希望。
{"title":"Biomimetic design and fabrication of thermally induced radial gradient shape memory scaffolds using fused deposition modeling (FDM) for bone tissue engineering","authors":"Meltem Eryildiz","doi":"10.1177/14644207241245335","DOIUrl":"https://doi.org/10.1177/14644207241245335","url":null,"abstract":"Bone defects pose a significant challenge, often exceeding natural healing capabilities. This study explores the potential of thermally induced radial gradient shape memory (RGSM) scaffolds for minimally invasive bone repair. Inspired by the natural porosity gradient of bone, these scaffolds feature a high-porosity inner zone that mimics cancellous bone and a low-porosity outer zone that resembles cortical bone. When the relationship between porosity and key properties was investigated, it was found that lower-porosity RGSM scaffolds exhibited higher compressive strength but experienced higher residual strain and lower shape recovery ratio compared to their higher-porosity counterparts. Despite this trade-off, the gradient design successfully mimicked the natural bone structure, potentially enhancing osseointegration and bone regeneration. These results demonstrate the feasibility of RGSM scaffolds for bone tissue engineering. This holds promise for advancing minimally invasive surgical techniques and improving the treatment of bone defects.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"71 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140576171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A sustainable and energy efficient approach for development of electrically conductive materials and their characterizations 开发导电材料及其表征的可持续和高能效方法
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-02 DOI: 10.1177/14644207241244600
Khalid Bashir, Dheeraj Gupta, Vivek Jain
In this study, composite castings of electrically conductive materials were prepared using electromagnetic energy of frequency 2.45 GHz. Three separate sets of castings were produced inside the domestic microwave applicator cavity, with reinforced compositions of up to 15% in steps of 5% for each composite cast (copper (Cu) + 5% molybdenum (Mo), Cu + 10% Mo, and Cu + 15% Mo). A microwave radiation exposure time of 12 min was required for the complete melting of pure copper powder. However, the addition of Mo reinforcement caused a reduction in exposure time to 11.33 min (min) for the Cu-15% Mo composite cast. The formation of different phases was revealed by the X-ray diffraction analysis of the cast samples. Only a 0.92% copper oxide phase was detected in the pure copper cast samples. The composite cast samples exhibited peaks corresponding to Cu64O, Cu6Mo5O18, and MoO2. Microstructure analysis demonstrated that the grains grew in an equiaxed manner with a uniform dispersion of the reinforcements. The maximum microhardness achieved is 99.2 ± 4.99 Hv for Cu + 15% Mo which is 1.66 times better than microwave-cast copper sample.
本研究利用频率为 2.45 GHz 的电磁能制备了导电材料复合铸件。在家用微波炉的炉腔内分别制备了三组铸件,每组铸件的强化成分最高为 15%,以 5%为单位(铜 (Cu) + 5%钼 (Mo)、铜 + 10%钼和铜 + 15%钼)。纯铜粉完全熔化需要 12 分钟的微波辐射时间。然而,添加 Mo 增强剂后,Cu-15% Mo 复合铸件的辐射时间缩短至 11.33 分钟。铸件样品的 X 射线衍射分析显示了不同相的形成。在纯铜铸件样品中只检测到 0.92% 的氧化铜相。复合铸件样品显示出对应于 Cu64O、Cu6Mo5O18 和 MoO2 的峰值。显微结构分析表明,晶粒以等轴的方式生长,增强体均匀分布。Cu + 15% Mo 的最大显微硬度为 99.2 ± 4.99 Hv,是微波铸造铜样品的 1.66 倍。
{"title":"A sustainable and energy efficient approach for development of electrically conductive materials and their characterizations","authors":"Khalid Bashir, Dheeraj Gupta, Vivek Jain","doi":"10.1177/14644207241244600","DOIUrl":"https://doi.org/10.1177/14644207241244600","url":null,"abstract":"In this study, composite castings of electrically conductive materials were prepared using electromagnetic energy of frequency 2.45 GHz. Three separate sets of castings were produced inside the domestic microwave applicator cavity, with reinforced compositions of up to 15% in steps of 5% for each composite cast (copper (Cu) + 5% molybdenum (Mo), Cu + 10% Mo, and Cu + 15% Mo). A microwave radiation exposure time of 12 min was required for the complete melting of pure copper powder. However, the addition of Mo reinforcement caused a reduction in exposure time to 11.33 min (min) for the Cu-15% Mo composite cast. The formation of different phases was revealed by the X-ray diffraction analysis of the cast samples. Only a 0.92% copper oxide phase was detected in the pure copper cast samples. The composite cast samples exhibited peaks corresponding to Cu<jats:sub>64</jats:sub>O, Cu<jats:sub>6</jats:sub>Mo<jats:sub>5</jats:sub>O<jats:sub>18</jats:sub>, and MoO<jats:sub>2</jats:sub>. Microstructure analysis demonstrated that the grains grew in an equiaxed manner with a uniform dispersion of the reinforcements. The maximum microhardness achieved is 99.2 ± 4.99 Hv for Cu + 15% Mo which is 1.66 times better than microwave-cast copper sample.