今日更新：International Journal of Solids and Structures 2 篇，International Journal of Plasticity 3 篇，Thin-Walled Structures 3 篇International Journal of Solids and StructuresNumerical analyses of brittle crack growth experiments in compression using a modified phase-field theoryP. Hesammokri, P. Isakssondoi:10.1016/j.ijsolstr.2024.112815基于修正相场理论的压缩脆性裂纹扩展实验数值分析There has been a huge interest in recent years in using phase-field theories for numerical analyses of fracture phenomena. However, in phase-field fracture theories, a critical aspect often involves a decomposition of the strain energy density to select physically trustworthy crack paths and to prevent interpenetration of crack surfaces. This aspect becomes even more critical in the case of mixed-mode loading under compression. To overcome these challenges, a hydrostatic-spectral-deviatoric decomposition, enhanced by separate critical energy release rates for different fracture modes, is employed in this study. In order to evaluate the enhanced decomposition strategy, a set of biaxially loaded crack experiments in global compression is designed. Samples of different geometries contain multiple flaws and holes. The experiments are numerically simulated using a unified set of material parameters and three different strain energy decomposition methods (i.e., hydrostatic-spectral-deviatoric, spectral and hydrostatic-deviatoric). Simulations using the hydrostatic-spectral-deviatoric decomposition scheme capture both intricate crack paths and critical loads in the experiments. Hence, the enhanced decomposition strategy seems capable of simulating the experiments with reasonable precision, in sharp contrast to the two commonly used decomposition strategies (spectral and hydrostatic-deviatoric).近年来，相场理论在断裂现象数值分析中的应用引起了人们极大的兴趣。然而，在相场断裂理论中，一个关键的方面往往涉及到应变能密度的分解，以选择物理上可靠的裂纹路径，并防止裂纹表面的互渗。在压缩下的混合模式加载情况下，这一点变得更加重要。为了克服这些挑战，本研究采用了流体静力-光谱-偏差分解，并通过不同裂缝模式的不同临界能量释放率来增强。为了对增强分解策略进行评价，设计了一套全局压缩双轴加载裂纹实验。不同几何形状的样品包含多个缺陷和孔洞。采用统一的材料参数集和三种不同的应变能分解方法(静水-谱-偏、谱和静水-偏)对实验进行了数值模拟。采用静流体-频谱-偏差分解方案的模拟捕获了实验中复杂的裂纹路径和临界载荷。因此，增强的分解策略似乎能够以合理的精度模拟实验，与两种常用的分解策略(频谱和静水偏差)形成鲜明对比。Mechanics of crack initiation, propagation and crack grain boundary interaction in bicrystal silicon using near-tip localized stress calculationSunil Kumar Dutta, Gaurav Singhdoi:10.1016/j.ijsolstr.2024.112811基于近尖端局部应力计算的双晶硅裂纹萌生、扩展及裂纹晶界相互作用力学Crack propagation and arrest are important phenomena in polycrystalline silicon. This phenomenon considerably affects the effectiveness of solar cells made up of polycrystalline silicon. To understand the crack propagation in polycrystalline silicon, it is essential to study the bicrystal first. Earlier, crack propagation has been studied in bicrystal materials primarily from the perspective of material behaviour. However, the mechanics part is largely missing. In the present work, crack propagation of bicrystal silicon during uniaxial tension has been studied at the atomistic scale. The silicon bicrystal was formed by joining two single crystals: crystal 1 and crystal 2 of different orientations. Various stages like crack initiation, propagation, arrest, re-initiation and crack grain boundary (GB) interaction have been analysed using Stress Intensity Factor (SIF), calculated from the local crack tip virial stress field. Considering the effect of crack tip velocity, the dynamic SIFs at crack propagation stage have been converted to the SIF of an equivalent static crack using the generalised expression for anisotropic material. It has been found that for the propagation stage, crack propagation continues as long as the equivalent static SIF is greater than the critical SIF (CSIF). In crystal 1, crack propagation is along the low CSIF direction. Therefore, the crack did not change its path and propagated along a straight line. On the other hand, when the crack enters to crystal 2, it follows a zigzag path. Both of these observations have been justified in terms of near-tip calculated SIFs.