首页 > 最新文献

International Journal of Solids and Structures最新文献

英文 中文
Effect of interface type on deformation mechanisms of γ-TiAl alloy under different temperatures and strain rates by molecular dynamics simulation 分子动力学模拟不同温度和应变速率下界面类型对 γ-TiAl 合金变形机制的影响
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-28 DOI: 10.1016/j.ijsolstr.2024.113051

Crystalline interface plays a significant role in strengthening lamellar γ-TiAl alloys through reconciling the strength and ductility. Herein, the effects of temperature and strain rate on the tensile deformation of three lamellar γ-TiAl interface models are investigated by molecular dynamics simulations. The three interfaces, pseudo twin (PT), rotational boundary (RB), and true twin (TT), exhibit different tensile responses due to the different interface effects: TT interface only acts as a barrier of dislocation traversing to facilitate crack extension; PT interface acts as both dislocation barrier and emission source and has a stronger release of strain energy than TT interface, retarding the crack extension; RB interface can retard and resist crack extension due to the blunting and deflection of the crack tip and the best interface geometry compatibility. The defect evolution indicates that the elevated temperature suppresses dislocation propagation at low strain rate, while the high strain rate causes small lamellar stacking faults and slit-shaped holes along tensile direction at low temperature. In addition, the dual conditions of high strain rate and low temperature induce the phase transition from FCC to BCC and then BCC to HCP. These findings provide a specific insight to understand the atomistic mechanism of interface-mediated deformation.

晶体界面通过协调强度和延展性在强化片状γ-TiAl合金方面发挥着重要作用。本文通过分子动力学模拟研究了温度和应变速率对三种片状γ-TiAl界面模型拉伸变形的影响。由于界面效应不同,伪孪晶(PT)、旋转边界(RB)和真孪晶(TT)这三种界面表现出不同的拉伸响应:TT 界面仅作为位错穿越的屏障,促进裂纹扩展;PT 界面既是位错屏障又是发射源,比 TT 界面有更强的应变能释放,延缓裂纹扩展;RB 界面由于裂纹尖端的钝化和偏转以及最佳的界面几何兼容性,可以延缓和抵抗裂纹扩展。缺陷演化表明,温度升高抑制了低应变速率下的位错扩展,而高应变速率则会在低温下沿拉伸方向产生小的片状堆叠断层和狭缝形孔。此外,高应变率和低温的双重条件诱导了从 FCC 到 BCC,再从 BCC 到 HCP 的相变。这些发现为理解界面介导变形的原子机制提供了具体的见解。
{"title":"Effect of interface type on deformation mechanisms of γ-TiAl alloy under different temperatures and strain rates by molecular dynamics simulation","authors":"","doi":"10.1016/j.ijsolstr.2024.113051","DOIUrl":"10.1016/j.ijsolstr.2024.113051","url":null,"abstract":"<div><p>Crystalline interface plays a significant role in strengthening lamellar γ-TiAl alloys through reconciling the strength and ductility. Herein, the effects of temperature and strain rate on the tensile deformation of three lamellar γ-TiAl interface models are investigated by molecular dynamics simulations. The three interfaces, pseudo twin (PT), rotational boundary (RB), and true twin (TT), exhibit different tensile responses due to the different interface effects: TT interface only acts as a barrier of dislocation traversing to facilitate crack extension; PT interface acts as both dislocation barrier and emission source and has a stronger release of strain energy than TT interface, retarding the crack extension; RB interface can retard and resist crack extension due to the blunting and deflection of the crack tip and the best interface geometry compatibility. The defect evolution indicates that the elevated temperature suppresses dislocation propagation at low strain rate, while the high strain rate causes small lamellar stacking faults and slit-shaped holes along tensile direction at low temperature. In addition, the dual conditions of high strain rate and low temperature induce the phase transition from FCC to BCC and then BCC to HCP. These findings provide a specific insight to understand the atomistic mechanism of interface-mediated deformation.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142086782","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
Simulating loading–unloading hysteretic behaviors of nematic-genesis polydomain nematic elastomers 模拟向列-生成多域向列弹性体的加载-卸载滞后行为
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-24 DOI: 10.1016/j.ijsolstr.2024.113039