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"58 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A review on the fused deposition modelling of fibre-reinforced polymer composites: Influence of process parameters, pre-processing and post processing techniques 纤维增强聚合物复合材料熔融沉积建模综述:工艺参数、预处理和后处理技术的影响
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-02 DOI: 10.1177/14644207241243298
C Naveen Kumar, Subramani Venkatesan
Additive manufacturing is one of the latest manufacturing techniques that has gained universal recognition due to its material conservation nature. Fused deposition modelling (FDM) is an additive manufacturing technique that employs material extrusion to build components layer by layer. Thermoplastic polymers are used in FDM, and the components created are anisotropic and porous. Composite materials are used to improve the quality of the components. This article reviews recent research focused on the enhancement of the mechanical performance of composites produced by FDM. The influence of process parameters, type of fibre reinforcement (short and continuous fibres), pre-processing, process modification and post-processing techniques is analysed. Short fibres improved the mechanical performance of components, irrespective of the polymer matrix. Short fibres offered dimensional stability to the components, besides improving mechanical performance. Continuous fibres produce components with superior mechanical properties than short fibre composites. Continuous fibre reinforcement is the most effective reinforcement for fabricating structural and functional components in FDM. The importance of pre-processing, process modification and post-processing techniques in improving the mechanical characteristics of the components is discussed. In addition, this review identifies the significant challenges and perspectives for the future development of FDM technology in fibre-reinforced composites.
增材制造是最新的制造技术之一,因其节约材料的特性而得到了普遍认可。熔融沉积模型(FDM)是一种快速成型制造技术,它采用材料挤压的方式逐层制造部件。FDM 使用热塑性聚合物,制造出的部件具有各向异性和多孔性。复合材料可用于提高组件的质量。本文回顾了近期关于提高 FDM 复合材料机械性能的研究。文章分析了工艺参数、纤维增强类型(短纤维和连续纤维)、预处理、工艺修改和后处理技术的影响。无论聚合物基体如何,短纤维都能改善部件的机械性能。短纤维除了能提高机械性能外,还能为部件提供尺寸稳定性。与短纤维复合材料相比,连续纤维生产的部件具有更优越的机械性能。连续纤维增强材料是在 FDM 中制造结构和功能部件的最有效增强材料。本综述讨论了预处理、工艺改性和后处理技术在改善部件机械特性方面的重要性。此外,本综述还指出了 FDM 技术在纤维增强复合材料领域的重大挑战和未来发展前景。
{"title":"A review on the fused deposition modelling of fibre-reinforced polymer composites: Influence of process parameters, pre-processing and post processing techniques","authors":"C Naveen Kumar, Subramani Venkatesan","doi":"10.1177/14644207241243298","DOIUrl":"https://doi.org/10.1177/14644207241243298","url":null,"abstract":"Additive manufacturing is one of the latest manufacturing techniques that has gained universal recognition due to its material conservation nature. Fused deposition modelling (FDM) is an additive manufacturing technique that employs material extrusion to build components layer by layer. Thermoplastic polymers are used in FDM, and the components created are anisotropic and porous. Composite materials are used to improve the quality of the components. This article reviews recent research focused on the enhancement of the mechanical performance of composites produced by FDM. The influence of process parameters, type of fibre reinforcement (short and continuous fibres), pre-processing, process modification and post-processing techniques is analysed. Short fibres improved the mechanical performance of components, irrespective of the polymer matrix. Short fibres offered dimensional stability to the components, besides improving mechanical performance. Continuous fibres produce components with superior mechanical properties than short fibre composites. Continuous fibre reinforcement is the most effective reinforcement for fabricating structural and functional components in FDM. The importance of pre-processing, process modification and post-processing techniques in improving the mechanical characteristics of the components is discussed. In addition, this review identifies the significant challenges and perspectives for the future development of FDM technology in fibre-reinforced composites.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"52 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Evolution of variable angle tow composite structures: Data analysis and relevance of the theme 变角牵引复合结构的演变:数据分析与主题相关性
