【新文速递】2023年12月15日复合材料SCI期刊最新文章_ACT_Mechanical_Additive_System_MAGNET_振动_复合材料_化学_航空_航天_轨道交通_电子_增材_BIM_理论_材料_多尺度

【新文速递】2023年12月20日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresVisual investigation of static contact conditions at bolted jointsGuan-Sian Li, Yum Ji Chandoi:10.1016/j.ijsolstr.2023.112621螺栓连接处静态接触条件的目测调查Accurate numerical models of physical systems are vital in engineering applications, and those for single components are generally accurate. However, there are significant errors in modelling the dynamics of bolted joints, which is a key source of friction in real-life systems, because existing experimental techniques are still far from offering sufficient understanding of the contact conditions of bolted joints. In the current study, static contact conditions of bolted joints are investigated with at least one component in the assembly being transparent. A novel visual identification method is proposed to (i) measure the clearance between plates in the vicinity of bolted joints and (ii) identify the contact conditions in receding contacts by applying a paste (known as Engineer’s blue) to the contact surface. The paste is thinner than most media applied in previous studies. Clearance results obtained by visual inspection are checked against micrometer profile tracing, and the contact regions predicted by the method are used to validate simulation results obtained from two contact mechanics algorithms. Difference between simulation and experiment is as low as 9% in terms of contact region diameters. Last but not least, the reproducibility of the method has been demonstrated, especially if the clearance is in the range of 2 to 5 μm.精确的物理系统数值模型在工程应用中至关重要，单个组件的数值模型一般都很精确。然而，由于现有的实验技术还远未充分了解螺栓连接的接触条件，因此在模拟实际系统中摩擦的主要来源--螺栓连接的动态时，存在很大的误差。在当前的研究中，我们研究了螺栓连接的静态接触条件，其中至少有一个组件是透明的。研究提出了一种新颖的视觉识别方法：(i) 测量螺栓连接处附近板间的间隙；(ii) 通过在接触面上涂抹浆糊（称为工程师蓝）来识别后退接触中的接触状况。这种浆糊比以往研究中使用的大多数介质都要稀。通过目视检查获得的间隙结果与千分尺轮廓跟踪结果进行核对，该方法预测的接触区域用于验证两种接触力学算法获得的模拟结果。就接触区域直径而言，模拟和实验之间的差异低至 9%。最后但并非最不重要的一点是，该方法的可重复性得到了证明，尤其是当间隙在 2 至 5 μm 范围内时。Journal of the Mechanics and Physics of SolidsInitiation of motility on a compliant substrateJocelyn Étienne, Pierre Rechodoi:10.1016/j.jmps.2023.105526在顺应性基质上启动运动The conditions under which biological cells switch from a static to a motile state are fundamental to the understanding of many healthy and pathological processes. In this paper, we consider a cell constrained to move along a one-dimensional track. We show that even in the presence of a fully symmetric protrusive activity at the cell edges, such a spontaneous transition can result from a feedback of the deformation of an elastic substrate on the cell traction forces. The loss of symmetry of the traction forces leading to the cell propulsion is rooted in the fact that the surface loading follows the substrate deformation, leading the cell to surf its own wake. The bifurcation between the static and motile states is characterized analytically and, considering the measurements performed on two cell types, we show that such an instability can realistically occur on soft in vivo substrates.生物细胞从静止状态转为运动状态的条件是了解许多健康和病理过程的基础。在本文中，我们考虑了细胞受限沿一维轨道运动的情况。我们的研究表明，即使细胞边缘存在完全对称的突起活动，弹性基质的变形对细胞牵引力的反馈也会导致这种自发转换。导致细胞推进的牵引力失去对称性的根本原因在于，表面载荷随基底变形而变化，从而导致细胞自行冲浪。我们对静态和运动状态之间的分叉进行了分析，并通过对两种细胞类型的测量结果表明，这种不稳定性可能真实地发生在柔软的活体基底上。Mechanics of MaterialsMechanical behaviour of ductile polymer cellular model structures manufactured by FDMJacopo Agnelli, Claudia Pagano, Irene Fassi, Laura Treccani, Fabio Bignotti, Francesco Baldidoi:10.1016/j.mechmat.2023.104882用 FDM 制造的韧性聚合物蜂窝模型结构的力学性能In this work, Acrylonitrile-Butadiene-Styrene model structures were manufactured by FDM, and their mechanical behaviour investigated under compression, both at small and at large strains. The structure design strategy adopted, based on the use of circular cross-section beam-like elements formed under controlled conditions, led to obtain open-celled structures (with a porosity degree of ≈65%) composed of unit cells with different shapes and dimensions assembled to form regularly repeating patterns. The stress–strain behaviour, from cube- and prism-shaped specimens with different sizes and loaded along different directions, was discussed in the light of the outcomes from (i) cyclic compression experiments and (ii) morphological analyses of cryogenic fracture surfaces of specimens compressed at high strain levels. The response along the 3D-stacking direction was traced back to the elastic–plastic case, with non-recoverable strain starting to accumulate between 3% and 5% strain and structure densification starting below 20%. The specimen size effects turned out to be little pronounced. Slightly higher levels of stiffness and strength were measured for the largest cube. This result was discussed on the basis of the peculiar morphology of the structure examined.