Nematic elastomers (NEs) are lightly cross-linked elastomers with nematic mesogens integrated in their polymer networks. Combination of large deformation capability with nematic-isotropic phase transition enables NEs to be the most promising soft materials for impact attenuation, actuation and soft robotics. In this paper, we focus on nematic-genesis polydomain NEs (N-PNEs) where mesogens are cross-linked at nematic states. N-PNEs are capable of absorbing and dissipating energy and easy to synthesize. We present a Voronoi diagram-based finite element model for specimen-scale N-PNEs, and investigate the cyclic tensile and compressive behaviors of N-PNEs at different strain rates. Our simulations reveal a smooth polydomain-monodomain transition during loading, accompanied by a full recovery of polydomain texture after the load is removed, indicating a memory effect of initial disordered mesogen alignment. The predicted behaviors align well with experimental observations, which validates our model. Furthermore, we assess the energy absorption and dissipation capabilities of N-PNEs compared to monodomain NEs, identifying conditions where N-PNEs exhibit superior performance. This study not only enhances our understanding of polydomain-monodomain transitions in N-PNEs, but also lays the groundwork for the development of N-PNE-based energy absorbers.

向列弹性体(NE)是一种轻度交联的弹性体,其聚合物网络中集成了向列介质。向列各向异性相变与大变形能力相结合,使 NE 成为最有前途的冲击衰减、驱动和软机器人软材料。在本文中,我们将重点研究介质在向列状态下交联的向列生成多域 NE(N-PNE)。N-PNEs 能够吸收和耗散能量,并且易于合成。我们提出了一种基于 Voronoi 图的试样尺度 N-PNE 有限元模型,并研究了 N-PNE 在不同应变速率下的循环拉伸和压缩行为。我们的模拟结果表明,在加载过程中,多域与单域之间会发生平滑过渡,而在卸载后,多域纹理会完全恢复,这表明初始无序介质排列会产生记忆效应。预测的行为与实验观察结果非常吻合,这验证了我们的模型。此外,我们还评估了 N-PNE 与单域 NE 相比的能量吸收和耗散能力,确定了 N-PNE 在哪些条件下表现出更优越的性能。这项研究不仅加深了我们对 N-PNE 中多域-单域转换的理解,还为开发基于 N-PNE 的能量吸收器奠定了基础。
{"title":"Simulating loading–unloading hysteretic behaviors of nematic-genesis polydomain nematic elastomers","authors":"","doi":"10.1016/j.ijsolstr.2024.113039","DOIUrl":"10.1016/j.ijsolstr.2024.113039","url":null,"abstract":"<div><p>Nematic elastomers (NEs) are lightly cross-linked elastomers with nematic mesogens integrated in their polymer networks. Combination of large deformation capability with nematic-isotropic phase transition enables NEs to be the most promising soft materials for impact attenuation, actuation and soft robotics. In this paper, we focus on nematic-genesis polydomain NEs (N-PNEs) where mesogens are cross-linked at nematic states. N-PNEs are capable of absorbing and dissipating energy and easy to synthesize. We present a Voronoi diagram-based finite element model for specimen-scale N-PNEs, and investigate the cyclic tensile and compressive behaviors of N-PNEs at different strain rates. Our simulations reveal a smooth polydomain-monodomain transition during loading, accompanied by a full recovery of polydomain texture after the load is removed, indicating a memory effect of initial disordered mesogen alignment. The predicted behaviors align well with experimental observations, which validates our model. Furthermore, we assess the energy absorption and dissipation capabilities of N-PNEs compared to monodomain NEs, identifying conditions where N-PNEs exhibit superior performance. This study not only enhances our understanding of polydomain-monodomain transitions in N-PNEs, but also lays the groundwork for the development of N-PNE-based energy absorbers.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097173","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
Multiscale modeling of diffuse damage and localized cracking in quasi-brittle materials under compression with a quadratic friction law 准脆性材料在二次摩擦律压缩条件下的弥散损伤和局部开裂的多尺度建模
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-22 DOI: 10.1016/j.ijsolstr.2024.113038

