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【新文速递】2025年2月24日固体力学SCI期刊最新文章

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今日更新:International Journal of Solids and Structures 4 篇,Mechanics of Materials 1 篇,International Journal of Plasticity 2 篇

International Journal of Solids and Structures

Inverse calibration of out-of-plane shear anisotropy parameters of sheet metal

Bojan Starman, Tomaž Pepelnjak, Andraž Maček, Miroslav Halilovič, Sam Coppieters

doi:10.1016/j.ijsolstr.2025.113313

板料面外剪切各向异性参数的反校正

The accurate description of sheet metal forming processes such as blanking, riveting, incremental forming, and ironing strongly depends on understanding the material’s through-thickness shear resistance and plastic behavior. A three-dimensional model of plastic anisotropy is required to capture this behavior, but calibrating the out-of-plane shear parameters is often challenging. Researchers frequently assume isotropy or set the in-plane and out-of-plane shear parameters equal. More advanced approaches use a crystal plasticity model, which also requires calibration based on available material texture data. In this work, we introduce an out-of-plane shear test procedure that combines a macromechanical test with digital image correlation to inversely calibrate the shear anisotropy parameters of the YLD2004-18p yield function. This method efficiently characterizes both in-plane and out-of-plane shear anisotropy in medium-thick sheet metals.

准确描述钣金成形过程,如落料、铆接、增量成形和熨烫,在很大程度上取决于对材料的全厚度抗剪切性和塑性行为的理解。三维塑性各向异性模型需要捕捉这种行为,但校准面外剪切参数往往具有挑战性。研究人员经常假设各向同性或将面内和面外剪切参数设置为相等。更先进的方法使用晶体塑性模型,该模型也需要基于可用的材料纹理数据进行校准。在这项工作中,我们介绍了一种面外剪切试验程序,该程序将宏观力学试验与数字图像相关相结合,以反向校准YLD2004-18p屈服函数的剪切各向异性参数。该方法有效地表征了中厚金属板的面内和面外剪切各向异性。


Energy-based PINNs using the element integral approach and their enhancement for solid mechanics problems

Junwei Chen, Jianxiang Ma, Zhi Zhao, Xiaoping Zhou

doi:10.1016/j.ijsolstr.2025.113315

基于能量的单元积分pin及其对固体力学问题的改进

Despite the growing interest in physics-informed neural networks (PINNs) for computational mechanics, significant challenges remain in their widespread application. This work proposes an energy-based PINN method rooted in the principle of virtual work, which states that the external work done on a system is equal to its strain energy. This proposed method discretizes the model into nodes and constructs elements based on these nodes. The strain energy of each element is computed through numerical integration, and the total strain energy of the model is obtained by summing these elemental contributions. Simultaneously, the external work is calculated based on the nodal forces. These calculations, combined with the principle of virtual work, allow for the definition of the model’s physical properties. A deep neural network (DNN) is then trained to map the model’s coordinates to their corresponding displacements, utilizing the defined physical properties. Furthermore, this paper proposes a method to accelerate the learning process of energy-based PINNs by using a simpler and converged model to speed up convergence and to improve the overall accuracy of more complex models. Numerical results demonstrate that the proposed approach effectively solves stress concentration and singularity problems in solid mechanics with high accuracy.

尽管人们对物理信息神经网络(pinn)在计算力学中的应用越来越感兴趣,但在其广泛应用中仍存在重大挑战。这项工作提出了一种基于能量的PINN方法,该方法基于虚功原理,即对系统所做的外部功等于其应变能。该方法将模型离散为节点,并基于这些节点构造元素。通过数值积分计算各单元的应变能,将各单元的贡献相加得到模型的总应变能。同时,根据节点力计算外功。这些计算,结合虚功原理,可以定义模型的物理性质。然后训练深度神经网络(DNN)利用定义的物理属性将模型的坐标映射到相应的位移。此外,本文还提出了一种加速基于能量的pinn学习过程的方法,通过使用更简单和收敛的模型来加快收敛速度,并提高更复杂模型的整体精度。数值结果表明,该方法能有效地解决固体力学中的应力集中和奇点问题,精度较高。


Measurement and calculation method for circumferential plastic strain ratio of anisotropic aluminum alloy tubes

Xiao-Lei Cui, Qianxi Sun, Yichun Wang, Shijian Yuan

doi:10.1016/j.ijsolstr.2025.113311

各向异性铝合金管周向塑性应变比的测量与计算方法

To improve the finite element analysis (FEA) accuracy of forming hollow tubular components, it is urgent to determine the circumferential mechanical properties of thin-walled tube blanks, especially the plastic strain ratio rθ, and further investigate their anisotropic deformation and hardening behaviors. In this paper, a new segment-type ring expansion test (SRET) method was established for directly measuring rθ based on digital image correlation (DIC). It was shown by theoretical analysis that an approximately uniaxial and uniform stress state can be generated when the number of segments is 12 and the initial width-to-diameter ratio of the specimen is about 0.10. It was experimentally proved that the relative error of the measured rθ of 304 stainless steel welded tube was less than 1 % compared with the r-value of the original 304 sheet. Then, the rθ of aluminum alloy (6061) tubes was obtained by the SRET method, and the biaxial tensile deformation of the tubes was realized by a controllable biaxial tension test. It is shown that the axial and circumferential plastic strain ratios were 0.460 and 0.638, respectively. The strain path of equal-biaxial stress deviated from the equal-biaxial strain path, and the strain paths of σz/σθ= 0.75 and 1.333 (reciprocal) were asymmetrically distributed along the equal-biaxial strain line. These results indicate the tubes’ apparent anisotropic deformation behaviors. Finally, the effect of rθ and yield criterion on predicting the anisotropic hardening behavior was analyzed using the effective stress–strain curve. The results illustrate that rθ must be considered, and the Balart89 yield criterion with higher order has higher accuracy compared with the Hill48 yield criterion. This research is significant for improving and evaluating the prediction accuracy of plastic constitutive models.

