Journal of The Mechanics and Physics of Solids最新文献_第6页

Wavelength selection in the twist buckling of pre-strained elastic ribbons 预应变弹性带扭曲屈曲中的波长选择

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-24 DOI: 10.1016/j.jmps.2024.106005

Arun Kumar, Basile Audoly

A competition between short- and long-wavelength twist buckling instabilities has been reported in experiments on thin elastic ribbons having pre-strain concentrated in a rectangular region surrounding the axis. The wavelength of the twisting mode has been reported to either scale (i) as the width of the ribbon when the pre-strain is large (short-wavelength case) or (ii) as the length of the ribbon when the pre-strain is small (large-wavelength case). Existing one-dimensional rod or ribbon models can only account for large-wavelength buckling. We derive a novel one-dimensional model that accounts for short-wavelength buckling as well. It is derived from non-linear shell theory by dimension reduction and captures in an asymptotically correct way both the non-convex dependence of the strain energy on the twisting strain

τ

(which causes buckling) and its dependence on the strain gradient

τ^{'}

. The competition between short- and long-wavelength buckling is shown to be governed by the sign of the incremental elastic modulus

B_{0}

associated with the twist gradient

τ^{'}

. The one-dimensional model reproduces the main features of equilibrium configurations generated in earlier work using 3D finite-element simulations. In passing, we introduce a novel truncation strategy applicable to higher-order dimension reduction that preserves the positiveness of the strain energy even when the gradient modulus is negative,

B_{0} < 0

.

在预应变集中在轴周围矩形区域的薄弹性带实验中，报道了短波长扭曲屈曲不稳定性之间的竞争。据报道，扭转模式的波长为(i)预应变较大时（短波长情况下）的条带宽度，或（ii）预应变较小时（大波长情况下）的条带长度。现有的一维棒状或带状模型只能解释大波长的屈曲。我们推导了一个新的一维模型，该模型也考虑了短波屈曲。它是通过降维从非线性壳理论推导出来的，并以渐进正确的方式捕获了应变能对扭转应变τ（导致屈曲）的非凸依赖性及其对应变梯度τ '的依赖性。短波长屈曲之间的竞争被证明是由与扭转梯度τ '相关的增量弹性模量B0的符号所控制的。一维模型利用三维有限元模拟再现了早期工作中产生的平衡构型的主要特征。同时，我们引入了一种新的截断策略，适用于高阶降维，即使梯度模量为负，也能保持应变能的正性。

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引用次数: 0

A length-scale insensitive cohesive phase-field interface model: Application to concurrent bulk and interface fracture simulation in Lithium-ion battery materials 一种长度尺度不敏感内聚相场界面模型：在锂离子电池材料体裂和界面断裂模拟中的应用

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-21 DOI: 10.1016/j.jmps.2024.106013

Wan-Xin Chen , Xiang-Long Peng , Jian-Ying Wu , Orkun Furat , Volker Schmidt , Bai-Xiang Xu

A new cohesive phase-field (CPF) interface fracture model is proposed in this paper. It employs an exponential function for the interpolation of fracture energy between the bulk phase and the interface, and its effective interface fracture energy is solved based on the Euler–Lagrange equation of the phase-field theory and the consistency to the cohesive zone model (CZM) in the sharp interface concept. Comparison to other interface models in the literature clearly shows that the above energy consistency is essential to ensure the insensitivity of the results to the length-scale parameters for regularization of the crack surface and of the interface. The proposed interface model can be conveniently implemented via the relaxation solution of an Allen–Cahn equation, which offers high flexibility in handling structures of complicated interface topology. The proposed CPF interface model is employed further to derive a thermodynamically consistent chemo-mechanical model relevant to Lithium-ion battery materials. Finite-element simulations confirm the model’s ability to recapture the competition between bulk and interface fractures, while also demonstrate its merits of length-scale insensitivity and consistency with CZM results. The model is eventually applied in polycrystalline electrode particles, which are reconstructed from images with segmented interfaces, confirming the expected computational advantages and the length-scale insensitivity in multi-physical context.