The diffuse damage and localized cracking of quasi-brittle materials (i.e., rocks and concretes) under compression can be delineated by a matrix-microcrack system, wherein a solid matrix phase is weakened by a large number of randomly oriented and distributed microcracks, and the macroscopic cracking is formed by a progressive evolution of microcracks. Several homogenization-based multiscale models have been proposed to describe this matrix-microcrack system, but most of them are based on a linear friction law on the microcrack surface, rendering a linear strength criterion. In this paper, we propose a new quadratic friction law within the local multiscale friction-damage (LMFD) model to capture the plastic distortion due to frictional sliding along the rough microcrack surface. Following that, a macroscopic Ottosen-type nonlinear strength criterion is rationally derived with up-scaling friction-damage coupling analysis. An enhanced semi-implicit return mapping (ESRM) algorithm with a substepping scheme is then developed to integrate the complex nonlinear constitutive model. The performance of LMFD model is evaluated compared to a wide range of experimental data on plain concretes, and the robustness of ESRM algorithm is assessed through a series of numerical tests. Subsequently, to effectively describe the localized cracking process, a regularization scheme is proposed by combining the phase-field model with the established LMFD model, and the discretization independent crack localization is numerically verified.

准脆性材料(如岩石和混凝土)在压缩条件下的弥散破坏和局部开裂可以用基体-微裂缝体系来描述,其中固体基体相被大量随机定向分布的微裂缝削弱,宏观裂缝由微裂缝的逐渐演化形成。为描述这种基体-微裂缝体系,已经提出了几种基于均质化的多尺度模型,但大多数都是基于微裂缝表面的线性摩擦定律,从而得出线性强度准则。在本文中,我们在局部多尺度摩擦损伤(LMFD)模型中提出了一种新的二次摩擦定律,以捕捉沿粗糙微裂纹表面摩擦滑动引起的塑性变形。随后,通过放大摩擦-损伤耦合分析,合理推导出宏观奥特森型非线性强度准则。然后,开发了一种带有子步进方案的增强型半隐式返回映射(ESRM)算法,用于整合复杂的非线性构成模型。将 LMFD 模型的性能与素混凝土的大量实验数据进行了比较评估,并通过一系列数值测试评估了 ESRM 算法的稳健性。随后,为了有效描述局部开裂过程,通过将相场模型与已建立的 LMFD 模型相结合,提出了一种正则化方案,并对离散化独立裂缝局部化进行了数值验证。
{"title":"Multiscale modeling of diffuse damage and localized cracking in quasi-brittle materials under compression with a quadratic friction law","authors":"","doi":"10.1016/j.ijsolstr.2024.113038","DOIUrl":"10.1016/j.ijsolstr.2024.113038","url":null,"abstract":"<div><p>The diffuse damage and localized cracking of quasi-brittle materials (<em>i.e.</em>, rocks and concretes) under compression can be delineated by a matrix-microcrack system, wherein a solid matrix phase is weakened by a large number of randomly oriented and distributed microcracks, and the macroscopic cracking is formed by a progressive evolution of microcracks. Several homogenization-based multiscale models have been proposed to describe this matrix-microcrack system, but most of them are based on a linear friction law on the microcrack surface, rendering a linear strength criterion. In this paper, we propose a new quadratic friction law within the local multiscale friction-damage (LMFD) model to capture the plastic distortion due to frictional sliding along the rough microcrack surface. Following that, a macroscopic Ottosen-type nonlinear strength criterion is rationally derived with up-scaling friction-damage coupling analysis. An enhanced semi-implicit return mapping (ESRM) algorithm with a substepping scheme is then developed to integrate the complex nonlinear constitutive model. The performance of LMFD model is evaluated compared to a wide range of experimental data on plain concretes, and the robustness of ESRM algorithm is assessed through a series of numerical tests. Subsequently, to effectively describe the localized cracking process, a regularization scheme is proposed by combining the phase-field model with the established LMFD model, and the discretization independent crack localization is numerically verified.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020768324003974/pdfft?md5=1b769b0bdaf457b7828d0aefcc676d14&pid=1-s2.0-S0020768324003974-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097172","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
Theoretical and numerical analysis on buckling instability in a thin film sandwiched between two finite-thickness substrates under in-plane compression 平面压缩条件下夹在两个有限厚度基底之间的薄膜屈曲不稳定性的理论和数值分析
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-22 DOI: 10.1016/j.ijsolstr.2024.113037