为了提高空心管状件成形的有限元分析(FEA)精度,迫切需要确定薄壁管坯的周向力学性能,尤其是塑性应变比 rθ,并进一步研究其各向异性变形和硬化行为。本文基于数字图像相关(DIC)技术,建立了一种新的分段式环向扩张试验(SRET)方法,用于直接测量 rθ。理论分析表明,当分段数为 12 且试样初始宽度与直径之比约为 0.10 时,可产生近似单轴且均匀的应力状态。实验表明,304 不锈钢焊接管的 rθ 测量值与原始 304 板材的 r 值相比,相对误差小于 1%。然后,通过 SRET 方法获得了铝合金(6061)管的 rθ,并通过可控双轴拉伸试验实现了管材的双轴拉伸变形。结果表明,轴向和周向塑性应变比分别为 0.460 和 0.638。等双轴应力的应变路径偏离了等双轴应变路径,而 σz/σθ = 0.75 和 1.333(倒数)的应变路径沿等双轴应变线呈不对称分布。这些结果表明管材表现出明显的各向异性变形行为。最后,利用有效应力 - 应变曲线分析了 rθ 和屈服准则对预测各向异性硬化行为的影响。结果表明必须考虑 rθ,且与 Hill48 屈服准则相比,更高阶的 Balart89 屈服准则具有更高的精度。这项研究对于提高和评估塑性本构模型的预测精度具有重要意义。


Constitutive modelling and validating of annealed copper under various stress states, strain rates and temperatures

Yutian Du, Zejian Xu, Hongzhi Hu, Mengyu Su, Ang Hu, Fenglei Huang

doi:10.1016/j.ijsolstr.2025.113312

退火铜在不同应力状态、应变速率和温度下的本构建模和验证

Metallic materials and structures are often subjected to a wide range of strain, strain rate, temperature and stress state during the engineering application. In order to study the plastic and deformation characteristics of metallic materials under complex stress states, it is necessary to use a constitutive model that considers the effects of stress states. Based on shear specimens suitable for hydraulic Instron testing machines and Hopkinson bar systems (SHPB and SHTB), the compression-shear and tension-shear specimens are designed to achieve complex stress states. Through a combination of test and parallel finite element simulation, stress–strain curves of the material under various stress states were obtained. Additionally, mechanical property tests were conducted on specimens under typical stress states (uniaxial compression, uniaxial tension, and shear) at a wide range of strain rates and temperatures. To describe the plastic mechanical behavior of materials, a new plastic constitutive model considering temperature, strain rate, and stress state is proposed. Then the model was embedded into the ABAQUS/Explicit finite element software through the VUMAT user material subroutine for numerical simulation. The performance of the new model was systematically compared and analyzed with that of Johnson-Cook model and Xu et al.’s model. The ability of the prediction of plastic deformation in Taylor impact test was evaluated for different models. The results show that the new constitutive model is suitable for predicting the impact deformation associated with complex strain rates, temperatures, and stress states.

在工程应用过程中,金属材料和结构往往要承受大范围的应变、应变速率、温度和应力状态。为了研究复杂应力状态下金属材料的塑性和变形特性,有必要采用考虑应力状态影响的本构模型。以适用于液压压力试验机和霍普金森杆系统(SHPB和SHTB)的剪切试件为基础,设计了压剪和拉剪试件,以实现复杂的应力状态。通过试验与平行有限元模拟相结合,得到了材料在不同应力状态下的应力应变曲线。此外,在较宽的应变速率和温度范围内,对试件进行了典型应力状态(单轴压缩、单轴拉伸和剪切)下的力学性能测试。为了描述材料的塑性力学行为,提出了一种考虑温度、应变速率和应力状态的塑性本构模型。然后通过VUMAT用户材料子程序将模型嵌入到ABAQUS/Explicit有限元软件中进行数值模拟。将新模型的性能与Johnson-Cook模型和Xu等人的模型进行了系统的比较和分析。对不同模型在Taylor冲击试验中预测塑性变形的能力进行了评价。结果表明,该本构模型适用于复杂应变率、温度和应力状态下的冲击变形预测。


Mechanics of Materials

A poroelastic model of the optic nerve shows a significant effect of fluid pressure on the nerve fibers.