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-02 DOI: 10.1177/14644207241240048
Maisa Milanez Ávila Dias Maciel, Sandro Amico, Rui Miranda Guedes, Volnei Tita
Variable angle tow composites were developed to increase stiffness in notched laminates. Scientific advancements in manufacturing and fiber path optimization have since improved variable angle tow composites. This study uses bibliometric analysis to track the evolution of variable angle tow composites in the literature. Bibliometric analysis is a useful tool for measuring paper contributions and accurately assessing performance, aiding authors in the research process. This article presents a co-occurrence map of keyword frequency in research papers. Furthermore, an experimental section highlights manufacturing defects found in variable angle tow composites produced by filament winding, showing that manufacturing real structures in variable angle tow composites poses a significant challenge. Lastly, the perspectives of variable angle tow composite applications are discussed.
开发变角丝束复合材料是为了提高缺口层压板的刚度。此后,制造和纤维路径优化方面的科学进步改进了变角丝束复合材料。本研究采用文献计量分析法跟踪文献中变角丝束复合材料的演变。文献计量分析是衡量论文贡献和准确评估绩效的有用工具,有助于作者开展研究工作。本文介绍了研究论文中关键词频率的共现图谱。此外,实验部分重点介绍了通过缠绕长丝生产变角丝束复合材料过程中发现的制造缺陷,表明用变角丝束复合材料制造实际结构是一项重大挑战。最后,讨论了变角丝束复合材料的应用前景。
{"title":"Evolution of variable angle tow composite structures: Data analysis and relevance of the theme","authors":"Maisa Milanez Ávila Dias Maciel, Sandro Amico, Rui Miranda Guedes, Volnei Tita","doi":"10.1177/14644207241240048","DOIUrl":"https://doi.org/10.1177/14644207241240048","url":null,"abstract":"Variable angle tow composites were developed to increase stiffness in notched laminates. Scientific advancements in manufacturing and fiber path optimization have since improved variable angle tow composites. This study uses bibliometric analysis to track the evolution of variable angle tow composites in the literature. Bibliometric analysis is a useful tool for measuring paper contributions and accurately assessing performance, aiding authors in the research process. This article presents a co-occurrence map of keyword frequency in research papers. Furthermore, an experimental section highlights manufacturing defects found in variable angle tow composites produced by filament winding, showing that manufacturing real structures in variable angle tow composites poses a significant challenge. Lastly, the perspectives of variable angle tow composite applications are discussed.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"21 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Homogenised strength criterion for natural fibre-reinforced composite 天然纤维增强复合材料的均质强度准则
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-04-01 DOI: 10.1177/14644207241242382
Himanshu Prajapati, Anurag Dixit, Abhishek Tevatia
A representative model for multilayer natural fibre composite (NFC) plates is introduced to investigate its homogenised strength criterion. A three-layer NFC plate model is used to analyse the local stress–strain characteristics in multi-layered NFC. Finite element analysis (FEA) is performed on the representative volume element (RVE) under various boundary conditions to investigate stress and strain at macroscopic and microscopic levels. The explicit assessment of homogenised strength requires calculating stress tensors and equivalent stresses to determine parameter values. The precise specification of homogenised strength requirements assists in comprehending the material's behaviour under various loading conditions, which affects composite application design and optimisation techniques. The study examined the effect of fibre orientation angles on NFC's mechanical behaviour. The results demonstrate that flax fibres have comparatively higher stress levels than coir fibres. This study improves the understanding of natural fibre laminate composites’ macroscopic and microscopic behaviours, that is, the material's response under different loadings. The definition of homogenised strength criterion on NFC improves their design evaluations.