Capturing the buckling instability mechanics of multi-layered film/substrate structures is essential for providing theoretical guidelines for designing flexible electronics (e.g., stretchable interconnects and strain-limiting structures) and understanding the morphogenesis in biology and geology. Previous buckling models of tri-layer substrate/film/substrate structures usually assumed infinite substrate thickness and incomplete forms of interfacial shear stress, failing to distinguish between local wrinkling and global buckling. In this work, we extend our previous model (Yuan et al., 2023) by accounting for both finite substrate thickness and a complete form of interfacial shear stress, without assuming uniform membrane strain in the film, to study the buckling instability of tri-layer structures. The local wrinkling versus global buckling is distinguished through energy analysis, yielding phase diagrams for a wide range of geometric parameters and material properties. The effects of finite substrate thickness and moduli on the critical compressive strain and wavelength for the onset of local wrinkling are thoroughly investigated. The high accuracy of current model is demonstrated by the excellent agreement between analytical predictions and finite element analysis. This study provides new insights into the stability analysis of substrate/film/substrate systems, and will aid in the design of flexible electronics.

捕捉多层薄膜/基底结构的屈曲不稳定性力学,对于提供设计柔性电子器件(如可拉伸互连器件和应变限制结构)的理论指导以及理解生物学和地质学中的形态发生至关重要。以往的三层基板/薄膜/衬底结构屈曲模型通常假设基板厚度无限大,界面剪应力形式不完整,无法区分局部起皱和整体屈曲。在这项工作中,我们扩展了之前的模型(Yuan 等人,2023 年),同时考虑了有限的基底厚度和完整形式的界面剪应力,而没有假设薄膜中的膜应变是均匀的,从而研究了三层结构的屈曲不稳定性。通过能量分析区分了局部起皱和整体屈曲,得出了多种几何参数和材料特性的相图。深入研究了有限基材厚度和模量对局部起皱临界压缩应变和波长的影响。分析预测与有限元分析之间的出色一致性证明了当前模型的高准确性。这项研究为基底/薄膜/基底系统的稳定性分析提供了新的见解,并将有助于柔性电子产品的设计。
{"title":"Theoretical and numerical analysis on buckling instability in a thin film sandwiched between two finite-thickness substrates under in-plane compression","authors":"","doi":"10.1016/j.ijsolstr.2024.113037","DOIUrl":"10.1016/j.ijsolstr.2024.113037","url":null,"abstract":"<div><p>Capturing the buckling instability mechanics of multi-layered film/substrate structures is essential for providing theoretical guidelines for designing flexible electronics (e.g., stretchable interconnects and strain-limiting structures) and understanding the morphogenesis in biology and geology. Previous buckling models of tri-layer substrate/film/substrate structures usually assumed infinite substrate thickness and incomplete forms of interfacial shear stress, failing to distinguish between local wrinkling and global buckling. In this work, we extend our previous model (<span><span>Yuan et al., 2023</span></span>) by accounting for both finite substrate thickness and a complete form of interfacial shear stress, without assuming uniform membrane strain in the film, to study the buckling instability of tri-layer structures. The local wrinkling versus global buckling is distinguished through energy analysis, yielding phase diagrams for a wide range of geometric parameters and material properties. The effects of finite substrate thickness and moduli on the critical compressive strain and wavelength for the onset of local wrinkling are thoroughly investigated. The high accuracy of current model is demonstrated by the excellent agreement between analytical predictions and finite element analysis. This study provides new insights into the stability analysis of substrate/film/substrate systems, and will aid in the design of flexible electronics.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142075894","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
Microscopic instabilities in single crystal matrix composites 单晶基复合材料的微观不稳定性
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-22 DOI: 10.1016/j.ijsolstr.2024.113035

A finite strain micromechanical analysis is presented for the prediction of the loss of microscopic stability of a class of metal matrix composites that are subjected to axial compressive loading and undergoing large deformations. The metallic constituent behavior is modeled by the single crystal anisotropic plasticity theory in which, due to the resolved shear stresses, plastic deformations occur along certain pre-defined slip planes. Thus, this incremental plasticity theory is capable of providing the effect of the applied axial loading on the induced shear stresses which dominate the microbuckling. The composites are assumed to possess slight imperfections at the interfaces, and in order to satisfy the interfacial conditions, a perturbation expansion is employed which yields zero and first order micromechanical analysis problems. The zero order problem corresponds to the micromechanical modeling of the composite with no imperfections, whereas the solution of the first order problem is utilized to obtain the critical stresses and deformations at which bifurcation buckling occurs. Both problems are solved by employing the finite strain high-fidelity generalized method of cells (HFGMC) micromechanics. Applications are given for various types of single crystal matrix composites including layered, particulate, continuous and short fiber composites. Finally, a comparison between the compressive strengths of a standard metal matrix boron/aluminum and SiC/single crystal composites is presented and discussed.