Denis Kucherenko, Arina Korneva

doi:10.1016/j.mechmat.2025.105299

视神经的孔弹性模型显示了流体压力对神经纤维的显著影响。

The structure of the optic nerve resembles a cylindrical composite where the pia mater surrounds the nervous tissue which is saturated with interstitial fluid. This interstitial fluid is necessary for effective nerve conduction of visual signals. The reaction of the optic nerve to physiological loads remains unknown. Current computational and material models do not fully capture the complexities of this tissue’s structure, particularly the biofluid has not yet been considered as a load-supporting material. We developed a microstructurally motivated analytical model of a cylindrical composite with a poroelastic core and an elastic outer layer subjected to an axial load. We examined the effect of the geometry and the material parameters of the composite on the stress distribution across the composite. We found physiologically relevant conditions when the outer layer and the biofluid support most of the applied stress relative to the solid constituents of the core. The model shows that the fluid pressure can be as large as one third of the applied stress. The model makes possible the fluid pressure injuring nerve fibers. This scenario is missing in studies modeling the optic nerve as an elastic solid. We examined how variations in outer layer thickness and compressibility of animal nerves or materials stiffen the stress-strain response. This study provides guidelines for measuring and comparing the material parameters between diseased, aged, and healthy nerves and similar biomaterials. The model can be used to analyze mechanics of similar composites.

视神经的结构类似于一个圆柱形的复合物,其中软脑膜包围着充满间质液的神经组织。这种间质液对于视觉信号的有效神经传导是必要的。视神经对生理负荷的反应尚不清楚。目前的计算和材料模型并没有完全捕捉到这种组织结构的复杂性,特别是生物流体尚未被认为是一种负载支撑材料。我们开发了一个微观结构驱动的圆柱形复合材料的分析模型,具有孔弹性核心和弹性外层受到轴向载荷。我们研究了复合材料的几何形状和材料参数对复合材料应力分布的影响。我们发现了与生理相关的条件,当外层和生物流体相对于核心的固体成分支持大部分施加的应力时。该模型表明,流体压力可达施加应力的三分之一。该模型使液体压力损伤神经纤维成为可能。在将视神经建模为弹性固体的研究中,这种情况是缺失的。我们研究了动物神经或材料的外层厚度和可压缩性的变化如何使应力-应变反应变硬。本研究为测量和比较患病、衰老和健康神经与类似生物材料之间的材料参数提供了指导。该模型可用于类似复合材料的力学分析。


International Journal of Plasticity

Manipulating the interfacial structures in titanium alloys containing interstitial solutes delivers ultra-high strength and ductility

Hang Zhang, Xuanzhe Li, Jinyu Zhang, Suzhi Li, Shaohua Gao, Gang Liu, Jun Sun

doi:10.1016/j.ijplas.2025.104288

控制含间隙溶质的钛合金的界面结构可提供超高的强度和延展性

Design structural characteristics of interfaces is the key for ultra-strong titanium (Ti) alloys by tuning polymorphic α-precipitates. However, the conventional tri-modal structure, characterized by various interfaces, usually shows large ductility but low yield strength caused by numerous soft α-precipitates. This work focuses on manipulating multiple interfacial structures to endow a newly designed tri-modal Ti-4.9Al-4.4Cr-2.45Mo-1.6Zr alloys with the superior strength-ductility synergy assisted by interstitial solutes, beyond conventional high-strength Ti alloys. Here, an interstitial solute alloying strategy is utilized not only to form hard-yet-deformable α-precipitates, but also to achieve the controllably stepwise α-precipitation sequence to manipulate interfacial structures and thus slip transmission modes in Ti alloys. In particular, the coherent twin boundaries (CTBs) between secondary α-nanolamellae formed via dislocation-interstitial atom interactions can efficiently hinder dislocation motion but promote dislocation transmission in the soft transformed β-matrix. This strategy provides new insights into designing high-performance interstitial solute-tolerant alloys for cost-effective and lightweight applications.

设计界面结构特征是调整多晶α-析出物的关键。而传统的三模态结构,由于界面多样,由于α-软相较多,塑性大,屈服强度低。本工作的重点是操纵多个界面结构,赋予新设计的三模态Ti-4.9 al -4.4 cr -2.45 mo -1.6 zr合金在间隙溶质的辅助下具有优于传统高强度钛合金的强度-塑性协同作用。本文采用间隙溶质合金化策略,不仅可以形成坚硬且可变形的α-析出相,还可以实现可控制的逐步α-析出序列,从而控制界面结构,从而改变Ti合金中的滑移传递模式。特别是,位错-间隙原子相互作用形成的次生α-纳米片间的相干孪晶界(CTBs)可以有效地阻碍位错运动,但促进位错在软相变β-基体中的传递。这一策略为设计具有成本效益和轻量化应用的高性能间质耐溶质合金提供了新的见解。


Effect of precipitate phase on the plastic deformation behavior of Alloy 718: in-situ tensile experiment and crystal plasticity simulation