介绍了多层天然纤维复合材料(NFC)板的代表性模型,以研究其均质强度准则。三层 NFC 板模型用于分析多层 NFC 的局部应力应变特性。在各种边界条件下对代表性体积元素(RVE)进行有限元分析,以研究宏观和微观层面的应力和应变。对均化强度的明确评估需要计算应力张量和等效应力,以确定参数值。均化强度要求的精确规范有助于理解材料在各种加载条件下的行为,从而影响复合材料的应用设计和优化技术。这项研究考察了纤维取向角对 NFC 机械性能的影响。结果表明,亚麻纤维的应力水平相对高于棕纤维。这项研究加深了人们对天然纤维层压复合材料宏观和微观行为的理解,即材料在不同载荷下的反应。对 NFC 均化强度标准的定义改进了对其设计的评估。
{"title":"Homogenised strength criterion for natural fibre-reinforced composite","authors":"Himanshu Prajapati, Anurag Dixit, Abhishek Tevatia","doi":"10.1177/14644207241242382","DOIUrl":"https://doi.org/10.1177/14644207241242382","url":null,"abstract":"A representative model for multilayer natural fibre composite (NFC) plates is introduced to investigate its homogenised strength criterion. A three-layer NFC plate model is used to analyse the local stress–strain characteristics in multi-layered NFC. Finite element analysis (FEA) is performed on the representative volume element (RVE) under various boundary conditions to investigate stress and strain at macroscopic and microscopic levels. The explicit assessment of homogenised strength requires calculating stress tensors and equivalent stresses to determine parameter values. The precise specification of homogenised strength requirements assists in comprehending the material's behaviour under various loading conditions, which affects composite application design and optimisation techniques. The study examined the effect of fibre orientation angles on NFC's mechanical behaviour. The results demonstrate that flax fibres have comparatively higher stress levels than coir fibres. This study improves the understanding of natural fibre laminate composites’ macroscopic and microscopic behaviours, that is, the material's response under different loadings. The definition of homogenised strength criterion on NFC improves their design evaluations.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"28 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Modelling and numerical analysis for rotatory friction welding of U75V steel rails U75V 钢轨旋转摩擦焊的建模和数值分析
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-03-29 DOI: 10.1177/14644207241242019
Han Zhang, Jiaqi Xie, Chang’an Li, Zhiming Zhu
This article presents a rotatory friction welding (RFW) method for U75V steel rail, aiming to mitigate challenges related to property discrepancies between the as-welded joints and the rail base metal (BM) and to narrow the heat-affected zone (HAZ) in conventional flash-butt welding (FBW) joints. A rotational intermediate plate is designed for rails with non-axisymmetric cross-sections, necessitating stationary during RFW. Advantages include achieving a relatively uniform welding heat input and maintaining the peak temperature of the contact interface near A1. To implement these concepts, a 2D finite element (FE) model for the RFW process of U75V rail steel rods was established and validated through experiments with identical process parameters. Microstructure predictions derived from continuous cooling transformation diagram confirm that ferrite microstructure is formed near A1 through rail steel RFW. Subsequently, a 3D FE model for intermediate plate RFW steel rails is developed to explore appropriate process parameter combinations. A suitable process parameters combination was identified, ensuring the peak temperature of the majority model contact interface does not exceed A1, resulting in a 76.7% reduction in HAZ (from ∼50 to 11.66 mm), and axial shortening of 8.10 mm, a significant decrease compared to the usual burn-off (30–40 mm) during FBW. These findings underscore the efficacy of this innovative welding solution and emphasize the significance of simulation technology in process optimization.