本文介绍了一种有限应变微观力学分析方法,用于预测一类金属基复合材料在承受轴向压缩载荷和大变形时微观稳定性的丧失。金属成分的行为由单晶体各向异性塑性理论建模,在该理论中,由于剪应力的解析,塑性变形沿着某些预定义的滑移平面发生。因此,这种增量塑性理论能够提供外加轴向载荷对主导微屈曲的诱导剪应力的影响。假定复合材料的界面有轻微缺陷,为了满足界面条件,采用了扰动扩展,从而产生零阶和一阶微观力学分析问题。零阶问题对应于无缺陷复合材料的微观力学模型,而一阶问题的求解则用于获得发生分叉屈曲的临界应力和变形。这两个问题都是通过采用有限应变高保真广义单元法(HFGMC)微观力学来解决的。该方法适用于各种类型的单晶基复合材料,包括层状、颗粒状、连续和短纤维复合材料。最后,介绍并讨论了标准金属基硼/铝复合材料与碳化硅/单晶复合材料的抗压强度比较。
{"title":"Microscopic instabilities in single crystal matrix composites","authors":"","doi":"10.1016/j.ijsolstr.2024.113035","DOIUrl":"10.1016/j.ijsolstr.2024.113035","url":null,"abstract":"<div><p>A finite strain micromechanical analysis is presented for the prediction of the loss of microscopic stability of a class of metal matrix composites that are subjected to axial compressive loading and undergoing large deformations. The metallic constituent behavior is modeled by the single crystal anisotropic plasticity theory in which, due to the resolved shear stresses, plastic deformations occur along certain pre-defined slip planes. Thus, this incremental plasticity theory is capable of providing the effect of the applied axial loading on the induced shear stresses which dominate the microbuckling. The composites are assumed to possess slight imperfections at the interfaces, and in order to satisfy the interfacial conditions, a perturbation expansion is employed which yields zero and first order micromechanical analysis problems. The zero order problem corresponds to the micromechanical modeling of the composite with no imperfections, whereas the solution of the first order problem is utilized to obtain the critical stresses and deformations at which bifurcation buckling occurs. Both problems are solved by employing the finite strain high-fidelity generalized method of cells (HFGMC) micromechanics. Applications are given for various types of single crystal matrix composites including layered, particulate, continuous and short fiber composites. Finally, a comparison between the compressive strengths of a standard metal matrix boron/aluminum and SiC/single crystal composites is presented and discussed.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050175","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
New numerical resolution of the elastic quarter-space, eighth-space and finite-length-space contact problems 弹性四分之一空间、八分之一空间和有限长度空间接触问题的新数值解决方案
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-22 DOI: 10.1016/j.ijsolstr.2024.113031

In this paper, a new algorithm to solve the elastic quarter-space, the eighth-space and the finite-length-space contact problems is proposed. This corresponds to an extension of the Hertz theory. The theoretical foundations of such a problem are limited, due to the presence of displacements at the free edges- or stresses at the virtual edges — resulting to complex boundary conditions. The new approach presented here is 3D and based on Guilbault’s ingenious fast correction method. In this approach, the edge effects are taken into account by introducing two corrective factors ψ1, ψ2 respectively on the (Ox) and (Oz) axes to replace the mirror pressure iterative process of Hetenyi. The exact numerical values of these two correction factors are derived analytically. The results show that the free edge can substantially increase locally the contact pressure and therefore the stresses and displacement fields if close to the contact area. So the pressure field and the contact zone present an asymmetry which is more pronounced as the free edge is getting closer. This study is carried out on spaces with one, two and four free edges which will be respectively called: quarter-space, eighth-space and finite-length-space. A validation is performed using a Finite Element Method (FEM) analysis. A parametric study is also performed to exhibit the differences with the Hertz solution, including in the situation where one expects the truncation of the contact area when the free edge is virtually located within the Hertz contact area.