Guanghao Guo, Wenqiang Zhang, Bin Zhang, Jiachen Xu, Shuang Chen, Xianjue Ye, Yuefei Zhang, Ze Zhang

doi:10.1016/j.ijplas.2025.104286

析出相对718合金塑性变形行为的影响:原位拉伸实验与晶体塑性模拟

In this study, in-situ tensile experiments were conducted on three samples containing different precipitate phases (δ, γ″ and γ′) to investigate the effects of these precipitates on the tensile deformation mechanisms of Alloy 718. Local plastic deformation was characterized by digital image correlation (DIC) and electron back-scatter diffraction (EBSD). The plasticity was analyzed in terms of slip, lattice rotation, slip transfer, and intergranular cooperative deformation. The dislocation accumulation is slower in the γ matrix, promoting uniform plastic deformation within grains via single slip, resulting in excellent intragranular deformation capability for the sample without any precipitates. In contrast, the γ″ and γ′ phases facilitate dislocation multiplication and impede dislocation motion, causing rapid dislocation pile-up within grains, leading to local stress concentrations. These stress concentrations can activate secondary slip systems early, resulting in uneven intragranular deformation and limiting the grains’ plastic deformation capacity for the sample with γ′′ and γ′. At grain boundaries, the δ phase hinders slip transfer, restricting the capacity for intergranular coordinated deformation, resulting in the formation of microcracks along the grain boundaries. These microcracks, along both the δ phase and the grain boundaries, contribute to the reduction in plasticity of the sample with δ phase. The effects of γ″ and γ′ phases are similar, as they limit grain deformation by influencing dislocation accumulation within grains, while the δ phase at grain boundaries reduces the tensile plasticity of Alloy 718 by impeding intergranular deformation coordination.