裂纹扩展和止裂是多晶硅中的重要现象。这一现象极大地影响了多晶硅太阳能电池的效率。为了了解多晶硅的裂纹扩展规律，必须首先研究双晶。以前，双晶材料的裂纹扩展主要是从材料行为的角度来研究的。然而，机制部分却被忽略了。本文在原子尺度上研究了双晶硅在单轴拉伸过程中的裂纹扩展。硅双晶是由两个不同取向的单晶:晶体1和晶体2连接而成的。利用应力强度因子(SIF)分析了裂纹萌生、扩展、止裂、再萌生和裂纹晶界(GB)相互作用的各个阶段。考虑裂纹尖端速度的影响，采用各向异性材料的广义表达式将裂纹扩展阶段的动态SIF转换为等效静态裂纹的SIF。研究发现，在扩展阶段，只要等效静态SIF大于临界SIF (CSIF)，裂纹就会继续扩展。在晶体1中，裂纹沿低CSIF方向扩展。因此，裂缝不改变其路径，沿直线传播。另一方面，当裂纹进入晶体2时，它遵循一个之字形路径。根据近尖端计算的sif，这两种观察结果都是合理的。International Journal of PlasticityExperimental Investigation and Numerical Modelling of the Cyclic Plasticity and Fatigue Behavior of Additively Manufactured 316L Stainless SteelM. Subasic, A. Ireland, R. Mansour, P. Enblom, P. Krakhmalev, M. Åsberg, A. Fazi, J. Gårdstam, J. Shipley, P. Waernqvist, B. Forssgren, P. Efsingdoi:10.1016/j.ijplas.2024.103966增材制造316L不锈钢循环塑性与疲劳行为的试验研究与数值模拟This study addresses the critical need for a constitutive model to analyze the cyclic plasticity of additively manufactured 316L stainless steel. The anisotropic behavior at both room temperature and 300°C is investigated experimentally based on cyclic hysteresis loops performed in different orientations with respect to the build direction. A comprehensive constitutive model is proposed, that integrates the Armstrong-Frederick nonlinear kinematic hardening, Voce nonlinear isotropic hardening and Hill's anisotropic yield criterion within a 3D return mapping algorithm. The model was calibrated to specimens in the 0° and 90° orientations and validated with specimens in the 45° orientation. A single set of hardening parameters successfully represented the elastoplastic response for all orientations at room temperature. The algorithm effectively captured the full cyclic hysteresis loops, including historical effects observed in experimental tests. A consistent trend of reduced hardening was observed at elevated temperature, while the 45° specimen orientation consistently exhibited the highest degree of strain hardening. The applicability of the model was demonstrated by computing energy dissipation for stabilized hysteresis loops, which was combined with fatigue tests to propose an energy-based fatigue life prediction model.本研究解决了对增材制造316L不锈钢循环塑性分析本构模型的迫切需要。实验研究了室温和300℃下不同方向的循环迟滞环的各向异性行为。提出了一种将Armstrong-Frederick非线性运动硬化、Voce非线性各向同性硬化和Hill各向异性屈服准则集成在三维返回映射算法中的综合本构模型。对0°和90°方向的试样进行了标定，并对45°方向的试样进行了验证。一组硬化参数成功地代表了室温下所有取向的弹塑性响应。该算法有效地捕获了全循环迟滞回路，包括在实验测试中观察到的历史效应。在高温下，试样的硬化程度降低，而在45°取向时，试样的应变硬化程度最高。通过对稳定滞回线能量耗散的计算，验证了该模型的适用性，并结合疲劳试验提出了基于能量的疲劳寿命预测模型。Advancement of microstructural evolution and deformation mechanisms in AA6082 aluminum alloy under elevated-temperature tensile loadingOleksandr Lypchanskyi, Karol Janus, Daniel Irmer, Anna Wójcik, Grzegorz Korpała, Ulrich Prahldoi:10.1016/j.ijplas.2024.103969 高温拉伸载荷下AA6082铝合金组织演变及变形机制研究进展This study explores the intricate interplay between strain-induced precipitation (SIP) and the underlying mechanisms that govern hot deformation in AA6082 aluminum alloy. Uniaxial tensile tests were conducted at elevated temperatures, ranging from 200°C to 400°C, and varied strain rates from 0.01 s−1 to 10 s−1. Employing advanced methodologies such as scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), energy dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the research investigates the relationship between deformation, precipitation, and structural evolution. At lower strain rates, longer deformation times promote dynamic recrystallization, thereby promoting the growth of substructures with enhanced ductility. On the contrary, at higher strain rates (10 s−1), shorter deformation times inhibit such processes, resulting in a clear predominance of dislocation motion along specific slip systems and consequently influencing the mechanical response of the alloy. The results also reveal temperature-dependent deformation mechanisms, such as intragrain slip, continuous dynamic recrystallization (CDRX), and SIP phenomena, which influence the alloy's mechanical response. At 200°C, prominent work hardening dominates, while 400°C exhibits dynamic softening mechanisms. EBSD analyzes elucidate temperature-specific deformation mechanisms, including intragrain slip at 200°C and transitional phenomena at 300°C. Microstructural analysis at 200°C reveals the absence of needle- or rod-shaped precipitates. On the contrary, at 300°C, the presence of β/β' precipitates significantly influences the nucleation of β'' precipitates at the grain boundaries. At 400°C, substantial rod-shaped β' phase precipitates appear, demonstrating a complex interplay between diffusion mechanisms and strain-induced effects. In addition, the study also investigated the fracture behavior of aluminum alloy at different tensile temperatures, revealing the transition from transgranular fracture at 200°C to intergranular fracture at 300°C, as well as the shear effect of β/β' phase precipitates at this temperature. The findings provide a comprehensive understanding of the alloy behavior under diverse conditions, essential to optimize its processing parameters and mechanical properties.本研究探讨了AA6082铝合金中应变诱导析出(SIP)之间复杂的相互作用和控制热变形的潜在机制。单轴拉伸试验在高温下进行，温度范围从200°C到400°C，应变速率从0.01 s−1到10 s−1。采用先进的方法，如扫描电子显微镜(SEM)、电子背散射衍射(EBSD)、能量色散x射线光谱(EDS)和透射电子显微镜(TEM)，研究了变形、沉淀和结构演化之间的关系。在较低的应变速率下，较长的变形时间促进了动态再结晶，从而促进了子结构的生长，增强了延性。相反，在较高的应变速率下(10 s−1)，较短的变形时间抑制了这一过程，导致沿特定滑移系统的位错运动明显占优势，从而影响了合金的力学响应。结果还揭示了影响合金力学响应的温度相关变形机制，如晶内滑移、连续动态再结晶(CDRX)和SIP现象。在200°C时，主要是加工硬化，而在400°C时表现为动态软化机制。EBSD分析阐明了温度特定的变形机制，包括200°C时的晶内滑移和300°C时的过渡现象。在200°C下的显微组织分析显示没有针状或棒状的沉淀。相反，在300℃时，β/β′相的存在对晶界处β′相的形核有显著影响。在400℃时，大量棒状β′相析出，表明扩散机制和应变诱导效应之间存在复杂的相互作用。此外，本研究还研究了铝合金在不同拉伸温度下的断裂行为，揭示了铝合金在200℃时的穿晶断裂向300℃时的沿晶断裂的转变，以及在该温度下β/β′相析出物的剪切作用。研究结果提供了对合金在不同条件下行为的全面了解，对优化其加工参数和力学性能至关重要。A new failure criterion for predicting meso/micro-scale forming limit of composite metal foilsLihuang Zheng, Jeong Whan Yoondoi:10.1016/j.ijplas.2024.103962一种预测复合金属箔中、微观尺度成形极限的失效准则In order to design robust and reliable micro forming processes for composite metal foils, it is crucial to accurately forecast their forming limit under various strain paths. To date, however, there are few criteria that can effectively predict the forming limit of composite metal foils influenced by size effect. To solve this problem, a new uncoupled failure criterion is developed in this study, which considers the effects of interfacial layer, free surface roughening, grain size and strain path of heterogeneous materials, based on the deformation characteristic and failure mechanism of composite metal foils. Subsequently, it is presented the methodology for calculating the material constants of the proposed failure model. Additionally, the experimental forming limit strains of Ni/Cu clad