今日更新:International Journal of Solids and Structures 2 篇,Journal of the Mechanics and Physics of Solids 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 4 篇
An enhanced simplified model for dynamic analysis of deployable Bennett linkages considering link cross-sectional size and contact
Zheng Yanfeng, Li Siyuan, Zhang Jingyao, Luo Yaozhi
doi:10.1016/j.ijsolstr.2023.112583
考虑到链节横截面尺寸和接触情况的可部署贝内特链节动态分析增强型简化模型
Deployable Bennett linkage has broad application prospects in engineering. Existing simplified models generally do not consider the link cross-sectional size and contact, and therefore, deviate from real-world Bennett linkages. This paper proposes an enhanced simplified model based on finite particle method (FPM) to consider link cross-sectional size and contact. Specifically, this model introduces virtual beams at the end cross-sections to consider the link cross-sectional size; furthermore, contacts between link surfaces, when Bennett linkage is fully folded or deployed, are considered by applying contact forces directly. The modeling methods for a single unit of Bennett linkage and an assembly are presented. The dynamic analysis method based on FPM is proposed for the enhanced simplified model, and the corresponding beam element, revolute hinge element, and contact element are derived. The dynamic responses of the unit of Bennett linkage are compared to those by the fine model to verify the proposed enhanced simplified model, and the influences of structural parameters are further investigated. The assembly of Bennett linkage is also analyzed to demonstrate the feasibility of the proposed method in the assembly of large-scale units. The numerical results demonstrate that the proposed method is effective and provides a promising approach for dynamic analysis of large-scale deployable Bennett linkages.
可部署贝内特连杆在工程领域具有广阔的应用前景。现有的简化模型一般不考虑连杆横截面尺寸和接触情况,因此与实际的贝内特连杆存在偏差。本文提出了一种基于有限粒子法(FPM)的增强简化模型,以考虑连杆横截面尺寸和接触情况。具体来说,该模型在末端横截面上引入了虚拟梁,以考虑连杆横截面尺寸;此外,当贝内特连杆完全折叠或展开时,连杆表面之间的接触是通过直接施加接触力来考虑的。本文介绍了单个贝内特连杆和组件的建模方法。针对增强型简化模型,提出了基于 FPM 的动态分析方法,并推导出相应的梁元素、旋转铰链元素和接触元素。将 Bennett 连杆单元的动态响应与精细模型的动态响应进行比较,以验证所提出的增强简化模型,并进一步研究了结构参数的影响。此外,还分析了贝内特连杆的装配情况,以证明所提方法在大型单元装配中的可行性。数值结果表明,所提出的方法是有效的,为大型可部署贝内特连杆的动态分析提供了一种可行的方法。
Multicell Thin-walled Method for Solid Multimaterial Beams
Ramírez-Luis Vicente, Hernández-Moreno Hilario, Susarrey-Huerta Orlando
doi:10.1016/j.ijsolstr.2023.112585
固体多材料梁的多孔薄壁法
In this paper we developed the Multicell Thin-walled Method for Solid Multimaterial Beams, which combines structural idealization used in aircraft components, thin-walled beam theory and homogenization techniques from composite materials applied to discrete models, to obtain the cross-section stress fields of solid beams made of multiple orthotropic and isotropic materials. This method idealizes a solid multimaterial cross-section as a multicell thin-walled section to accurately obtain complex stress fields while significantly reducing the solution time, as well as the computational cost, when compared to classical 3D finite element analyses. This method was implemented in a computer program and three examples were analyzed to validate results with the finite element method. Both methods show almost identical results in regions not affected by local disturbances.