提出了一种新的内聚相场（CPF）界面断裂模型。采用指数函数插值体相与界面之间的断裂能，基于相场理论的欧拉-拉格朗日方程和与尖锐界面概念中的内聚区模型（CZM）的一致性求解有效界面断裂能。与文献中其他界面模型的比较清楚地表明，上述能量一致性对于保证裂纹表面和界面正则化结果对长度尺度参数的不敏感性至关重要。所提出的界面模型可以方便地通过Allen-Cahn方程的松弛解实现，对于处理复杂的界面拓扑结构具有很高的灵活性。利用所提出的CPF界面模型进一步推导出与锂离子电池材料相关的热力学一致的化学力学模型。有限元模拟证实了该模型能够重现体裂缝和界面裂缝之间的竞争，同时也证明了其长度尺度不敏感和与CZM结果一致的优点。该模型最终应用于多晶电极颗粒，该模型由具有分割界面的图像重建，证实了预期的计算优势和多物理环境下的长度尺度不敏感性。

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引用次数: 0

Macroscopically modeling fatigue life of additively manufactured metals: Pore-defect informed phase-field model 增材制造金属疲劳寿命的宏观建模：孔隙缺陷通知相场模型

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-20 DOI: 10.1016/j.jmps.2024.106008

Wei Tang , Lingfeng Wang , Shen Sun , Liucheng Zhou , Min Yi

Fatigue crack growth (FCG) behavior and fatigue life of additively manufactured (AM) materials are highly sensitive to AM-induced pore defects, thus challenging the traditional fatigue models. A model customized for predicting fatigue/fracture behavior of AM materials is indispensable. Here we propose a pore-defect informed phase-field model (PFM) for the macroscopic modeling of fatigue crack initiation (FCI), FCG, and fatigue life of AM metals. The macroscopic PFM integrates pore-defect fatigue (PDF) model of AM metals, local stress–strain approach and cumulative fatigue damage theory. The PDF model correlates AM pore features (i.e., size, location, and morphology) with fatigue life and its parameters can be readily determined by fatigue test of standard specimens of AM metals. Our PFM is confirmed to be capable of predicting both

S

(

E

)–

N

curves and Paris’ law of AM metallic (nickel base superalloy Hastelloy X, titanium alloy TC4 and TC17) specimens over low- and high-cycle fatigue regimes, and the predictions are found to agree well with experiments. For a simulated compressor blade fabricated by laser AM, our three-dimensional PFM simulations of FCI and FCG behaviors could correctly predict the critical crack length and fatigue limit, which accord with experimental results obtained by X-ray computer tomography and vibration fatigue test. The pore-defect informed PFM framework here could provide a practicable toolkit for the rapid evaluation of fatigue life of AM components, as well as for the computational prediction and design of fatigue-resistant AM components.

增材制造（AM）材料的疲劳裂纹扩展（FCG）行为和疲劳寿命对AM诱导的孔隙缺陷高度敏感，这对传统的疲劳模型提出了挑战。为预测AM材料的疲劳/断裂行为而定制的模型是必不可少的。在这里，我们提出了一种孔隙缺陷通知相场模型（PFM），用于AM金属疲劳裂纹萌生（FCI）， FCG和疲劳寿命的宏观建模。宏观PFM综合了AM金属的孔缺陷疲劳模型、局部应力-应变方法和累积疲劳损伤理论。PDF模型将AM孔特征（即尺寸、位置和形态）与疲劳寿命联系起来，其参数可以很容易地通过AM金属标准试样的疲劳试验确定。我们的PFM被证实能够预测AM金属（镍基高温合金哈氏合金X，钛合金TC4和TC17）试样在低周和高周疲劳状态下的S (E) - n曲线和Paris定律，并且预测结果与实验结果一致。对于激光增材制造的模拟压气机叶片，本文的FCI和FCG行为三维PFM模拟能够正确预测临界裂纹长度和疲劳极限，与x射线计算机断层扫描和振动疲劳试验结果一致。该框架可为快速评估增材制造部件的疲劳寿命，以及抗疲劳增材制造部件的计算预测和设计提供实用的工具。

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引用次数: 0

Interfacial fracture in soft solids — How geometry and viscoplasticity make crack fronts unstable

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-17 DOI: 10.1016/j.jmps.2024.105979