本文提出了一种解决弹性四分之一空间、八分之一空间和有限长度空间接触问题的新算法。这相当于赫兹理论的扩展。由于自由边缘存在位移或虚拟边缘存在应力,导致边界条件复杂,因此此类问题的理论基础有限。本文介绍的新方法是三维方法,基于 Guilbault 独创的快速修正方法。在这种方法中,通过在(Ox)轴和(Oz)轴上分别引入两个校正因子ψ1、ψ2,将边缘效应考虑在内,以取代赫特尼的镜面压力迭代过程。这两个校正因子的精确数值是通过分析得出的。结果表明,如果自由边缘靠近接触区域,会大大增加局部接触压力,从而增加应力场和位移场。因此,压力场和接触区呈现出不对称的现象,当自由边缘越来越靠近时,这种不对称现象更加明显。这项研究针对的是有一个、两个和四个自由边缘的空间,分别称为四分之一空间、八分之一空间和有限长度空间。使用有限元法(FEM)分析进行验证。还进行了参数研究,以显示与赫兹解法的不同之处,包括当自由边缘实际上位于赫兹接触区域内时,预计接触区域会被截断的情况。
{"title":"New numerical resolution of the elastic quarter-space, eighth-space and finite-length-space contact problems","authors":"","doi":"10.1016/j.ijsolstr.2024.113031","DOIUrl":"10.1016/j.ijsolstr.2024.113031","url":null,"abstract":"<div><p>In this paper, a new algorithm to solve the elastic quarter-space, the eighth-space and the finite-length-space contact problems is proposed. This corresponds to an extension of the Hertz theory. The theoretical foundations of such a problem are limited, due to the presence of displacements at the free edges- or stresses at the virtual edges — resulting to complex boundary conditions. The new approach presented here is 3D and based on Guilbault’s ingenious fast correction method. In this approach, the edge effects are taken into account by introducing two corrective factors <span><math><msub><mrow><mi>ψ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>ψ</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> respectively on the <span><math><mrow><mo>(</mo><mi>O</mi><mi>x</mi><mo>)</mo></mrow></math></span> and <span><math><mrow><mo>(</mo><mi>O</mi><mi>z</mi><mo>)</mo></mrow></math></span> axes to replace the mirror pressure iterative process of Hetenyi. The exact numerical values of these two correction factors are derived analytically. The results show that the free edge can substantially increase locally the contact pressure and therefore the stresses and displacement fields if close to the contact area. So the pressure field and the contact zone present an asymmetry which is more pronounced as the free edge is getting closer. This study is carried out on spaces with one, two and four free edges which will be respectively called: quarter-space, eighth-space and finite-length-space. A validation is performed using a Finite Element Method (FEM) analysis. A parametric study is also performed to exhibit the differences with the Hertz solution, including in the situation where one expects the truncation of the contact area when the free edge is virtually located within the Hertz contact area.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050177","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
On the dynamic shear failure of Ti-6Al-4V in different test specimen geometries 关于不同试样几何形状下 Ti-6Al-4V 的动态剪切破坏
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-22 DOI: 10.1016/j.ijsolstr.2024.113036

In this paper, the dynamic shear response and failure of Ti-6Al-4V using four different test specimen geometries, viz. Hat-Shaped Specimen (HSS), Flat Hat-Shaped Specimen (FHSS), Chip Hat-Shaped Specimen (CHSS) and Double Shear Specimen (DSS), are critically examined and compared. Through a combination of experiments (using the standard Split-Hopkinson Pressure Bar system), finite-element simulations and metallographic examinations of their fracture morphology, the dynamic shear characteristics (strain hardening, strain rate strengthening effect and failure strain) of Ti-6Al-4V obtained using the different specimen geometries are critically examined, compared and analyzed. It will be shown that differences in the stress/strain uniformity, the plastic deformation zone, and the stress state induced by the different specimen geometries lead to discrepancies in the measured shear response and failure that were observed. The shear stress–strain curve obtained using the DSS will be shown to be more precise than the other specimen geometries.