通过原位拉伸实验,研究了不同析出相(δ、γ″和γ′)对718合金拉伸变形机制的影响。采用数字图像相关(DIC)和电子背散射衍射(EBSD)对局部塑性变形进行了表征。从滑移、晶格旋转、滑移传递和晶间协同变形等方面分析了材料的塑性。位错在γ基体中的积累速度较慢,通过单次滑移促进晶粒内均匀的塑性变形,从而使样品具有良好的晶内变形能力,且无析出物。相反,γ″和γ′相促进位错增殖,阻碍位错运动,导致位错在晶粒内快速堆积,导致局部应力集中。这些应力集中可以早期激活二次滑移系统,导致晶内变形不均匀,限制了γ′和γ′试样的塑性变形能力。在晶界处,δ相阻碍了滑移转移,限制了晶间协调变形的能力,导致沿晶界形成微裂纹。沿δ相和晶界的微裂纹导致δ相试样的塑性降低。γ″和γ′相的作用相似,它们通过影响位错在晶内的积累来限制晶粒变形,而晶界处的δ相通过阻碍晶间变形配位来降低合金718的拉伸塑性。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemAbaqusDeform复合材料电子焊接裂纹理论材料物流控制试验钣金
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【新文速递】2025年2月23日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 1 篇,Mechanics of Materials 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 6 篇International Journal of Solids and StructuresGreen’s functions of size-dependent Timoshenko beams: Gradient elasticity versus stress-driven nonlocal theoriesNoël Challamel, Ahmad Aftabi Sanidoi:10.1016/j.ijsolstr.2025.113308尺寸相关Timoshenko梁的Green函数:梯度弹性与应力驱动的非局部理论In this article, Timoshenko elastic nano-beams modeled by three different models (stress-driven nonlocal integral model, strain gradient elastic model without transversal strain gradient, and strain gradient elastic model with transversal strain gradient effect) are analyzed by the help of Green’s function method. Conventionally, the governing boundary value problem (BVP) for Timoshenko nano-beams consists of two differential equations (DEs) and six boundary conditions (BCs) with two unknown dependent variables, i.e., (1) the cross-sectional rotation function, and (2) the transverse displacement field. In the stress-driven model, this multi-field problem is converted into a new single-field BVP including a single higher order DE with only one dependent variable. Obviously, this recent problem needs some new BCs which are rigorously derived in the second step of formulation. The third, and in fact, the last step of the proposed formulation is to solve the new organized BVP by the means of Green’ function. However, in the strain gradient model, the BVP consists of two six-order DEs with two unknown functions. Also, this problem includes twelve boundary conditions which eight of them are “decoupled” and four of them are “coupled” which should be solved simultaneously. To the best of knowledge to the researchers, the current study is a first successful attempt to solve a BVP with some “coupled” boundary conditions by Green’s function. As an instance, the Green’s function of simply supported Timoshenko nano-beams is obtained for both (1) stress-driven nonlocal integral model, and (2) strain gradient elastic model which, respectively, contain symmetric and non-symmetric kernels. Alongside the graphical presentation of the Green’s functions, the results of all models are presented for several loading including the distributed loads expressed by the help of polynomials with higher degrees (equal or more than two) and sinusoidal distributed loading.本文利用格林函数法对应力驱动非局部积分模型、不含横向应变梯度的应变梯度弹性模型和具有横向应变梯度效应的应变梯度弹性模型三种不同模型下的Timoshenko弹性纳米梁进行了分析。通常,Timoshenko纳米梁的控制边值问题(BVP)由两个微分方程(DEs)和六个边界条件(bc)组成,其中两个未知因变量为(1)截面旋转函数和(2)横向位移场。在应力驱动模型中,这个多场问题被转化为一个新的单场问题,其中包含一个只有一个因变量的高阶DE。显然,这个新问题需要一些新的bc,这些bc是在第二步公式中严格推导出来的。第三步,实际上也是最后一步,是通过Green函数来解决新的有组织的BVP。然而,在应变梯度模型中,BVP由两个具有两个未知函数的六阶微分方程组成。同时,该问题包含12个边界条件,其中8个是“解耦”的,4个是“耦合”的,需要同时求解。据研究人员所知,目前的研究是第一次成功地尝试用格林函数求解具有一些“耦合”边界条件的BVP。以包含对称核和非对称核的(1)应力驱动非局部积分模型和(2)应变梯度弹性模型为例,得到了简支Timoshenko纳米梁的Green函数。除了格林函数的图形表示外,还给出了几种荷载的所有模型的结果,包括由高次多项式(等于或大于2次)表示的分布荷载和正弦分布荷载。Mechanics of MaterialsNovel uniaxial and biaxial reverse experiments for material parameter identification in an advanced anisotropic cyclic plastic-damage modelZhichao Wei, Steffen Gerke, Michael Brünigdoi:10.1016/j.mechmat.2025.105294在先进的各向异性循环塑性损伤模型中进行材料参数识别的新型单轴和双轴反向试验This paper discusses the calibration and verification of material parameters based on novel one-axis and biaxial reverse experiments. The uniaxially loaded tension-compression (TC-), one-axis-loaded shear, and biaxially loaded HC-specimens are designed to perform different cyclic experiments, covering a wide range of stress triaxialities. Special anti-buckling clamping jaws and a newly designed downholder are used during the experiments to avoid buckling under compression loads. During the experiments, strain fields are recorded and analyzed using the digital image correlation (DIC) technique. A combination of direct and indirect fitting approaches is employed to identify the essential elastic–plastic material parameters for the proposed advanced elastic–plastic-damage constitutive model. The characterization of damage parameters is not discussed in this paper. A quantitative error analysis method is introduced to check the quality of the numerical simulation using the obtained material parameters. The comparison between experimental and numerical results demonstrates that the proposed damage model with identified parameters can predict global load–displacement curves and local strain fields with good accuracy.本文讨论了基于新型单轴和双轴反实验的材料参数标定与验证。单轴加载的拉伸压缩(TC-)、单轴加载的剪切和双轴加载的hc -试件进行不同的循环试验,涵盖了广泛的应力三轴性。