本文介绍了一种用于 U75V 钢轨的旋转摩擦焊(RFW)方法,旨在减轻焊接接头与钢轨母材(BM)之间的性能差异带来的挑战,并缩小传统闪光对接焊(FBW)接头的热影响区(HAZ)。旋转中间板专为横截面非轴对称的钢轨而设计,因此在射频焊接过程中必须保持静止。其优点包括实现相对均匀的焊接热输入,并将接触界面的峰值温度保持在 A1 附近。为了实现这些概念,我们建立了 U75V 轨道钢棒射频焊接工艺的二维有限元 (FE) 模型,并通过相同工艺参数的实验进行了验证。根据连续冷却转变图得出的微观结构预测结果证实,通过轨道钢 RFW,在 A1 附近形成了铁素体微观结构。随后,建立了中间板 RFW 钢轨的三维有限元模型,以探索合适的工艺参数组合。最终确定了一个合适的工艺参数组合,确保大多数模型接触界面的峰值温度不超过 A1,从而使 HAZ 减少 76.7%(从 50 毫米减少到 11.66 毫米),轴向缩短 8.10 毫米,与 FBW 过程中通常的烧损(30-40 毫米)相比显著减少。这些研究结果证明了这种创新焊接方案的有效性,并强调了模拟技术在工艺优化中的重要意义。
{"title":"Modelling and numerical analysis for rotatory friction welding of U75V steel rails","authors":"Han Zhang, Jiaqi Xie, Chang’an Li, Zhiming Zhu","doi":"10.1177/14644207241242019","DOIUrl":"https://doi.org/10.1177/14644207241242019","url":null,"abstract":"This article presents a rotatory friction welding (RFW) method for U75V steel rail, aiming to mitigate challenges related to property discrepancies between the as-welded joints and the rail base metal (BM) and to narrow the heat-affected zone (HAZ) in conventional flash-butt welding (FBW) joints. A rotational intermediate plate is designed for rails with non-axisymmetric cross-sections, necessitating stationary during RFW. Advantages include achieving a relatively uniform welding heat input and maintaining the peak temperature of the contact interface near A<jats:sub>1</jats:sub>. To implement these concepts, a 2D finite element (FE) model for the RFW process of U75V rail steel rods was established and validated through experiments with identical process parameters. Microstructure predictions derived from continuous cooling transformation diagram confirm that ferrite microstructure is formed near A<jats:sub>1</jats:sub> through rail steel RFW. Subsequently, a 3D FE model for intermediate plate RFW steel rails is developed to explore appropriate process parameter combinations. A suitable process parameters combination was identified, ensuring the peak temperature of the majority model contact interface does not exceed A<jats:sub>1</jats:sub>, resulting in a 76.7% reduction in HAZ (from ∼50 to 11.66 mm), and axial shortening of 8.10 mm, a significant decrease compared to the usual burn-off (30–40 mm) during FBW. These findings underscore the efficacy of this innovative welding solution and emphasize the significance of simulation technology in process optimization.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"49 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of Ag interlayer on the microstructural properties and nanocreep behavior of Ti6Al4V/AA7075 dissimilar laser weldments 银中间膜对 Ti6Al4V/AA7075 异种激光焊接件微观结构特性和纳米剥蚀行为的影响
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-03-28 DOI: 10.1177/14644207241243351
Asim Iltaf, Noureddine Barka, Shayan Dehghan
Creep failure poses a potential risk in dissimilar welded joints between aluminum and titanium alloys, potentially compromising the joint's integrity. This study utilizes laser beam welding (LBW) to achieve dissimilar joining of AA7075 and Ti6Al4V by incorporating an Ag interlayer. The role of Ag interlayer for dissimilar joining of AA7075 and Ti6Al4V alloys and its impact on the microstructure and nanocreep behavior of joints is examined. The findings showed that the use of Ag decreased the interaction of Ti/Al considerably with each other which led to a reduction in the formation of brittle intermetallic compounds. The nanohardness and atomic force microscopy (AFM) results indicated that the Ti6Al4V HAZ exhibited the highest hardness and least plastic deformation, owing to the formation of α′ martensite. The nanoindentation creep analysis revealed the highest stress exponent value in Ti6Al4V HAZ, pointing to a dislocation climb creep mechanism. Additionally, the results also suggested that the observed creep mechanism might be attributed to both diffusional creep and dislocation climb for other zones.