在本文中,我们开发了用于实心多材料梁的多孔薄壁方法,该方法结合了飞机部件中使用的结构理想化、薄壁梁理论以及应用于离散模型的复合材料均质化技术,以获得由多种正交和各向同性材料构成的实心梁的横截面应力场。与传统的三维有限元分析相比,该方法将固体多材料横截面理想化为多单元薄壁截面,可精确获得复杂的应力场,同时大大减少求解时间和计算成本。该方法已在计算机程序中实施,并对三个实例进行了分析,以验证与有限元方法的结果。在不受局部扰动影响的区域,两种方法显示出几乎相同的结果。
A mechanically-derived contact model for adhesive elastic-perfectly plastic particles, Part I: Utilizing the method of dimensionality reduction
Zunker William, Kamrin Ken
doi:10.1016/j.jmps.2023.105492
粘性弹性完全可塑颗粒的机械接触模型,第一部分:利用降维方法
In this two part series (Zunker and Kamrin, 2024), we present a contact model able to capture the response of interacting adhesive elastic-perfectly plastic particles under a variety of loadings. In Part I, we focus on elastic through fully-plastic contact with and without adhesion. For these contact regimes the model is built upon the method of dimensionality reduction which allows the problem of a 3D axisymmetric contact to be mapped to a corresponding problem of a 1D rigid indenter penetrating a bed of independent Hookean springs. Plasticity is accounted for by continuously varying the 1D indenter profile subject to a constraint on the contact pressure. Unloading falls out naturally, and simply requires lifting the 1D indenter out of the springs and tracking the force. By accounting for the incompressible nature of this plastic deformation, the contact model is able to capture multi-neighbor dependent effects such as increased force and formation of new contacts. JKR type adhesion is recovered seamlessly within the method of dimensionality reduction by simply allowing the springs to ‘stick’ to the 1D indenter’s surface. Because of the mechanics-focused formulation of the contact model, only a few physical inputs describing the interacting particles are needed: particle radius, Young’s modulus, Poisson ratio, yield stress, and effective surface energy. The contact model is validated against finite element simulations and analytic theory—including Hertz’s contact law and the JKR theory of adhesion. These comparisons show that the proposed contact model is able to accurately capture plastic displacement, average contact pressure, contact area, and force as a function of displacement for contacts as well as particle volume within the elastic to fully-plastic regimes.
在本系列的两部分(Zunker 和 Kamrin,2024 年)中,我们介绍了一个接触模型,该模型能够捕捉到在各种载荷下相互作用的粘性弹性全塑颗粒的响应。在第一部分中,我们重点讨论了有粘性和无粘性的弹性接触和全塑接触。对于这些接触状态,模型建立在降维方法的基础上,该方法可将三维轴对称接触问题映射为一维刚性压头穿透独立胡克弹簧床的相应问题。通过连续改变一维压头的轮廓,并对接触压力进行约束,可对塑性进行解释。卸载自然产生,只需将一维压头抬出弹簧并跟踪力即可。通过考虑这种塑性变形的不可压缩性,接触模型能够捕捉多邻域效应,例如力的增加和新接触的形成。通过简单地让弹簧 "粘附 "在一维压头表面,JKR 型粘附可在降维方法中无缝恢复。由于接触模型是以力学为重点的表述,因此只需要几个描述相互作用颗粒的物理输入:颗粒半径、杨氏模量、泊松比、屈服应力和有效表面能。接触模型通过有限元模拟和分析理论(包括赫兹接触定律和 JKR 粘附理论)进行了验证。这些比较结果表明,所提出的接触模型能够准确捕捉到塑性位移、平均接触压力、接触面积和力与接触位移的函数关系,以及弹性至完全塑性状态下的颗粒体积。
Micromechanical properties and deformation behavior of the constituent phases in 3rd generation complex phase AHSS: In-situ neutron experiment and crystal plasticity simulation
Tran Minh Tien, Nguyen Xuan Minh, Kim Hyunki, Chae Hobyung, Woo Wanchuck, Lee Ho Won, Kim Dong-Kyu
doi:10.1016/j.ijplas.2023.103812
第三代复相 AHSS 中各组成相的微机械特性和变形行为:原位中子实验和晶体塑性模拟
This paper investigated the micromechanical properties and deformation behavior of the constituent phases in 3rd generation (GEN) complex phase advanced high-strength steel (AHSS). The hybrid method was a comprehensive combination of uniaxial tensile test with digital image correlation (DIC), electron backscatter diffraction (EBSD), in-situ neutron diffraction (NED) and crystal plasticity finite element method (CPFEM). Results reveal that the microstructure of 3rd GEN AHSS exhibits a complex phase of ferrite (46.2%), bainite (36.1%), martensite (9.4%) and austenite (8.3%), which would be promising microstructure in the development of new-generation complex phase AHSS. The significant findings are: 1) excellent ductility is obtained while high strength is preserved despite small martensite volume fraction, which can reduce the tendency of martensite cracking; 2) macroscopic stress-strain relationships and microscopic hardening properties of constituent phases are successfully determined, which are very important for predicting the overall performance of complex phase AHSS; 3) presence of bainite with high volume fraction plays a critical role in inducing plastic strain localization in ferrite, resulting in the heterogeneous stress/strain distribution. It is disclosed that pronounced strain localization is mostly initiated in ferrite grains while the deformation bands are mainly located in ferrite/bainite grain boundaries. Furthermore, strain partitioning between ferrite and bainite results in the high-stress concentration in bainite grains. As a result, these “hot zones”, i.e., ferrite grains, ferrite/bainite grain boundaries and bainite grains, experience high strain, strain gradient and stress, respectively, which can be a primary origin of ductile fracture initiation in the 3rd GEN complex phase AHSS. The findings reported in the present investigation would be of great interest in the development of new-generation complex phase automotive steels.