实验中采用了特殊的防屈曲夹爪和新设计的下托器,以避免在压缩载荷下的屈曲。在实验过程中,利用数字图像相关技术记录和分析了应变场。采用直接拟合和间接拟合相结合的方法,对所提出的先进弹塑性损伤本构模型的基本弹塑性材料参数进行识别。本文未讨论损伤参数的表征。介绍了一种定量误差分析方法,利用得到的材料参数检验数值模拟的质量。实验结果与数值结果的对比表明,基于识别参数的损伤模型能够较好地预测整体载荷-位移曲线和局部应变场。International Journal of PlasticityEnhancing fatigue life of low-carbon ultra-high strength steel by inducing multi-component precipitatesXiaocong Yang, Yuezhang Ju, Chengning Li, Chang Gao, Lingzhi Ba, Shipin Wu, Ce Wang, Taihao Ding, Ying Wang, Xinjie Didoi:10.1016/j.ijplas.2025.104287 通过诱导多组分析出提高低碳超高强度钢的疲劳寿命In this study, the low-carbon ultra-high-strength steels with precipitation-free were prepared using quenching processes, and the co-precipitation strengthening of multi-scale Cu-rich and NiAl were designed to enhance fatigue performance through quenching-tempering (QT) and quenching-partitioning-tempering (QPT) processes respectively. The microstructure of quenched steel shows a typical mixed microstructure of lath martensite (LM) and granular bainite (GB). After aging at 550 °C for 1 h, the high density (1.945 × 1023 m-3) of B2-NiAl and B2 core-9R shell nanoparticles were uniformly co-precipitated and greatly increased the yield strength and high-cycle fatigue strength from 965 MPa and 384.6 MPa to 1548 MPa and 510.7 MPa, respectively. The substantial improvement in fatigue performance is attributed to the large number of small-sized nanoparticles that hinder the movement of dislocations to form high-density dislocation tangles (HDDTs) and cell structures, reducing the stress concentration at grain boundaries. Furthermore, geometric phase analysis (GPA) revealed the existence of micro-strain around small-sized multi-component precipitates, which is less likely to cause micro-crack initiation, thereby enhancing the fatigue performance. After QPT treatment, the co-precipitated nanoparticles exhibited multi-scale distribution with a significantly reduced number density of 1.005 × 1023 m-3, and the typical large-sized FCC-Cu particles are identified, which weakens the precipitation strengthening and leads to the yield strength and fatigue strength reached 1396 MPa and 424.5 MPa respectively. Furthermore, the GNDs obviously accumulate at the interface between reversed austenite (RA) and matrix by the movement of dislocations and bypassed nanoparticles, which increases the tendency of microcrack initiation at the interface. In addition, the high strain accumulated at the interface of FCC-Cu particles increases the risk of fatigue damage and limits the improvement of fatigue performance.本研究采用淬火工艺制备了无析出的低碳超高强度钢,设计了多尺度富cu和NiAl共析出强化,分别通过调质(QT)和淬火-配分-回火(QPT)工艺提高疲劳性能。淬火钢的组织为典型的条状马氏体(LM)和粒状贝氏体(GB)混合组织。550℃时效1 h后,高密度(1.945 × 1023 m-3)的B2- nial纳米粒子和B2核- 9r壳纳米粒子均匀共析出,屈服强度和高周疲劳强度分别从965 MPa和384.6 MPa大幅提高到1548 MPa和510.7 MPa。大量的小尺寸纳米颗粒阻碍了位错的移动,形成高密度位错缠结(HDDTs)和细胞结构,减少了晶界处的应力集中,从而显著改善了疲劳性能。此外,几何相分析(GPA)表明,小尺寸多组分析出物周围存在微应变,不易引发微裂纹,从而提高了疲劳性能。经QPT处理后,共析出的纳米颗粒呈多尺度分布,数量密度显著降低,为1.005 × 1023 m-3,具有典型的大尺寸FCC-Cu颗粒,其析出强化减弱,屈服强度和疲劳强度分别达到1396 MPa和424.5 MPa。此外,由于位错和旁路纳米颗粒的运动,gds在逆奥氏体与基体的界面处明显富集,增加了界面处微裂纹萌生的倾向。此外,FCC-Cu颗粒界面处积累的高应变增加了疲劳损伤的风险,限制了疲劳性能的提高。Thin-Walled StructuresCompressive failure mechanisms of fibre metal laminates with 2/1 and 3/2 configurations after low-velocity impactZheng-Qiang Cheng, Jie Xia, Hu Liu, Zhi-Wu Zhu, Wei Tandoi:10.1016/j.tws.2025.113112低速冲击后2/1和3/2结构金属纤维层合板压缩破坏机理The residual compressive strength after low-velocity impact (LVI) serves as a pivotal metric for assessing the damage tolerance of composite structures. This paper aims to elucidate the compressive failure mechanisms of glass fibre/aluminium fibre metal laminates (FMLs) that have incurred initial LVI damage, meanwhile illustrating the effects of fibre orientation, impact energy and laminate configuration on the compressive failure behaviours of FMLs. Initially, specific impact damage was prefabricated and examined in FMLs with 2/1 and 3/2 configurations. Quasi-static compression tests were then conducted to analyse the global force versus displacement responses and local strain evolution of FMLs during compressive loading. Furthermore, visual inspection, ultrasonic C-scan, and CT-scan were employed to explain the damage morphologies and failure mechanisms of FMLs. Finally, the comparative analysis of the compression after impact (CAI) strengths was conducted for different FMLs. The results demonstrate that fibre orientation, impact energy and laminate configuration significantly affect the compressive mechanical responses and damage morphologies of FMLs. Moreover, FMLs experience a 40%-61% decrease in compressive strength after LVI within the energy range from 35 J to 65 J. Additionally, the 3/2 configuration is a more advantageous laminate design than the 2/1 configuration in terms of specific CAI strength and residual strength ratio. This research contributes novel insights into the impact damage tolerance of FMLs, which hold promise as load-bearing structural materials in aeronautic applications.低速冲击后的残余抗压强度是评价复合材料结构损伤容限的关键指标。