本文使用四种不同几何形状的试样(即帽形试样 (HSS)、平帽形试样 (FHSS)、片状帽形试样 (CHSS) 和双剪切试样 (DSS))对 Ti-6Al-4V 的动态剪切响应和破坏进行了批判性研究和比较。通过结合实验(使用标准的 Split-Hopkinson 压力棒系统)、有限元模拟和断口形貌的金相检查,对使用不同试样几何形状获得的 Ti-6Al-4V 动态剪切特性(应变硬化、应变速率强化效应和破坏应变)进行了严格的检查、比较和分析。结果表明,不同试样几何形状引起的应力/应变均匀性、塑性变形区和应力状态的差异导致测量的剪切响应和观察到的破坏存在差异。使用 DSS 得出的剪切应力-应变曲线将比其他试样几何形状更精确。
{"title":"On the dynamic shear failure of Ti-6Al-4V in different test specimen geometries","authors":"","doi":"10.1016/j.ijsolstr.2024.113036","DOIUrl":"10.1016/j.ijsolstr.2024.113036","url":null,"abstract":"<div><p>In this paper, the dynamic shear response and failure of Ti-6Al-4V using four different test specimen geometries, viz. Hat-Shaped Specimen (HSS), Flat Hat-Shaped Specimen (FHSS), Chip Hat-Shaped Specimen (CHSS) and Double Shear Specimen (DSS), are critically examined and compared. Through a combination of experiments (using the standard Split-Hopkinson Pressure Bar system), finite-element simulations and metallographic examinations of their fracture morphology, the dynamic shear characteristics (strain hardening, strain rate strengthening effect and failure strain) of Ti-6Al-4V obtained using the different specimen geometries are critically examined, compared and analyzed. It will be shown that differences in the stress/strain uniformity, the plastic deformation zone, and the stress state induced by the different specimen geometries lead to discrepancies in the measured shear response and failure that were observed. The shear stress–strain curve obtained using the DSS will be shown to be more precise than the other specimen geometries.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050174","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
Dynamic multifield continualization of multilayered lattice-like metamaterials 多层晶格状超材料的动态多场连续化
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-21 DOI: 10.1016/j.ijsolstr.2024.113015

This work focuses on dynamic continualization of multifield multilayered metamaterials in order to obtain energetically-consistent models able to provide an accurate description of the dispersive behavior of the corresponding discrete system. Continuum models, characterized by constitutive and inertial non-localities, have been identified through a recently proposed enhanced continualization scheme. They are identified by governing equations both of the integro-differential and higher-order gradient-type, whose regularization kernel or pseudo-differential functions accounting for shift operators are formally expanded in Taylor series. The adopted regularization kernel exhibits polar singularities at the edge of the first Brillouin zone, thus assuring the convergence of the frequency spectrum to the one of the Lagrangian system in the entire wave vector domain. The validity of the proposed approach is assessed through the investigation of multilayered discrete lattices with an antitetrachiral topology, where local resonators act as rigid links among the layers. The convergence of dispersion curves of the continuum model to the ones of the Lagrangian model is proved in the whole first Brillouin zone as the adopted continualization order increases, both considering the propagation and the spatial attenuation of Bloch waves inside the metamaterial. A low frequency continualization is also provided, leading to the identification of a first-order medium.