本文研究了第三代(GEN)复相先进高强度钢(AHSS)中各组成相的微观力学性能和变形行为。混合方法是单轴拉伸试验与数字图像相关(DIC)、电子反向散射衍射(EBSD)、原位中子衍射(NED)和晶体塑性有限元法(CPFEM)的综合。结果表明,第 3 代 AHSS 的微观结构呈现出铁素体(46.2%)、贝氏体(36.1%)、马氏体(9.4%)和奥氏体(8.3%)的复相,是开发新一代复相 AHSS 的理想微观结构。重要发现有1)尽管马氏体体积分数较小,但却获得了优异的延展性,同时保持了较高的强度,这可以降低马氏体开裂的倾向;2)成功确定了组成相的宏观应力应变关系和微观硬化特性,这对于预测复相 AHSS 的整体性能非常重要;3)高体积分数贝氏体的存在在诱导铁素体塑性应变局部化方面发挥了关键作用,导致了应力/应变的异质分布。研究表明,明显的应变局部化主要在铁素体晶粒中开始,而变形带主要位于铁素体/贝氏体晶界。此外,铁素体和贝氏体之间的应变分配导致高应力集中在贝氏体晶粒中。因此,这些 "热区",即铁素体晶粒、铁素体/贝氏体晶界和贝氏体晶粒,分别经历了高应变、应变梯度和应力,这可能是第三代 GEN 复相 AHSS 中韧性断裂发生的主要原因。本研究报告的发现对新一代复相汽车钢的开发具有重要意义。
Cold-Formed Stainless Steel Beams with Single Web Hole at Elevated Temperatures
Prabowo Andy, Huang Yuner, Young Ben
doi:10.1016/j.tws.2023.111321
高温下的单腹板孔冷弯不锈钢横梁
Steel structures are often used in buildings due to their advantage in weight-to-strength ratio. However, their structural capacity deteriorates in fire as the temperature of the structures rises. Investigation of cold-formed stainless steel (CFSS) structures at elevated temperatures is still limited, especially for rectangular hollow section (RHS) beams having a single web hole in the mid-span (perforated web). Therefore, a numerical investigation was conducted to evaluate the current design provisions to calculate the strength of such beams at elevated temperatures ranging from 22 - 900 °C. A total of 400 specimens of stainless steel grades austenitic (EN 1.4301) and lean duplex (EN 1.4162) were considered. The investigation used finite element analysis (FEA) to simulate the behaviour of RHS beams with perforated web under pure bending. The finite element (FE) model was validated against a series of experimental results available in literature. The comparison between flexural strengths obtained from FEA with design values calculated from the current design rules showed that the design rules are conservative. However, they are not always reliable and safe for RHS beams without and with a perforated web for the two material grades at elevated temperatures. In this study, only the design rules specified by Eurocode 3 are shown to be reliable and safe.