本文旨在阐明发生初始LVI损伤的玻璃纤维/铝纤维金属层压板(FMLs)的压缩破坏机制,同时说明纤维取向、冲击能和层压板构型对FMLs压缩破坏行为的影响。最初,在2/1和3/2结构的FMLs中预制和检查特定的冲击损伤。然后进行了准静态压缩试验,分析了压缩加载过程中FMLs的整体力-位移响应和局部应变演变。此外,采用目视检查、超声c -扫描和ct扫描来解释FMLs的损伤形态和破坏机制。最后,对不同FMLs的冲击后压缩强度进行了对比分析。结果表明,纤维取向、冲击能和层状结构对FMLs的压缩力学响应和损伤形态有显著影响。此外,在35 J ~ 65 J的能量范围内,LVI后fml的抗压强度下降了40% ~ 61%。此外,在比CAI强度和残余强度比方面,3/2配置比2/1配置更有利。该研究为FMLs的冲击损伤容限提供了新的见解,FMLs有望成为航空应用中的承重结构材料。Dynamic response analysis of wind turbine tower with high aspect ratio: Wind tunnel tests and CFD simulationDong Li, Yuan Sang, Zhihao Lv, Keda Wu, Zhichao Laidoi:10.1016/j.tws.2025.113113大展弦比风力机塔架动力响应分析:风洞试验与CFD模拟With larger rotors and taller towers developed to capture more wind energy, the wind turbine structures are becoming more flexible with aspect ratio increasing. However, there remains a strong gap of dynamic analysis of fully coupled high-aspect-ratio wind turbine tower system. This study employed the IEA 15 WM wind turbine as a reference prototype, and designed a scaled model based on the geometric, kinematic, and dynamic similarity principles. Then, the systematic investigations of dynamic behavior of coupled wind turbine tower system were performed tested combined wind tunnel tests with computational fluid dynamics (CFD) modelling. The dynamic behavior was analyzed in terms of acceleration and displacement responses, motion trajectories, and dynamic characteristics in both crosswind and downwind directions. In CFD modelling, the aerodynamic characteristics were revealed in terms of the average pressure coefficient, fluctuating pressure coefficient, and lift and drag forces. Parameter discussions were performed including the blade rotation, turbulence intensity and wind speed. The results indicate that turbine vibrations are highly sensitive to variations in wind speed and turbulence. As wind speed and turbulence increase, the range of vibration data expands, with peak responses amplified by 249.70% and 59.63%, respectively, and lift forces increasing by over 40%. Furthermore, blade rotation increases the average pressure coefficient by up to 42.09%. Compared to the previous studies of low-aspect-ratio wind turbine tower case, high-aspect-ratio wind turbine tower exhibit significantly more intense vibrations in the same operating cases, with an increase in the root mean square (RMS) of acceleration up to 52.50%. Additionally, the slender tower structures are more susceptible to higher-order frequency excitations induced by fluid solid interactions during operation.随着更大的转子和更高的塔的发展,以捕获更多的风能,风力涡轮机结构变得更加灵活,宽高比增加。然而,对于全耦合大展弦比风力机塔架系统的动力学分析,目前还存在较大的空白。本研究以IEA 15wm风力机为参考原型,基于几何、运动学和动力学相似原理设计了比例模型。在此基础上,采用计算流体力学(CFD)建模的方法,对耦合风塔系统的动力特性进行了系统的研究。从加速度和位移响应、运动轨迹以及侧风和下风方向的动力特性等方面分析了其动力特性。在CFD建模中,从平均压力系数、波动压力系数、升力和阻力等方面揭示了气动特性。对叶片转速、湍流强度、风速等参数进行了讨论。结果表明,涡轮振动对风速和湍流的变化非常敏感。随着风速和湍流度的增加,振动数据范围扩大,峰值响应分别放大了249.70%和59.63%,升力增加了40%以上。叶片旋转可使平均压力系数提高42.09%。与以往研究的低展弦比风机塔架工况相比,在相同工况下,高展弦比风机塔架振动强度明显增强,加速度均方根(RMS)提高了52.50%。此外,细长的塔结构在运行过程中更容易受到流固相互作用引起的高阶频率激励。Nonlinear forced vibration and stability analysis of a rotating three-dimensional cantilever beam with variable cross-sectionHang Li, Guo Yaodoi:10.1016/j.tws.2025.113104变截面旋转三维悬臂梁的非线性强迫振动及稳定性分析This article investigates the nonlinear forced vibration of a rotating three-dimensional variable cross-section cantilever beam under uniformly distributed harmonic loads. Incorporating the effects of Coriolis terms, static axial deformation, and geometric nonlinearity, the nonlinear partial differential equations for a rotating variable cross-section Euler-Bernoulli beam are derived using Hamilton's principle. The Galerkin method discretizes these equations into nonlinear ordinary differential equations. Numerical simulations are conducted to present the amplitude-frequency and time-history responses, illustrating the nonlinear dynamic characteristics of the rotating variable cross-section cantilever beam. The effects of rotational speed, hub radius, excitation amplitude, and cross-section change rate on the stability, nonlinear principal resonance, and superharmonic resonance of the rotating beam system are discussed. Results show the fundamental natural frequency increases with the increase of the hub radius, rotational speed, and cross-section change rate. Furthermore, the cross-section change rate significantly impacts the nonlinear vibration response of the system.本文研究了均布谐波荷载作用下旋转三维变截面悬臂梁的非线性强迫振动问题。结合科里奥利项、静态轴向变形和几何非线性的影响,利用汉密尔顿原理推导了旋转变截面欧拉-伯努利梁的非线性偏微分方程。伽辽金方法将这些方程离散为非线性常微分方程。通过数值模拟,给出了旋转变截面悬臂梁的幅频响应和时程响应,揭示了其非线性动力特性。讨论了转速、轮毂半径、激励幅值和截面变化率对旋转梁系统稳定性、非线性主共振和超谐波共振的影响。结果表明:基频随轮毂半径、转速和截面变化率的增大而增大;此外,截面变化率对系统的非线性振动响应有显著影响。