Pierre-Yves Corbel , Paul Fourton , Paul Elzière , Keyvan Piroird , Matteo Ciccotti , Etienne Barthel

Polyvinylbutyral (PVB) is a polymer with sizeable viscoelastic dissipation at room temperature. It is often used in laminated glass to impart shock resistance to glazings. We have investigated adhesion rupture in glass/PVB interfaces in the through crack tensile test (TCT) geometry, representative of laminated glass rupture. We find that even though, in the high velocity range, interfacial rupture apparently follows the linear viscoelastic predictions, at low velocity a much richer behavior appears: the system bifurcates, the front undulates, and at still lower velocities, it stops. Such instabilities cannot be explained by linear viscoelastic fracture. Prompted by the measured tensile response of PVB at high strain rates/low temperatures, we have explored steady state viscoplastic fracture, using a generic numerical model. The results show that the TCT geometry enhances the viscoplastic response in the rupture process. They also demonstrate that with viscoplasticity, the rupture energy decreases with velocity, a characteristic which indeed accounts for the observed crack front instabilities. We further discuss the implications of these findings for a better understanding of adhesion and rupture in soft matter and their connection to viscoplasticity.

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引用次数: 0

Grain refinement in metal microparticles subjected to high impact velocities 金属微粒在高冲击速度下的晶粒细化

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-17 DOI: 10.1016/j.jmps.2024.106009

Chongxi Yuan, Marisol Koslowski

High-strain rate deformation caused by microparticles impacting at high velocities is used to refine the microstructure of metallic materials to the nanocrystalline regime. Under these conditions, metallic targets and particles show a gradient distribution of nanograins, with size increasing away from the impact surface. Some of the mechanisms responsible for the refinement process are still not fully understood. We present finite element simulations of single-crystal and polycrystalline aluminum

20 μ m

particles impacting a sapphire substrate at velocities ranging from 50 m/s to 500 m/s. The model includes finite deformation crystal plasticity, a contact algorithm, and an equation of state for high strain rate response. We study the effect of crystal orientation on the restitution coefficient, the permanent deformation of the particle, and grain refinement. The extreme deformation of the particle during the impact results in a high dislocation density and lattice rotation that develop a microstructure with a gradient distribution of grains that are smaller near the impact surface. The size of the new grains scales linearly with the inverse of the average stress in the particle.

利用微粒高速撞击引起的高应变速率变形将金属材料的微观结构细化到纳米晶状态。在此条件下，金属靶和颗粒呈现出纳米颗粒的梯度分布，远离撞击面，尺寸逐渐增大。一些负责细化过程的机制仍然没有被完全理解。本文对单晶和多晶铝20μm颗粒以50 ~ 500 m/s的速度撞击蓝宝石衬底进行了有限元模拟。该模型包括有限变形晶体塑性、接触算法和高应变率响应状态方程。研究了晶粒取向对恢复系数、晶粒永久变形和晶粒细化的影响。在冲击过程中，颗粒的极端变形导致了高位错密度和晶格旋转，从而形成了靠近冲击表面的晶粒梯度分布的微观结构。新晶粒的大小与颗粒中平均应力的反比成线性关系。

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引用次数: 0

Mechanistic cohesive zone laws for fatigue cracks: Nonlinear field projection and in situ synchrotron X-ray diffraction (S-XRD) measurements 疲劳裂纹的力学黏结带规律：非线性场投影和原位同步x射线衍射（S-XRD）测量

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-16 DOI: 10.1016/j.jmps.2024.106010