蠕变失效是铝合金和钛合金之间异种焊接接头的潜在风险,可能会破坏接头的完整性。本研究利用激光束焊接(LBW),通过加入银中间膜实现 AA7075 和 Ti6Al4V 的异种焊接。研究了AA7075和Ti6Al4V合金异种连接中银中间膜的作用及其对接头微观结构和纳米蠕变行为的影响。研究结果表明,Ag 的使用大大降低了 Ti/Al 之间的相互作用,从而减少了脆性金属间化合物的形成。纳米硬度和原子力显微镜(AFM)结果表明,由于形成了 α′ 马氏体,Ti6Al4V HAZ 的硬度最高,塑性变形最小。纳米压痕蠕变分析表明,Ti6Al4V HAZ 的应力指数值最高,表明存在位错攀升蠕变机制。此外,研究结果还表明,在其他区域观察到的蠕变机制可能同时归因于扩散蠕变和位错攀升。
{"title":"Effect of Ag interlayer on the microstructural properties and nanocreep behavior of Ti6Al4V/AA7075 dissimilar laser weldments","authors":"Asim Iltaf, Noureddine Barka, Shayan Dehghan","doi":"10.1177/14644207241243351","DOIUrl":"https://doi.org/10.1177/14644207241243351","url":null,"abstract":"Creep failure poses a potential risk in dissimilar welded joints between aluminum and titanium alloys, potentially compromising the joint's integrity. This study utilizes laser beam welding (LBW) to achieve dissimilar joining of AA7075 and Ti6Al4V by incorporating an Ag interlayer. The role of Ag interlayer for dissimilar joining of AA7075 and Ti6Al4V alloys and its impact on the microstructure and nanocreep behavior of joints is examined. The findings showed that the use of Ag decreased the interaction of Ti/Al considerably with each other which led to a reduction in the formation of brittle intermetallic compounds. The nanohardness and atomic force microscopy (AFM) results indicated that the Ti6Al4V HAZ exhibited the highest hardness and least plastic deformation, owing to the formation of α′ martensite. The nanoindentation creep analysis revealed the highest stress exponent value in Ti6Al4V HAZ, pointing to a dislocation climb creep mechanism. Additionally, the results also suggested that the observed creep mechanism might be attributed to both diffusional creep and dislocation climb for other zones.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"53 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Exploring bending behavior of curved sandwich panels with three-dimensional printed, functionally graded cores 探索带有三维打印功能分级芯材的曲面夹层板的弯曲行为
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-03-27 DOI: 10.1177/14644207241241211
Amirhamzeh Farajollahi, Mohsen Rostami, Mohammad Baharvand, Subhash Chandra, Pardeep Singh Bains
Sandwich structures have garnered significant attention due to their high strength-to-weight ratio in various industries, particularly aerospace. Meeting application demands requires optimizing mechanical properties such as bending stiffness, peak load, specific absorbed energy, and weight. This study presents a unique approach involving the design and manufacturing techniques of curved sandwich panels with functionally graded cores, aiming to achieve a comprehensive spectrum of bending properties. Curved structures have applications across diverse fields, including landing gear. The semi-circular core of the sandwich panel comprised three distinct regions defined by angles: Ф, Υ, and 90-Ф- Υ. These angles specified both the location and proportion of different honeycomb cells, including high, medium, and low-density cells. Any variations in these angles and their cell types resulted in a new density gradient. The manufactured sandwich structures consisted of polylactic acid cores printed by a fused deposition modeling printer, sandwiched between aluminum skins. Experimental tests and finite element analysis for three models showed strong agreement, with a maximum error of 14.45%. After the simulation was validated, it expanded to cover other configurations. Subsequently, mathematical models based on the aforementioned angles were calibrated using results extracted from the simulation step. This process led to achieving various structures characterized by a wide range of stiffness (ranging from 0.29 to 0.79 kN/mm), peak load (ranging from 1.73 to 4.77 kN), and specific absorbed energy values (ranging from 41.78 to 96.09 J/kg). The proposed methodology exhibits promise in engineering the design of these structures and their multi-objective optimization.