这项工作的重点是多场多层超材料的动态连续化,以获得能量一致的模型,从而准确描述相应离散系统的色散行为。通过最近提出的增强连续化方案,我们确定了以构成性和惯性非局部性为特征的连续模型。它们由积分微分方程和高阶梯度方程确定,这些方程的正则化核或伪微分函数考虑了移位算子,并以泰勒级数形式展开。所采用的正则化核在第一布里渊区边缘表现出极性奇点,从而确保在整个波矢量域的频谱趋同于拉格朗日系统的频谱。通过对具有反四螺旋拓扑结构的多层离散晶格的研究,评估了所提方法的有效性。考虑到布洛赫波在超材料内部的传播和空间衰减,随着所采用的连续化阶数增加,连续模型的频散曲线在整个第一布里渊区与拉格朗日模型的频散曲线趋同。此外,还提供了低频连续化,从而确定了一阶介质。
{"title":"Dynamic multifield continualization of multilayered lattice-like metamaterials","authors":"","doi":"10.1016/j.ijsolstr.2024.113015","DOIUrl":"10.1016/j.ijsolstr.2024.113015","url":null,"abstract":"<div><p>This work focuses on dynamic continualization of multifield multilayered metamaterials in order to obtain energetically-consistent models able to provide an accurate description of the dispersive behavior of the corresponding discrete system. Continuum models, characterized by constitutive and inertial non-localities, have been identified through a recently proposed enhanced continualization scheme. They are identified by governing equations both of the integro-differential and higher-order gradient-type, whose regularization kernel or pseudo-differential functions accounting for shift operators are formally expanded in Taylor series. The adopted regularization kernel exhibits polar singularities at the edge of the first Brillouin zone, thus assuring the convergence of the frequency spectrum to the one of the Lagrangian system in the entire wave vector domain. The validity of the proposed approach is assessed through the investigation of multilayered discrete lattices with an antitetrachiral topology, where local resonators act as rigid links among the layers. The convergence of dispersion curves of the continuum model to the ones of the Lagrangian model is proved in the whole first Brillouin zone as the adopted continualization order increases, both considering the propagation and the spatial attenuation of Bloch waves inside the metamaterial. A low frequency continualization is also provided, leading to the identification of a first-order medium.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020768324003743/pdfft?md5=597212dca5430bdb6b9620d82e760d3f&pid=1-s2.0-S0020768324003743-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142041162","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
Corrigendum to “A generalized strain model for nonlinear residually stressed magneto-electrically coupled viscoelastic solids” [Int. J. Solids Struct. 289 (2024) 112659] 对 "非线性残余应力磁电耦合粘弹性固体的广义应变模型 "的更正 [Int. J. Solids Struct.
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-21 DOI: 10.1016/j.ijsolstr.2024.112772
{"title":"Corrigendum to “A generalized strain model for nonlinear residually stressed magneto-electrically coupled viscoelastic solids” [Int. J. Solids Struct. 289 (2024) 112659]","authors":"","doi":"10.1016/j.ijsolstr.2024.112772","DOIUrl":"10.1016/j.ijsolstr.2024.112772","url":null,"abstract":"","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020768324001318/pdfft?md5=b0ecff12815b6530c5fc62e21d466f45&pid=1-s2.0-S0020768324001318-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142084370","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
Modeling of visco-electro-elastic responses of PZT-based functionally graded beam benders 基于 PZT 的功能分级梁弯曲机的粘弹响应建模
IF 3.4 3区 工程技术 Q1 MECHANICS Pub Date : 2024-08-20 DOI: 10.1016/j.ijsolstr.2024.113034

The modeling of the visco-electro-elastic behavior of functionally graded beam benders with PZT constituents is accomplished via a hierarchical framework that is based on the homogenization technique for composite layers and the laminate theory for a composite laminate. The representation of a bulk PZT constituent is based on linear visco-electro-elastic constitutive equations. The resulting bending displacements of PZT-graded bimorph and multimorph are obtained under the assumption of the Euler–Bernoulli beam. The experimental data of the bending displacements versus applied voltage are compared with the predictions for a bimorph and a multimorph, resulting in a good agreement. The responses of a bender to a complete cycle of applied voltage are shown in order to reveal the critical hysteretic actuation due to the presence of a visco-electro-elastic PZT material in a functionally graded piezoelectric beam bender which is made by functionally graded piezoelectric materials.

使用 PZT 成分的功能分级梁弯曲机的粘弹性行为建模是通过一个分层框架完成的,该框架基于复合材料层的均质化技术和复合材料层的层压板理论。块状 PZT 成分的表示是基于线性粘弹性构成方程。在欧拉-伯努利梁假设下,得到了 PZT 分级双晶和多晶的弯曲位移。弯曲位移与外加电压的实验数据与双晶和多晶的预测数据进行了比较,结果一致。为了揭示功能分级压电材料制成的功能分级压电弯梁机中由于粘弹性 PZT 材料的存在而产生的临界滞动,展示了弯梁机对施加电压的一个完整周期的响应。
{"title":"Modeling of visco-electro-elastic responses of PZT-based functionally graded beam benders","authors":"","doi":"10.1016/j.ijsolstr.2024.113034","DOIUrl":"10.1016/j.ijsolstr.2024.113034","url":null,"abstract":"<div><p>The modeling of the visco-electro-elastic behavior of functionally graded beam benders with PZT constituents is accomplished via a hierarchical framework that is based on the homogenization technique for composite layers and the laminate theory for a composite laminate. The representation of a bulk PZT constituent is based on linear visco-electro-elastic constitutive equations. The resulting bending displacements of PZT-graded bimorph and multimorph are obtained under the assumption of the Euler–Bernoulli beam. The experimental data of the bending displacements versus applied voltage are compared with the predictions for a bimorph and a multimorph, resulting in a good agreement. The responses of a bender to a complete cycle of applied voltage are shown in order to reveal the critical hysteretic actuation due to the presence of a visco-electro-elastic PZT material in a functionally graded piezoelectric beam bender which is made by functionally graded piezoelectric materials.</p></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142050176","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
期刊
International Journal of Solids and Structures
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