H. Tran , D. Xie , P.K. Liaw , H.B. Chew , Y.F. Gao

A weak interface model with a predefined traction-separation relationship (denoted as the cohesive zone law), when embedded in a bulk solid, is oftentimes adopted to simulate the crack advancement and thus determine the crack resistance under either monotonic or cyclic loading conditions. To-date, various types of loading-unloading irreversibility and hysteresis are only presumed in the cohesive zone law for fatigue crack growth, but without any direct determination from experimental measurements. Using a fine-grained Mg alloy and synchrotron X-ray diffraction (S-XRD) measurements with a sub-millimeter beam, in situ lattice strain mapping can be obtained with the needed resolution to cover both the “messy” process zone as modeled by the cohesive zone law and the “clean” process zone caused by plastic deformation. We extend our previously developed nonlinear field projection method, and create trial elastic fields from the S-XRD-measured elastic strain fields at different loading levels when choosing the fully unloaded state as the new reference. From the Maxwell-Betti's reciprocal theorem, we reconstruct a mechanistic cohesive zone law for fatigue cracks, where the reciprocity gap is governed by the residual stress field at the fully unloaded state. Combining our inverse approach with S-XRD measurements, it is discovered that the fatigue-crack cohesive zone exhibits a bilinear unloading and reloading behavior that is distinctively different than all prior works. This particular form suggests the origin of irreversibility be primarily from crack-surface oxidation and the hysteresis from dislocation plasticity in surrounding grains.

嵌入块体时，通常采用具有预先定义的牵引-分离关系的弱界面模型（称为黏聚区定律）来模拟裂纹的发展，从而确定单调或循环加载条件下的裂纹抗力。迄今为止，疲劳裂纹扩展的粘聚区规律中仅假定了各种类型的加载-卸载不可逆性和迟滞性，而没有从实验测量中直接确定。利用细晶镁合金和亚毫米光束同步加速器x射线衍射（S-XRD）测量，可以获得所需分辨率的原位点阵应变映射，以覆盖由内聚区定律模拟的“凌乱”过程区和由塑性变形引起的“干净”过程区。我们扩展了已有的非线性场投影方法，在选择完全卸载状态作为新的参考时，从s - xrd测量的不同加载水平下的弹性应变场中创建了试验弹性场。本文从Maxwell-Betti互易定理出发，重构了疲劳裂纹的机械内聚区规律，其中互易间隙由完全卸载状态下的残余应力场控制。将我们的反方法与S-XRD测量相结合，发现疲劳裂纹黏聚区表现出双线性卸载和再加载行为，这与所有先前的研究结果明显不同。这种特殊的形式表明，不可逆性的来源主要是裂纹表面氧化和周围晶粒位错塑性的迟滞。

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引用次数: 0

Quantifying 3D time-resolved kinematics and kinetics during rapid granular compaction, Part II: Dynamics of heterogeneous pore collapse 在快速颗粒压实过程中量化三维时间分辨运动学和动力学，第二部分：非均质孔隙坍塌动力学

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-16 DOI: 10.1016/j.jmps.2024.106007

Sohanjit Ghosh , Mohmad M. Thakur , Ryan C. Hurley

Pores in granular materials may occupy significant material volume. Pore-scale dynamics, therefore, strongly influence the macroscopic response of these materials when they are subjected to rapid compaction. In Part I of this series, Ghosh et al. (2024) employed in-situ X-ray imaging coupled with mesoscale finite element modeling to reconstruct the 3D time-resolved kinematics and kinetics of aluminum and soda lime glass powders subjected to rapid compaction. In Part II of this series, presented here, we use the same approach to examine the dynamics of the pores and the phenomenon of pore collapse during rapid compaction while also expanding our materials of interest to include Ottawa sand. We find that pore collapse is a highly spatially and temporally heterogeneous process in which pores reach their maximum compacted states across a broad range of timescales dictated by local microstructure, boundary conditions, and grain interactions. Using our data, we assess the validity of common pressure-based (

P

-

α

) and strain-based (

ϵ

-

α

) porosity evolution models at different length scales, and as a function of grain size, strain rate, and material ductility. We emphasize the importance of boundary conditions when interpreting theoretical porosity evolution models. Overall, our study provides deep new insight into pore collapse and porosity evolution during rapid granular compaction and highlights the importance of accounting for heterogeneous porosity evolution when modeling this process.