foils with various grain sizes are utilized to show the prediction capability of the proposed model. To further confirm the application capability of the new failure criterion in practical micro forming, the finite element method incorporating the proposed criterion is employed to predict the failure behavior of Ni/Cu clad foil micro-channels in rubber pad forming. Comparisons indicate that the proposed model can accurately capture the forming limit of the composite metal foils influenced by size effect. This work provides a new scientific basis for determining the forming limit of composite metal foils.为了设计坚固可靠的复合金属箔微成形工艺，准确预测复合金属箔在各种应变路径下的成形极限是至关重要的。然而，迄今为止，能够有效预测受尺寸效应影响的复合金属箔成形极限的准则很少。为解决这一问题，本文基于复合金属箔的变形特性和破坏机理，建立了考虑界面层、自由表面粗化、晶粒尺寸和非均质材料应变路径影响的非耦合破坏准则。然后，给出了计算所提出的破坏模型的材料常数的方法。此外，利用不同晶粒尺寸的Ni/Cu覆层箔的实验成形极限应变来验证该模型的预测能力。为了进一步验证新失效准则在实际微成形中的应用能力，采用有限元方法对镍/铜包覆箔微通道在橡胶垫成形中的失效行为进行了预测。结果表明，该模型能较准确地反映出受尺寸效应影响的复合金属箔的成形极限。为确定复合金属箔的成形极限提供了新的科学依据。Thin-Walled StructuresCyclic response of innovative modular joints for modular buildings under bidirectional loadingJiajun Qin, Ping Tan, Fulin Zhou, Mengxiong Tang, Yafei Zhang, Jiajun Tandoi:10.1016/j.tws.2024.111889双向荷载作用下组合式建筑新型组合式节点的循环响应Based on their dual functions of loading-bearing and energy-dissipating, modular loading-bearing and energy-dissipating joints (MVJ) was used to vertically connect modules, particularly high-rise modular building applications. Fully bolted MVJs can be assembly and disassembly rapidly, and the modules can be recycled after disassembly. Quasi-static tests were conducted on two full-scale space specimens to evaluate seismic resistance properties of the MVJs. Owing to the critical function of MVJs in the buildings, the constant axial loading on the modular column and the vertical displacement on both double beams were implemented simultaneously to simulate the worst loading condition. Owing to the characteristics of double beams under vertical forces, and the requirements of simulation of boundary conditions, a double-beam hinged loading device was proposed. The experimental results demonstrate that the proposed MVJs exhibited great moment capacity. Accordingly, the ratios of the tested average ultimate moment capacity Mu to the designed ultimate moment capacity of double beams MPbeam were 0.828 for S1 and 0.995 for S2. Diagonal cracks occurred on the ends of MVC web for both S1 and S2, indicating that the proposed MVJs were crucial in both loading-bearing and energy-dissipating; the MVC web was used to dissipate energy. Because of the insufficient weld strength between the column and the ceiling beam, as well as the bidirectional cyclic displacement observed at both ends of double beams, the error in the average ultimate moment capacity between the tested and the predicted result is 17.08%. Analysis conducted on the ductility factor and inter-storey drift ratio demonstrated the feasibility of implementing MVJs in seismic regions.基于承重和消能的双重功能，模块化承重消能连接件（MVJ）被用于垂直连接模块，尤其是高层模块化建筑应用。全螺栓连接的 MVJ 可以快速组装和拆卸，拆卸后的模块可以回收利用。对两个全尺寸空间试样进行了准静力试验，以评估 MVJ 的抗震性能。由于 MVJ 在建筑中的重要作用，因此同时对模块柱施加恒定轴向荷载和对双梁施加垂直位移，以模拟最恶劣的荷载条件。根据双梁在垂直力作用下的特点和边界条件模拟的要求，提出了一种双梁铰接加载装置。实验结果表明，所提出的 MVJ 具有很强的弯矩承载能力。因此，S1 和 S2 的试验平均极限承载力 Mu 与双梁设计极限承载力 MPbeam 之比分别为 0.828 和 0.995。S1 和 S2 的 MVC 腹板端部都出现了对角线裂缝，这表明拟议的 MVJ 在承载和消能方面都很关键；MVC 腹板用于消能。由于支柱与顶梁之间的焊接强度不足，以及在双梁两端观察到的双向周期位移，测试结果与预测结果之间的平均极限弯矩承载力误差为 17.08%。对延性系数和层间漂移率的分析表明，在地震地区采用 MVJ 是可行的。