钢结构由于其重量强度比方面的优势,经常被用于建筑物中。然而,在火灾中,随着结构温度的升高,其结构承载能力也会下降。对高温下冷弯型钢(CFSS)结构的研究仍然有限,尤其是对跨中有单腹板孔(穿孔腹板)的矩形空心截面(RHS)梁。因此,我们开展了一项数值研究,以评估当前的设计规定,计算这类梁在 22 - 900 °C 高温下的强度。共考虑了 400 个奥氏体(EN 1.4301)和贫双相(EN 1.4162)不锈钢试样。研究使用有限元分析(FEA)模拟带穿孔腹板的 RHS 梁在纯弯曲下的行为。有限元 (FE) 模型与文献中的一系列实验结果进行了验证。将有限元分析得出的抗弯强度与根据现行设计规则计算得出的设计值进行比较后发现,设计规则是保守的。然而,在高温条件下,对于两种材料等级的无穿孔腹板和有穿孔腹板的 RHS 梁来说,设计规则并不总是可靠和安全的。在本研究中,只有 Eurocode 3 规定的设计规则才是可靠和安全的。
Sectional strength design of a double-skin truss-reinforced composite shear wall
Han Jianhong, Shu Ganping, Qin Ying, Zhou Guangen, Zhou Xiongliang
doi:10.1016/j.tws.2023.111377
双层桁架加固复合剪力墙的截面强度设计
The double-skin truss-reinforced composite shear wall is an innovative element which comprises two steel plates, core concrete, concrete-filled steel tubes (CFSTs), which act as boundary members, and steel truss connectors. Truss connectors decrease the out-of-plane deformation that affects the steel plates, and due to the resultant connection and constraint effects, the truss connectors enhance the bearing capacity of the wall. This paper briefly introduces the quasi-static test of five full-scale rectangular double-skin truss-reinforced composite shear wall specimens. The specimen exhibited shear compression failure with an aspect ratio of 2.0, and flexure shear failure occurred when the aspect ratio exceeded 2.0. Based on the analysis of actual stress state of the steel web and actual working performance of the infilled concrete, the shear strength and flexure strength design formulas of double-skin truss-reinforced composite shear wall were established. Comparison results with 26 specimens demonstrate that the design formulas exhibit remarkable accuracy, as most errors are within 20% and 25%, respectively. Which provide a preliminary sectional strength design proposal for the double-skin truss-reinforced composite shear wall.
双层桁架加固复合剪力墙是一种创新型构件,由两块钢板、核心混凝土、作为边界构件的混凝土填充钢管(CFST)以及钢桁架连接件组成。桁架连接件可减少影响钢板的平面外变形,由于由此产生的连接和约束效应,桁架连接件可提高剪力墙的承载能力。本文简要介绍了五个全尺寸矩形双层桁架加固复合剪力墙试件的准静力试验。试样在长宽比为 2.0 时出现剪切压缩破坏,当长宽比超过 2.0 时出现弯曲剪切破坏。在分析钢腹板实际应力状态和填充混凝土实际工作性能的基础上,建立了双层桁架加固复合剪力墙的抗剪强度和抗弯强度设计公式。与 26 个试件的比较结果表明,设计公式具有显著的准确性,误差大多分别在 20% 和 25% 以内。这为双层桁架加固复合剪力墙提供了初步的截面强度设计建议。
Enhancing performance of hybrid carbon/glass textile-reinforced composites: Theoretical prediction and experimental characterization
Shafiei Ehsan, Zhang Xin
doi:10.1016/j.tws.2023.111375
提高碳/玻璃纤维混合增强复合材料的性能:理论预测和实验表征
Multi-scale analysis is of great interest to calculate the final response of hybrid textile-reinforced carbon/glass epoxy (TRCG) composites based on micromechanical tests and geometrical properties. A novel multi-scale model and experiments are utilized to enhance the performance of TRCG composites. Experiments are conducted on TR glass/epoxy, carbon/epoxy, and 7 hybrid TRCGs. The model integrated viscoplastic-material and nonlinear-geometry properties and damage initiation-propagation mechanisms to address stress–strain curves that incline with experimental data with less than 11 % deviation. The microscopic scanning is utilized to study the fracture mechanisms and delaminated areas of specimens. The tensile curves and delaminated-area of TRCG composites are affected by the local glass/carbon mixed ratio and stacking arrangement. Alternative arrangement, H3:[G/C/G/C]S, provides better mechanical properties and a lower isotropy-mismatch effect and delaminated area compared to H1:[2G/2C]S, and H2:[2C/2G]S, and H4:[C/G/C/G]S. H5:[G/2C/G/C]S with the highest possible properties provides the lowest delaminated-area, because of bridging-glass layers to mitigate brittleness and primary failures of carbon, yet is low enough to restrict premature delamination. H6:[4G/2C/4G] and H7:[2G/2C/G]s with high isotropy-mismatch hustle premature failure and fail to deliver expected performance. The fracture mechanisms of TRCG composites are utilized to propose two 10-layer composites with alternative arrangements, which they are experimented afterwards to study the damage modes. It is concluded that H8:[G/C/G/C/G] laminate has the highest mechanical properties and energy absorption amongst TRCG composites. In which with highest integrity, the delaminated area is limited to the vicinity of fracture zone.