颗粒状材料中的孔隙可能占用大量的材料体积。因此，当这些材料受到快速压实时，孔隙尺度动力学会强烈影响它们的宏观响应。在本系列的第一部分中，Ghosh等人（2024）采用原位x射线成像与中尺度有限元建模相结合，重建了快速压实作用下铝和钠石灰玻璃粉的三维时间分辨运动学和动力学。在本系列的第二部分中，我们使用相同的方法来检查孔隙的动力学和孔隙在快速压实过程中的崩溃现象，同时也扩展了我们感兴趣的材料，包括渥太华砂。我们发现孔隙坍缩是一个高度空间和时间非均匀的过程，在这个过程中，孔隙在由局部微观结构、边界条件和颗粒相互作用决定的广泛时间尺度上达到最大压实状态。利用我们的数据，我们评估了常见的基于压力（P-α）和基于应变（λ -α）的孔隙度演化模型在不同长度尺度下的有效性，以及作为晶粒尺寸、应变速率和材料延性的函数。在解释理论孔隙度演化模型时，我们强调边界条件的重要性。总的来说，我们的研究为快速颗粒压实过程中的孔隙崩塌和孔隙演化提供了深刻的新见解，并强调了在模拟这一过程时考虑非均质孔隙演化的重要性。

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引用次数: 0

Optimization of constitutive law for objective numerical modeling of knitted fabric 针织物本构规律优化的客观数值模拟

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-16 DOI: 10.1016/j.jmps.2024.106017

Agnieszka Tomaszewska, Daniil Reznikov

This paper discusses the problem of macroscopic modeling a knitted technical fabric with the aim to determine a constitutive law for adequately modeling the material response under real-life load. As phenomenological, hyperelastic material laws reveal different parameters due to different test modalities used to identify such parameters, an optimization scheme is proposed to determine an objective solution. The study is conducted for three medical textiles which are differentiated by anisotropy ratios and designed to cover abdominal hernia. The optimization parameters are defined by a constitutive law and the bi-axial test modality. State variables are taken from ex-vivo reference tests on ‘operated’ hernia models subjected to simulated real-life loads generated by post-operative coughs. The objective function is different for isotropic and anisotropic mesh. However, in both cases a numerical model of a mesh placed in the abdominal wall with different variants of the constitutive law is used. The model is constructed according to the finite element method framework. The objective function for isotropic mesh is defined by the variance of reaction forces in mesh fixation points, calculated in the numerical model, while for anisotropic mesh, it is generated by the difference between angles which determine the position of maximal reaction force in the numerical and experimental reference models. Three constitutive laws and five modalities of bi-axial tests are considered. This analysis proves the need for a constitutive model, itself validated by a suitable reference test, instead of an arbitrary decision on bi-axial test modality selected to identify the material law parameters. These conclusions may help to increase the reliability of numerical modeling of operated hernia and increase the effectiveness of hernia treatment.

本文讨论了针织工业织物的宏观建模问题，目的是确定一个本构律，以充分模拟材料在实际载荷下的响应。由于采用不同的测试方式来识别超弹性材料的参数，超弹性材料的现象性规律会显示出不同的参数，因此提出了一种优化方案来确定客观解。以三种医用纺织品为研究对象，采用各向异性比例进行区分，设计用于覆盖腹疝。利用本构律和双轴试验模态确定了优化参数。状态变量取自“手术”疝气模型的离体参考试验，该模型承受由术后咳嗽产生的模拟现实负荷。各向同性网格和各向异性网格的目标函数是不同的。然而，在这两种情况下，一个网格的数值模型放置在腹壁与不同变体的本构律被使用。该模型是根据有限元法框架建立的。各向异性网格的目标函数是由数值模型中计算的网格固定点反作用力的方差来定义的，而各向异性网格的目标函数是由数值模型和实验参考模型中决定最大反作用力位置的角度差产生的。考虑了三种本构规律和五种双轴试验模态。这一分析证明，需要一个本构模型，本身通过适当的参考试验验证，而不是任意决定选择双轴试验模态来识别材料规律参数。这些结论有助于提高手术疝数值模拟的可靠性，提高疝治疗的有效性。

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引用次数: 0

A continuum geometric approach for inverse design of origami structures 折纸结构反设计的连续统几何方法

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-14 DOI: 10.1016/j.jmps.2024.106003

Alon Sardas , Michael Moshe , Cy Maor

Miura-Ori, a celebrated origami pattern that facilitates functionality in matter, has found multiple applications in the field of mechanical metamaterials. Modifications of Miura-Ori pattern can produce curved configurations during folding, thereby enhancing its potential functionalities. Thus, a key challenge in designing generalized Miura-Ori structures is to tailor their folding patterns to achieve desired geometries. In this work, we address this inverse-design problem by developing a new continuum framework for the differential geometry of generalized Miura-Ori. By assuming that the perturbation to the classical Miura-Ori is slowly varying in space, we derive analytical relations between geometrical properties and the perturbation field. These relationships are shown to be invertible, allowing us to design complex curved geometries. Our framework enables porting knowledge, methods and tools from continuum theories of matter and differential geometry to the field of origami metamaterials.