Study on fire temperature fields of air-supported membrane structures considering thermal-fluid-solid coupling and boundary correctionGuojun Sun, Shuo Xiao, Xiushu Qu, Suduo Xue, Jiayong Wudoi:10.1016/j.tws.2024.111893考虑热-流-固耦合和边界校正的气支膜结构火灾温度场研究The study analyzed and compared the effects of thermal-fluid-solid coupling dynamic boundary conditions and traditional fixed-boundary conditions on the distribution of the temperature field under fires. The feasibility of simulating the temperature field distribution was confirmed by using thermal-fluid-solid coupling dynamic boundary conditions. Then, the traditional temperature field analysis methods were corrected by including a flow-based heat exchange coefficient, and the feasibility of this approach was also confirmed. The fire temperature field in a rectangular air-supported membrane structure was analyzed through parameterization. The fire temperature field model of the air-supported membrane structure was established using temperature field data fitting. Furthermore, the study explored the high-temperature material properties of P-type membranes and analyzed and compared the temperature field of the air-supported membrane structure with time-varying mechanical properties of the membrane material to that without time-varying properties.分析比较了热-流-固耦合动态边界条件和传统固定边界条件对火灾下温度场分布的影响。验证了采用热-流-固耦合动态边界条件模拟温度场分布的可行性。通过引入基于流动的换热系数，对传统的温度场分析方法进行了修正，并验证了该方法的可行性。通过参数化分析了矩形气支膜结构的火灾温度场。通过温度场数据拟合，建立了气支膜结构的火灾温度场模型。进一步研究了p型膜的高温材料性能，分析比较了具有时变膜材料力学性能的气支膜结构与无时变膜材料力学性能的气支膜结构的温度场。Prediction of vibration fatigue life of fiber reinforced composite thin plates with functionally graded coating under base random excitationCong Sun, Yao Yang, Hui Li, Hesong Xu, Feng Zhao, Zhuo Xu, Guowei Sun, Junxue Hou, He Lidoi:10.1016/j.tws.2024.111891基随机激励下功能梯度涂层纤维增强复合材料薄板振动疲劳寿命预测This study presents the prediction of the vibration fatigue life of fiber reinforced composite thin plates (FRCTPs) with the functionally graded coating (FGC) under base random excitation. A dynamic model of an FGC-FRCTP under such an excitation loading is developed using the first-order shear deformation theory, random vibration theory, complex modulus method, etc. The natural frequency, stress frequency response function, and stress power spectral density curves are solved by the Rayleigh-Ritz method and frequency domain random vibration analysis approach. Moreover, the random fatigue life of the FGC-FRCTPs is successfully predicted by the Dirlik, Bendat, and Tovo-Benasciutti distribution. Finally, the preparation approaches of the FGC and the coated specimens are introduced, and detailed experimental investigations are performed. It has been found that the prediction errors of fatigue life using the Bendat, Dirlik and Tovo-Benasciutti distributions are less than -14.6 %, which proves that the current model can be employed to evaluate the fatigue resistance of the FGC-FRCTPs. Also, the impact of key coating parameters on the vibration fatigue life of the studied coated structures is evaluated. To improve their fatigue resistance, it is advised to select a large coating area, coating thickness ratio, and functionally graded index with the coating position near the constrained edge of the FGC-FRCTPs.研究了基随机激励下功能梯度涂层纤维增强复合材料薄板的振动疲劳寿命预测。利用一阶剪切变形理论、随机振动理论、复模量法等建立了FGC-FRCTP在这种激励荷载作用下的动力模型。采用瑞利-里兹法和频域随机振动分析法求解了结构的固有频率、应力频响函数和应力功率谱密度曲线。此外，通过Dirlik、Bendat和Tovo-Benasciutti分布成功预测了fgc - frctp的随机疲劳寿命。最后介绍了FGC和涂层试样的制备方法，并进行了详细的实验研究。结果表明，利用Bendat、Dirlik和Tovo-Benasciutti分布对fgc - frctp疲劳寿命的预测误差小于- 14.6%，证明该模型可用于fgc - frctp的疲劳抗力评估。分析了涂层关键参数对涂层结构振动疲劳寿命的影响。为提高fgc - frctp的抗疲劳性能，建议选择较大的涂层面积、涂层厚度比和功能分级指标，且涂层位置靠近约束边缘。来源：复合材料力学仿真Composites FEM
