今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 3 篇International Journal of Solids and StructuresBuckling behavior modeling and prevention in hydro-pressing forming process of high strength metal tubesRuihua Chu, Xiao-Lei Cui, Jiuqiang He, Shijian Yuandoi:10.1016/j.ijsolstr.2025.113655 高强度金属管液压成形屈曲行为建模及预防Tube hydro-pressing is an advanced hydroforming process with less-loading requirements suitable for manufacturing tubular components of high strength metals such as dual-phase steels and titanium alloys. However, the thin-walled tube blank is prone to be buckling under bending moment and circumferential compressive stress during the hydro-pressing process. To prevent this defect, an ana lytical model of critical supporting pressure was firstly established based on energy theory during the corner filling process. The factors influencing critical supporting pressure were an alyzed to understand the characteristics in hydro-pressing for different tube materials. Subsequently, hydro-pressing experiments were conducted on two typical high strength metal tubes: DP590 dual-phase steel and TA18 titanium alloy. The experimental results verified the accuracy of the an alytical model and revealed the influence of the material on the critical supporting pressure. It is shown that the critical supporting pressure required for forming is positively related to strength coefficient (K) and negatively related to strain hardening exponent (n) and diameter-thickness ratio (d0/t) of the tube, but has little dependence on height-to-width ratio (h/w) of cross-section. For the two typical tubes, the critical supporting pressure required for forming was 4.11 MPa and 1.36 MPa, respectively. Stable corner filling can proceed without any buckling instability defects when the supporting pressure in the forming process is higher than the critical value mentioned above. These results provide theoretical support for the development and application of the tube hydro-pressing process.管材液压成形是一种载荷要求较低的先进液压成形工艺，适用于制造双相钢和钛合金等高强度金属的管材部件。然而，薄壁管坯在液压成形过程中，在弯矩和周向压应力作用下容易发生屈曲。为了防止这一缺陷，首先基于能量理论建立了角部充填过程中临界支撑压力的解析模型。分析了影响临界支撑压力的因素，了解了不同管材的液压特性。随后，对DP590双相钢和TA18钛合金两种典型高强度金属管进行了液压压制实验。实验结果验证了分析模型的准确性，揭示了材料对临界支撑压力的影响。结果表明：成形所需临界支撑压力与管材强度系数K呈正相关，与应变硬化指数n和管材径厚比d0/t呈负相关，而与管材截面高宽比h/w关系不大；两种典型管材成形所需的临界支撑压力分别为4.11 MPa和1.36 MPa。当成形过程中的支撑压力高于上述临界值时，可以进行稳定的边角填充，不存在屈曲失稳缺陷。研究结果为管材液压成形工艺的开发和应用提供了理论支持。Journal of the Mechanics and Physics of SolidsMacro- and Micro-Mechanical Perspectives on Creep-Fatigue Interaction in Type 316L Stainless SteelFan Wu, Yang Liu, Huayue Zhang, Christos Skamniotis, Umer Masood Chaudry, Gareth Douglas, Joe Kelleher, Andrew Wis bey, Mike Spindler, Marc Chevalier, Bo Chendoi:10.1016/j.jmps.2025.106353 316L型不锈钢蠕变-疲劳相互作用的宏观和微观力学观点Creep-fatigue of Type 316L stainless steel under asymmetric waveforms (specifically slow tension-fast compression, S-F, and fast tension-slow compression, F-S) has been understudied, despite its significant implications as demonstrated in this work. This study bridges macro- and micro-mechanical perspectives through a combined approach, involving high-temperature testing, scanning electron microscopy, X-ray computed tomography, neutron diffraction, and crystal plasticity modelling. Macro-mechanical tests revealed distinct deformation behaviours under S-F and F-S waveforms with and without a 1-hour tensile dwell at 550°C, with S-F reducing lifespan in both