基于微机械测试和几何特性,多尺度分析对于计算混合织物增强碳/玻璃环氧树脂(TRCG)复合材料的最终响应非常重要。我们利用新型多尺度模型和实验来提高 TRCG 复合材料的性能。对 TR 玻璃/环氧树脂、碳/环氧树脂和 7 种混合 TRCG 进行了实验。该模型综合了粘塑性材料和非线性几何特性以及损伤引发-传播机制,以解决应力-应变曲线与实验数据的偏差小于 11% 的问题。利用显微镜扫描研究试样的断裂机制和分层区域。TRCG 复合材料的拉伸曲线和分层面积受局部玻璃/碳混合比和堆叠排列的影响。与 H1:[2G/2C]S、H2:[2C/2G]S 和 H4:[C/G/C/G]S 相比,H3:[G/C/G/C]S 的替代排列具有更好的机械性能、更低的各向同性失配效应和脱层面积。H5:[G/2C/G/C]S具有尽可能高的特性,可提供最小的分层面积,因为桥接玻璃层可减轻碳的脆性和初级失效,同时又足够低以限制过早分层。各向同性不匹配程度较高的 H6:[4G/2C/4G] 和 H7:[2G/2C/G] 会导致过早失效,达不到预期性能。利用 TRCG 复合材料的断裂机理,提出了两种不同排列的 10 层复合材料,并对它们进行了试验,以研究其破坏模式。结果表明,在 TRCG 复合材料中,H8:[G/C/G/C/G] 层板具有最高的机械性能和能量吸收能力。其中,H8:[G/C/G/C/G]具有最高的完整性,分层区域仅限于断裂带附近。
Metal-faced Sandwich composite panels: A Review
Singh Prabhjot, Sheikh Javed, Behera B K
doi:10.1016/j.tws.2023.111376
金属面三明治复合板:综述
This review paper discusses the challenges in improving the mechanical and structural performance of metal-faced sandwich composite panels while reducing weight and cost. It focuses on the core and facesheet structural trends of metal-faced sandwich panels, highlighting innovative design concepts and mechanical performance with respect to failure modes. The paper categorizes recent core geometries used in metal-faced sandwich structures into three types: cellular foam cores, two-dimensional periodic cores, and three-dimensional periodic cores, each with unique characteristics and advantages. The performance of metal sandwich panels with different core structures in response to various mechanical tests is also summarized, including high and low-velocity impact, flexural, and blast and fire resistance. The review emphasizes that the core geometry, facesheet thickness, and core-face interfacial bonding of sandwich composites play a critical role in determining their structural performance and potential applications. Overall, this review paper provides valuable insights into the challenges of improving the mechanical and structural performance of metal-faced sandwich composite panels and highlights the importance of innovative design concepts for achieving optimal performance.
本综述论文讨论了在减轻重量和降低成本的同时提高金属面夹芯复合板的机械和结构性能所面临的挑战。论文重点讨论了金属面夹芯复合板的芯材和面板结构发展趋势,突出强调了创新设计理念和失效模式方面的机械性能。论文将最近用于金属面夹层结构的芯材几何形状分为三种类型:蜂窝泡沫芯材、二维周期芯材和三维周期芯材,每种芯材都具有独特的特点和优势。此外,还总结了采用不同芯材结构的金属夹芯板在各种力学测试中的性能,包括高速和低速冲击、抗弯、抗爆和防火性能。综述强调,夹芯复合材料的芯材几何形状、面板厚度和芯面界面粘接在决定其结构性能和潜在应用方面起着至关重要的作用。总之,这篇综述论文就改善金属面夹芯复合材料板的机械和结构性能所面临的挑战提供了宝贵的见解,并强调了创新设计理念对实现最佳性能的重要性。