三明治结构因其在各行各业,尤其是航空航天领域的高强度重量比而备受关注。要满足应用需求,就必须优化机械性能,如弯曲刚度、峰值载荷、比吸收能量和重量。本研究提出了一种独特的方法,涉及具有功能分级芯材的曲面夹层板的设计和制造技术,旨在实现全面的弯曲性能。曲面结构的应用领域广泛,包括起落架。夹芯板的半圆形夹芯由三个不同的区域组成,分别由 Ф、Υ 和 90-Ф- Υ 角度定义。这些角度规定了不同蜂窝状单元的位置和比例,包括高密度、中密度和低密度单元。这些角度及其细胞类型的任何变化都会产生新的密度梯度。制造出的夹层结构由熔融沉积模型打印机打印的聚乳酸芯组成,夹在铝皮之间。三个模型的实验测试和有限元分析结果表明两者非常吻合,最大误差为 14.45%。模拟得到验证后,又扩展到其他配置。随后,利用从模拟步骤中提取的结果对基于上述角度的数学模型进行了校准。在此过程中,各种结构的刚度(从 0.29 到 0.79 kN/mm)、峰值载荷(从 1.73 到 4.77 kN)和比吸收能量值(从 41.78 到 96.09 J/kg)都得到了改善。所提出的方法有望用于这些结构的工程设计及其多目标优化。
{"title":"Exploring bending behavior of curved sandwich panels with three-dimensional printed, functionally graded cores","authors":"Amirhamzeh Farajollahi, Mohsen Rostami, Mohammad Baharvand, Subhash Chandra, Pardeep Singh Bains","doi":"10.1177/14644207241241211","DOIUrl":"https://doi.org/10.1177/14644207241241211","url":null,"abstract":"Sandwich structures have garnered significant attention due to their high strength-to-weight ratio in various industries, particularly aerospace. Meeting application demands requires optimizing mechanical properties such as bending stiffness, peak load, specific absorbed energy, and weight. This study presents a unique approach involving the design and manufacturing techniques of curved sandwich panels with functionally graded cores, aiming to achieve a comprehensive spectrum of bending properties. Curved structures have applications across diverse fields, including landing gear. The semi-circular core of the sandwich panel comprised three distinct regions defined by angles: Ф, Υ, and 90-Ф- Υ. These angles specified both the location and proportion of different honeycomb cells, including high, medium, and low-density cells. Any variations in these angles and their cell types resulted in a new density gradient. The manufactured sandwich structures consisted of polylactic acid cores printed by a fused deposition modeling printer, sandwiched between aluminum skins. Experimental tests and finite element analysis for three models showed strong agreement, with a maximum error of 14.45%. After the simulation was validated, it expanded to cover other configurations. Subsequently, mathematical models based on the aforementioned angles were calibrated using results extracted from the simulation step. This process led to achieving various structures characterized by a wide range of stiffness (ranging from 0.29 to 0.79 kN/mm), peak load (ranging from 1.73 to 4.77 kN), and specific absorbed energy values (ranging from 41.78 to 96.09 J/kg). The proposed methodology exhibits promise in engineering the design of these structures and their multi-objective optimization.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Metal matrix composites for sustainable products: A review on current development 用于可持续产品的金属基复合材料:当前发展综述
IF 2.4 4区 材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2024-03-26 DOI: 10.1177/14644207241238197
P K Gupta, Alok Kumar Trivedi, M K Gupta, Manish Dixit
In recent decades, with the increase in demand for lightweight and high-strength materials for engineering applications, metal matrix composites (MMCs) are found to be a better replacement for conventional materials owing to their excellent characteristics such as high strength-to-weight ratio, high strength and stiffness, high thermal conductivity and low coefficient of thermal expansion. MMCs have been used in various applications such as automobile parts, aerospace and aircraft parts, jet engines, satellites, missiles, military, heavy constructions, NASA space shuttle, bridges, biomedical