fatigue and creep-fatigue conditions. Post-mortem ana lyses revealed distinct fracture morphologies induced by tensile dwell, with creep-fatigue S-F specimen exhibiting more pronounced intergranular-dominant fracture and higher internal defect volume. It also exhibited the highest number fraction of medium-sized (10-40 μm) microcracks, which correlates with its shortest fatigue life and more creep damage accumulation. Higher grain-level deformation incompatibility was observed during tensile dwell in the S-F load waveform. Crystal plasticity modelling revealed that the higher tensile stress amplitudes during S-F loading stem from increased dislocation density, with average densities at peak tensile strain during the saturation cycle reaching 186 μm⁻² for S-F and 147 μm⁻² for F-S waveforms. These findings establish a strong link between macroscopic and microscopic behaviours under asymmetric loading, emphasising the potential of S-F waveforms for cost-effective creep-fatigue experiment design. Furthermore, for the asymmetric waveforms studied, creep-fatigue life assess ment using the ductility exhaustion method demonstrate greater accuracy than those based on the time fraction method.316L型不锈钢在不对称波形（特别是慢张-快压缩，S-F，和快张-慢压缩，F-S）下的蠕变疲劳还没有得到充分的研究，尽管它在这项工作中证明了它的重要意义。本研究通过结合高温测试、扫描电子显微镜、x射线计算机断层扫描、中子衍射和晶体塑性建模等方法，将宏观和微观力学观点联系起来。宏观力学测试显示，在550°C下，无论是否有1小时的拉伸停留，S-F和F-S波形下的变形行为都是明显的，S-F降低了疲劳和蠕变疲劳条件下的寿命。尸检分析揭示了拉伸驻留引起的明显断裂形态，蠕变疲劳S-F试样表现出更明显的晶间断裂和更高的内部缺陷体积。中等尺寸（10 ~ 40 μm）微裂纹数量最多，其疲劳寿命最短，蠕变损伤积累较多。在S-F载荷波形中，拉伸停留期间观察到较高的晶粒级变形不相容。晶体塑性模型显示，S-F加载过程中较高的拉伸应力振幅源于位错密度的增加，在饱和周期中，S-F波形的峰值拉伸应变平均密度达到186 μm⁻²，F-S波形的平均密度达到147 μm⁻²。这些发现建立了不对称载荷下宏观和微观行为之间的紧密联系，强调了S-F波形在经济有效的蠕变疲劳实验设计中的潜力。此外，对于所研究的非对称波形，使用延性耗尽法进行蠕变疲劳寿命评估比基于时间分数法的评估具有更高的准确性。International Journal of PlasticityUltra-low temperature mechanical response of VCoNi medium-entropy alloy with unprecedented high strength and ductilityTae Jin Jang, Min Young Sung, Gunjick Lee, Hahun Lee, Jun Ho Lee, Alireza Zargaran, Young-Kyun Kim, Zhiming Li, Young-Sang Na, Seok Su Sohndoi:10.1016/j.ijplas.2025.104473 具有空前高强度和高塑性的VCoNi中熵合金的超低温力学响应This work reports on the unprecedented high tensile strength and ductility of single-phase VCoNi medium-entropy alloys (MEAs) at liquid helium temperature (4.2 K) and reveals the effects of grain size on strength, strain-hardening capability, and discontinuous plastic flow (DPF) behavior at 4.2 K. The fine-grained VCoNi MEA with an average grain size of 2.2 μm exhibits exceptional yield strength of 1386 MPa and tensile stress of 1845 MPa at a high elongation of 43%. The Hall–Petch (H–P) relationship at 4.2 K for the VCoNi MEA was established for the first time, demonstrating that the yield strength enhancement with decreasing temperature primarily originates from a reduction in dislocation width, leading to an exceptionally high solid-solution strengthening contribution of 782 MPa. In addition to planar slip, nano-twinning and stacking faulting were activated at 4.2 K upon plastic deformation, contributing to a sustained strain-hardening capability. The restricted mobility of screw dislocations at 4.2 K suppresses dynamic recovery, facilitating dislocation proliferation and further enhancing strain hardening. In terms of DPF behavior, characterized by abrupt serrations in the stress-strain curves, fine-grained specimens exhibit more pronounced DPF due to the rapid accumulation of geometrically necessary dislocations. However, the maximum stress drop prior to plastic instability remains similar across all grain sizes, suggesting that dislocation density is the primary factor governing DPF behavior. These findings provide important insights into the development and mechanistic understanding of ultrastrong and ductile alloys for applications at extremely low temperatures.