Miura-Ori是一种著名的折纸图案，它促进了物质的功能，已经在机械超材料领域找到了多种应用。对Miura-Ori模式的修改可以在折叠过程中产生弯曲的结构，从而增强其潜在的功能。因此，设计广义Miura-Ori结构的一个关键挑战是定制它们的折叠模式以达到所需的几何形状。在这项工作中，我们通过为广义Miura-Ori的微分几何开发一个新的连续体框架来解决这个反设计问题。通过假设经典Miura-Ori的扰动在空间中是缓慢变化的，我们推导出几何性质与扰动场之间的解析关系。这些关系被证明是可逆的，允许我们设计复杂的弯曲几何。我们的框架能够将物质和微分几何的连续统理论的知识，方法和工具移植到折纸超材料领域。

引用次数: 0

Enhanced cyclic stability of NiTi shape memory alloy elastocaloric materials with Ni4Ti3 nanoprecipitates: Experiment and phase field modeling Ni4Ti3纳米沉淀物增强NiTi形状记忆合金弹热材料的循环稳定性：实验与相场模拟

IF 5 2区工程技术 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of The Mechanics and Physics of Solids

Pub Date : 2024-12-14 DOI: 10.1016/j.jmps.2024.106011

Bo Xu , Xu Xiao , Qixing Zhang , Chao Yu , Di Song , Qianhua Kan , Chong Wang , Qingyuan Wang , Guozheng Kang

In this work, a NiTi shape memory alloy (SMA) with excellent elastocaloric performance (with an ultrahigh coefficient of performance, i.e., COP_mat of ∼46.5 and an adiabatic temperature change of ∼10.5 K) and good cyclic stability is prepared. A thermo-mechanically coupled and crystal-plasticity-based phase field model including both the descriptions of Ni₄Ti₃ precipitation and martensitic transformation (MT) is newly proposed to reveal the microscopic mechanism behind the cyclic stability of NiTi elastocaloric materials. The dependence of plasticity on the precipitate size is innovatively considered through a Hall-Petch-like relationship between the dislocation slip resistance and the distance between adjacent precipitates, and the pinning effect of dislocation on reverse MT is reflected by introducing an interaction energy. The elastocaloric effect (eCE) and its cyclic evolution of the single-crystal NiTi SMA systems containing Ni₄Ti₃ precipitates with different sizes are simulated. Combined with experimental observations and simulations, new insights are provided on the mechanism behind the enhanced cyclic stability of precipitation strengthened NiTi SMA elastocaloric materials. The results of this work can improve the valuable scheme and theoretical basis for the development of NiTi-based elastocaloric materials with outstanding eCE and good cyclic stability.

在这项工作中，制备了一种具有优异弹热性能（具有超高性能系数，即COPmat为~ 46.5，绝热温度变化为~ 10.5 K）和良好循环稳定性的NiTi形状记忆合金（SMA）。为了揭示NiTi弹热材料循环稳定性的微观机制，提出了一种包括Ni4Ti3析出和马氏体相变（MT）描述的基于热机械耦合和晶体塑性的相场模型。创新性地考虑了塑性对析出相尺寸的依赖，将位错滑移阻力与相邻析出相之间的距离建立了Hall-Petch-like关系，并通过引入相互作用能来反映位错对反向MT的钉住效应。模拟了含不同尺寸Ni4Ti3相的单晶NiTi SMA体系的弹性热效应及其循环演化过程。结合实验观测和模拟，对沉淀强化NiTi SMA弹性热材料循环稳定性增强的机理提供了新的见解。研究结果为开发具有优异eCE和良好循环稳定性的镍基弹性热材料提供了有价值的方案和理论基础。

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引用次数: 0