applications (i.e., medical devices, implants and surgical instruments) and so on. Extensive research has been carried out on the performance of MMCs for the development of sustainable products, which motivated us to review the current development in the processing, properties and applications of these composites. This work presents a systematic review of the mechanical properties (tensile strength and modulus, flexural strength and modulus, impact strength and hardness) of MMCs. Further, it comprises the processing techniques, strengthening mechanism and applications of MMCs along with the recommendations for future work and challenges. The mechanical performances of MMCs are found to be highly influenced by the properties of reinforcement and matrices, interfacial bonding, dispersion of particles into matrix, shape and size of particles, percentage content of particles and processing techniques. This review study suggests that MMCs have great potential to efficiently fulfill the present and future demands.
近几十年来,随着工程应用领域对轻质高强材料需求的增加,金属基复合材料(MMC)因其高强度重量比、高强度和刚度、高导热性和低热膨胀系数等优良特性,被认为是传统材料的最佳替代品。MMC 已被广泛应用于汽车零部件、航空航天和飞机零部件、喷气发动机、卫星、导弹、军事、重型建筑、美国宇航局航天飞机、桥梁、生物医学应用(即医疗设备、植入物和手术器械)等领域。为了开发可持续产品,人们对 MMC 的性能进行了广泛的研究,这促使我们回顾这些复合材料在加工、性能和应用方面的发展现状。本研究系统回顾了多孔金属复合材料的机械性能(拉伸强度和模量、弯曲强度和模量、冲击强度和硬度)。此外,它还包括加工技术、强化机制和 MMC 的应用,以及对未来工作和挑战的建议。研究发现,增强材料和基体的性能、界面结合、颗粒在基体中的分散情况、颗粒的形状和尺寸、颗粒的百分比含量以及加工技术都会对间苯二甲酸甲酯的机械性能产生很大影响。本综述研究表明,间苯二甲酸甲酯具有巨大潜力,可有效满足当前和未来的需求。
{"title":"Metal matrix composites for sustainable products: A review on current development","authors":"P K Gupta, Alok Kumar Trivedi, M K Gupta, Manish Dixit","doi":"10.1177/14644207241238197","DOIUrl":"https://doi.org/10.1177/14644207241238197","url":null,"abstract":"In recent decades, with the increase in demand for lightweight and high-strength materials for engineering applications, metal matrix composites (MMCs) are found to be a better replacement for conventional materials owing to their excellent characteristics such as high strength-to-weight ratio, high strength and stiffness, high thermal conductivity and low coefficient of thermal expansion. MMCs have been used in various applications such as automobile parts, aerospace and aircraft parts, jet engines, satellites, missiles, military, heavy constructions, NASA space shuttle, bridges, biomedical applications (i.e., medical devices, implants and surgical instruments) and so on. Extensive research has been carried out on the performance of MMCs for the development of sustainable products, which motivated us to review the current development in the processing, properties and applications of these composites. This work presents a systematic review of the mechanical properties (tensile strength and modulus, flexural strength and modulus, impact strength and hardness) of MMCs. Further, it comprises the processing techniques, strengthening mechanism and applications of MMCs along with the recommendations for future work and challenges. The mechanical performances of MMCs are found to be highly influenced by the properties of reinforcement and matrices, interfacial bonding, dispersion of particles into matrix, shape and size of particles, percentage content of particles and processing techniques. This review study suggests that MMCs have great potential to efficiently fulfill the present and future demands.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"14 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140315017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1