本文报道了单相VCoNi中熵合金（MEAs）在液氦温度（4.2 K）下具有前所未有的高拉伸强度和延展性，并揭示了晶粒尺寸对强度、应变硬化能力和不连续塑性流动（DPF）行为的影响。平均晶粒尺寸为2.2 μm的细晶VCoNi MEA屈服强度为1386 MPa，拉伸应力为1845 MPa，延伸率高达43%。首次建立了VCoNi MEA在4.2 K时的Hall-Petch （H-P）关系，表明随着温度的降低，屈服强度的增强主要来自位错宽度的减小，从而导致了极高的固溶强化贡献，达到782 MPa。除了平面滑移外，在4.2 K的塑性变形下，纳米孪晶和堆积断层也被激活，这有助于持续的应变硬化能力。4.2 K时螺位错的受限迁移抑制了动态恢复，促进了位错扩散，进一步增强了应变硬化。在DPF行为方面，其特征是应力-应变曲线上的突然锯齿，细晶试样由于几何上必要的位错的快速积累而表现出更明显的DPF。然而，塑性失稳前的最大应力降在所有晶粒尺寸中仍然相似，这表明位错密度是控制DPF行为的主要因素。这些发现为在极低温下应用的超强和延展性合金的开发和机理理解提供了重要的见解。Thin-Walled StructuresS mooth reconstruction of blade profile from data points and its characterizationKadir Kirandoi:10.1016/j.tws.2025.113846基于数据点的叶片型线平滑重构及其特征In the current paper, reconstruction and characterization procedures for the blade profile data points are comprehensively presented. For the reconstruction, a single C2-continuous fair Bezier curve fitting algorithm is developed. This algorithm is based on the nonlinear least squares fitting method and it performs fitting and fairing processes concurrently, which eliminates the need for post processing of the reconstructed blade profile. Thus, we are able to accurately represent large number of blade profile data points with maximum 14 control points of a Bezier curve. On the other hand, in the characterization procedure, the reconstructed blade profile camber line, radius distribution and fundamental design parameters (i.e., inlet metal, outlet metal and stagger angles, and chord length) are computed. The implementations and validations of the proposed procedures are completed with data points of various reference blade and airfoil profiles, and a worn aero-engine blade profile data points achieved via a coordinate measuring machine (CMM). The results have shown that the proposed procedures along with their algorithms are quite successful, practical, and powerful for the blade profile reconstruction and characterization. They have great potential as useful tools for the design, ana lysis, optimization, inspection, and manufacturing of the blades.在本文中，全面介绍了叶片轮廓数据点的重建和特征化程序。对于重建，开发了一种基于非线性最小二乘拟合方法的单 C2 连续光滑贝塞尔曲线拟合算法。该算法同时执行拟合和光顺过程，从而无需对重建的叶片轮廓进行后处理。因此，我们能够用最多 14 个贝塞尔曲线控制点准确表示大量叶片轮廓数据点。另一方面，在特征化程序中，计算了重建叶片轮廓的弯度线、半径分布和基本设计参数（即进口金属角、出口金属角和安装角以及弦长）。通过各种参考叶片和翼型轮廓的数据点以及通过坐标测量机（CMM）获得的磨损航空发动机叶片轮廓数据点，完成了所提出程序的实现和验证。结果表明，所提出的程序及其算法在叶片轮廓重建和特征描述方面非常成功、实用且强大。它们作为叶片设计、分析、优化、检测和制造的有用工具具有巨大潜力。Vibration an alysis of partially cracked thin orthotropic cylindrical shells with linearly and quadratically varying thickness: An ana lytical approachRahul Singh, Ankur Gupta, Nitin Kumar Jaindoi:10.1016/j.tws.2025.113939 线性和二次变厚正交各向异性薄圆柱壳部分开裂振动分析：一种解析方法This study presents an an alytical model for the free vibration an alysis of thin orthotropic cylindrical shells featuring linearly and quadratically varying thickness. The shell is assumed to have a length significantly greater than its other dimensions, and a s mall mid-span surface crack is considered to evaluate its impact on dynamic behaviour. The governing equations of motion are derived using classical shell theory and simplified