Creep behavior modeling of nickel-based superalloy foil structures in gas foil bearingsZhenni Xu, Chaozhe Jin, Changlin Li, Jianjun Dudoi:10.1016/j.tws.2025.113105气体箔轴承中镍基高温合金箔结构蠕变行为建模Gas foil bearings are self-acting aerodynamic bearings that use nickel-based superalloy foil structures as the load-carrying element. This type of bearing has great potential in high-temperature and high-speed turbomachinery but faces serious challenges in maintaining a long service life in extreme environments. Creep behaviors of foil structures are inevitable when the bearings are exposed to high temperatures for prolonged periods. In this paper, we innovatively propose a finite element model to investigate the steady-state creep behavior of foil structures, considering both the creep effects and nonlinear contact behaviors. Uniaxial creep tests are conducted using miniature specimens to obtain the material constants in the Norton creep model of Inconel 718. The reasonability of the model is verified by comparing predictions with the ANSYS simulation results, demonstrating its ability to accurately describe the evolution of creep displacement, stress, and strain in foil structures. The significant differences in creep displacements at different positions of the foil structure are explained by analyzing the distributions of equivalent stress and principal stress. Overall, the bump foil exhibits more pronounced creep displacements than the top foil, especially in the peak region of bumps and the flat segment between adjacent bumps near the free end.气体箔轴承是采用镍基高温合金箔结构作为承载元件的自作用气动轴承。这种类型的轴承在高温和高速涡轮机械中具有很大的潜力,但在极端环境中保持较长的使用寿命面临着严峻的挑战。当轴承长时间暴露在高温下时,箔结构的蠕变行为是不可避免的。在本文中,我们创新地提出了一个有限元模型来研究箔结构的稳态蠕变行为,同时考虑了蠕变效应和非线性接触行为。采用微型试样进行了单轴蠕变试验,得到了Inconel 718的Norton蠕变模型中的材料常数。通过与ANSYS仿真结果的对比,验证了该模型的合理性,证明了该模型能够准确地描述箔片结构的蠕变位移、应力和应变的演化过程。通过分析等效应力和主应力的分布,解释了箔片结构不同位置蠕变位移的显著差异。总体而言,凸起箔比顶部箔表现出更明显的蠕变位移,特别是在凸起的峰值区域和靠近自由端的相邻凸起之间的平坦段。A Deep Learning Method for Addressing the Scarcity of Experimental Data in Composite Structures: Multi-Fidelity Triple LSTMKairui Tang, Yiyang Cui, Puhui Chendoi:10.1016/j.tws.2025.113106 一种解决复合结构中实验数据稀缺性的深度学习方法:多保真度三重LSTMHigh-precision numerical simulations and physical experiments for composite structure design are costly and limited. Neural networks offer a promising solution, but conventional models rely heavily on large amount of high-fidelity data and struggle to handle the complex variable space introduced by layup sequences. This paper proposes a deep learning model—Multi-Fidelity Triple LSTM (MF-T-LSTM)—to predict composite mechanical properties using limited test samples. The model uses one LSTM to capture layup sequences and two others to process data at different fidelity levels. The MF-T-LSTM model is applied to predict the tensile load-displacement curve of composite open-hole laminates. A combination of limited experiments and extensive FEM simulations generated the training dataset. The model's components (LSTM-MLP and Dual LSTM) were validated before development. The MF-T-LSTM achieved high prediction accuracy, with an average R 2 of 0.918 on the experimental test set. Quantitative analysis demonstrated its low dependence on low-fidelity (LF) data quality and strong transferability across different LF datasets. Replacing LF dataset with less accurate versions led to only a 1.4% average drop in performance. These results underscore the MF-T-LSTM model's advantages in predicting composite mechanical responses and reducing experimental costs.用于复合材料结构设计的高精度数值模拟和物理实验成本高且有局限性。神经网络提供了一个很有前途的解决方案,但传统的模型严重依赖于大量高保真度的数据,并且难以处理由分层序列引入的复杂变量空间。本文提出了一种深度学习模型-多保真度三重LSTM (MF-T-LSTM)来利用有限的测试样本预测复合材料的力学性能。该模型使用一个LSTM捕获叠加序列,另外两个LSTM以不同的保真度处理数据。应用MF-T-LSTM模型预测复合材料开孔层合板的拉伸载荷-位移曲线。有限的实验和广泛的FEM模拟相结合产生了训练数据集。模型的组件(LSTM- mlp和Dual LSTM)在开发前进行了验证。MF-T-LSTM具有较高的预测精度,平均R 2的0.918在实验测试集上。定量分析表明,该方法对低保真度数据质量的依赖性较低,在不同低保真度数据集之间具有较强的可移植性。用不太准确的版本替换LF数据集只会导致性能平均下降1.4%。这些结果强调了MF-T-LSTM模型在预测复合材料力学响应和降低实验成本方面的优势。Theoretical, experimental, and numerical investigations on friction-metallic hybrid asynchronized-type double-stage shear damperCantian Yang, Linlin Xie, Hang Sun, Huiyong Ban, Bingyan Liu, Aiqun Lidoi:10.1016/j.tws.2025.113107摩擦-金属混合异步式双级剪切阻尼器的理论、实验和数值研究In this study, a novel friction-metallic hybrid asynchronized-type double-stage shear damper (FMHADSD) was developed. The FMHADSD consists of two frictional units, one asynchronously-activated metallic-yielding unit, and upper and lower ending plates. The FMHADSD is expected to exhibit a double-stage working mechanism. The theoretical equations for the quadrilinear skeleton curve of the FMHADSD were proposed. Full-scale dampers were then designed and tested, and the double-stage working mechanism and performance of the FMHADSD were verified. Furthermore, a refined numerical investigation was conducted to analyze stress distribution and validate the rationality of the FMHADSD configuration. Subsequently, a uniaxial material model was developed and implemented in OpenSees to simulate the hysteretic behavior of FMHADSD, providing an accurate and efficient approach for the seismic response analysis of structures equipped with FMHADSDs.研制了一种新型的摩擦-金属混合异步式双级剪切阻尼器(FMHADSD)。FMHADSD由两个摩擦单元、一个异步激活的金属屈服单元以及上下端板组成。预计fmhasd将采用双阶段工作机制。建立了FMHADSD四线性骨架曲线的理论方程。设计并测试了全尺寸阻尼器,验证了双级阻尼器的工作机理和性能。此外,还进行了精细化的数值研究,分析了fmhasd结构的应力分布,验证了结构的合理性。随后,在OpenSees中开发并实现了单轴材料模型来模拟FMHADSD的滞回行为,为配备FMHADSD的结构的地震反应分析提供了准确有效的方法。来源:复合材料力学仿真Composites FEM

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