using the Donnell–Mushtari–Vlasov (DMV) formulation to incorporate the effects of thickness variation. Crack-induced stiffness reduction is modelled using crack compliance coefficients based on the Line Spring Model (LS M), accounting for both axial and circumferential crack orientations. The influence of variable thickness on structural stiffness and vibration characteristics is explicitly addressed. A closed-form solution for simply supported and clamped boundary conditions is obtained via Hamilton’s principle and separation of variables. The an alytical results are validated through comparison with existing literature. A comprehensive parametric study is conducted to assess the effects of thickness gradients, crack size and position, and orthotropic material properties on the fundamental natural frequency.本文建立了具有线性和二次变化厚度的正交各向异性薄圆柱壳的自由振动分析模型。假设壳的长度明显大于其其他尺寸，并考虑一个小的跨中表面裂纹来评估其对动力性能的影响。利用经典壳体理论推导了运动控制方程，并利用Donnell-Mushtari-Vlasov （DMV）公式进行了简化，以考虑厚度变化的影响。采用基于线弹簧模型（LS M）的裂纹柔度系数，考虑轴向和周向裂纹方向，对裂纹诱导的刚度降低进行建模。明确讨论了变厚度对结构刚度和振动特性的影响。利用Hamilton原理和分离变量法，得到了简支固支边界条件的封闭解。通过与已有文献的比较，验证了分析结果。对厚度梯度、裂纹尺寸和位置以及正交各向异性材料特性对基频的影响进行了综合参数化研究。Experimental and Numerical Investigation of Vibration Characteristics of X-Frame CFRP Sandwich PlatesMin Tang, Longjun Chen, Weimin Jiang, Zhikang Liu, Jiayi Liu, Wei Huangdoi:10.1016/j.tws.2025.113942x -框架CFRP夹芯板振动特性试验与数值研究The vibration performance of the X-frame carbon fiber reinforced polymer (CFRP) sandwich plates was studied by experiments and simulations in this paper. The research focused on the influences of foam filling, relative density (RD) and designed parameters of the core on the modal characteristic and surface mean quadratic velocity of the plates. Firstly, the vibration modals and mean quadratic velocity of X-frame sandwich plates with or without foam-filled were measured in vacuum as well as underwater through experiments. Then, numerical simulation ana lysis was carried out, and the results by numerical simulation an alysis were highly consistent with the experimental results. Finally, the vibration performance of X-frame sandwich plates with different parameters was researched by the validated numerical simulation ana lysis. The results of experiments indicated that filling low-density foam into the core could increase the natural frequencies slightly and reduce the mean quadratic velocity at the natural frequencies of the plates. The low-density foam played a role in peak shaving. Improving the relative density of the core increased the natural frequencies significantly and reduced the overall mean quadratic velocity of the plates. The influence of parameter variations on vibration performance was discussed based on the favorable agreement observed between the results by experiment and simulation. The simulation results showed that the 45° X-frame sandwich plate had the s mallest surface mean quadratic velocity compared with the other three designed angles including 40°, 55°, and 70° when the relative density of the core was same.通过实验和仿真研究了x -框架碳纤维增强聚合物（CFRP）夹层板的振动性能。研究了泡沫填充、相对密度和芯材设计参数对板的模态特性和表面平均二次速度的影响。首先，通过实验测量了x -框架夹层板在真空和水下的振动模态和平均二次速度。然后进行数值模拟分析，数值模拟分析结果与实验结果高度吻合。最后，通过验证的数值模拟分析，研究了不同参数下x -框架夹层板的振动性能。实验结果表明，在芯内填充低密度泡沫可以略微提高板的固有频率，降低板在固有频率处的平均二次速度。低密度泡沫起到了剃峰的作用。提高堆芯的相对密度显著提高了固有频率，降低了整体平均二次速度。在实验结果与仿真结果吻合良好的基础上，讨论了参数变化对振动性能的影响。仿真结果表明，在堆芯相对密度相同的情况下，45°x -框架夹心板的表面平均二次速度比40°、55°和70°夹心板设计角度最小。来源：复合材料力学仿真Composites FEM