在这项工作中，通过 FDM 制造了丙烯腈-丁二烯-苯乙烯模型结构，并研究了其在小应变和大应变压缩条件下的机械性能。所采用的结构设计策略基于使用在受控条件下形成的圆形截面梁状元件，从而获得了开孔结构（孔隙度约为65%），由不同形状和尺寸的单元格组成，并组合成有规律的重复图案。根据（i）循环压缩实验和（ii）高应变水平压缩试样低温断裂表面形态分析的结果，讨论了不同尺寸和沿不同方向加载的立方体和棱柱形试样的应力应变行为。沿三维堆叠方向的响应可追溯到弹塑性情况，不可恢复应变在 3% 至 5% 应变之间开始累积，结构致密化在 20% 以下开始。试样尺寸的影响并不明显。最大立方体的刚度和强度水平略高。对这一结果的讨论是基于所研究结构的特殊形态。International Journal of PlasticityCreep-fatigue life prediction of notched structure after an advanced surface strengthening treatment in a nickel-based superalloy at 650°CKai-Shang Li, Shu-Lei Yao, Lv-Yi Cheng, Run-Zi Wang, Li Sun, Hang-Hang Gu, Ji Wang, Ti-Wen Lu, Cheng-Cheng Zhang, Xian-Cheng Zhang, Shan-Tung Tudoi:10.1016/j.ijplas.2023.103861镍基超合金在 650°C 高温下经过高级表面强化处理后缺口结构的蠕变疲劳寿命预测The elucidation of creep-fatigue damage mechanisms is still controversial for high-temperature structures after surface strengthening treatments, which serves as a critical foundation for the development of an accurate life prediction method. In this work, a numerical procedure is constructed for the prediction of creep-fatigue life improvement, where a dual-scale modeling approach is proposed to integrate important strengthening factors and microstructure features. The macro-scale finite element (FE) simulation aims to investigate the cyclic deformation behavior in a notched structure by using a viscoplastic constitutive model. The initial stress field is predetermined based on the experimental residual stress. The micro-scale FE analysis is employed to investigate the local damage evolution occurring at the notched root by combining size-dependent crystal plasticity with grain boundary cavity model. The cycle-by-cycle deformation histories are extracted from the macro-scale FE model and subsequently are utilized as boundary conditions in the micro-scale FE one. From the experimental perspective, the submerged micro-abrasive waterjet peening (SMA-WJP) process is carried out for creep-fatigue life improvement of the notched structure. Results shows that the notched structure treated by the SMA-WJP process forms an obvious plastic layer with the depth of 20 μm and residual stress with the maximum value of -926 MPa. The predicted numbers of cycles to crack initiation agree with the creep-fatigue experimental ones before and after SMA-WJP. In detail, the surface residual stress and plastic layer are unable to suppress the cavity nucleation on the grain boundaries of internal material. As a consequence, the creep-fatigue life improvement is diminished as the hold time increases, which can be accurately predicted by the developed numerical procedure.对于表面强化处理后的高温结构，蠕变疲劳损伤机理的阐明仍存在争议，这也是开发精确寿命预测方法的重要基础。本研究构建了蠕变疲劳寿命提高预测的数值程序，提出了一种双尺度建模方法，以整合重要的强化因素和微观结构特征。宏观尺度的有限元（FE）模拟旨在利用粘塑性组成模型研究缺口结构的循环变形行为。初始应力场是根据实验残余应力预先确定的。采用微尺度有限元分析，结合尺寸相关晶体塑性和晶界空腔模型，研究缺口根部发生的局部损伤演变。从宏观尺度 FE 模型中提取逐周期变形历史，然后将其作为微观尺度 FE 模型的边界条件。从实验角度来看，采用浸没式微磨料水刀强化（SMA-WJP）工艺来提高缺口结构的蠕变疲劳寿命。结果表明，经 SMA-WJP 工艺处理的缺口结构形成了深度为 20 μm 的明显塑性层，残余应力的最大值为 -926 MPa。预测的裂纹萌发循环次数与 SMA-WJP 前后的蠕变疲劳实验次数一致。具体来说，表面残余应力和塑性层无法抑制内部材料晶界上的空洞成核。因此，随着保持时间的增加，蠕变疲劳寿命的提高幅度会减小，这一点可以通过所开发的数值程序准确预测。Thin-Walled StructuresLaser beam oscillation welding for fatigue properties enhancement of tailor-welded blanksHana ŠEBESTOVÁ, Michal JAMBOR, Petr HORNÍK, Jan NOVOTNÝ, Libor MRŇAdoi:10.1016/j.tws.2023.111506激光束振荡焊接用于提高定制焊接坯料的疲劳性能Dissimilar thickness laser welded tailored blanks of two low-alloyed carbon steel grades were fabricated. Laser welds made without beam oscillation exhibited serious root undercuts. Although these notches did not degrade the tensile strength, they were detrimental to the fatigue lifetime of a weld joint. Therefore, laser welds with three different beam oscillation modes to modify the root were examined. Application of beam oscillation improved fatigue properties in all tested cases. The best results were achieved with line oscillation, even though this mode did not suppress weld root notches, suggesting other factors, besides joint geometry, contributing to the resulting fatigue properties.用两种低合金碳钢制造了厚度不同的激光焊接定制坯件。在没有光束振荡的情况下进行的激光焊接会出现严重的根部缺口。虽然这些缺口不会降低抗拉强度，但对焊点的疲劳寿命不利。因此，我们研究了采用三种不同的光束振荡模式来改变根部的激光焊接。在所有测试案例中，光束振荡都改善了疲劳性能。直线振荡的效果最好，尽管这种模式并不能抑制焊缝根部的缺口，这表明除了焊点几何形状之外，还有其他因素也会影响所产生的疲劳性能。来源：复合材料力学仿真Composites FEM

【新文速递】2023年12月15日复合材料SCI期刊最新文章

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【新文速递】2023年12月20日固体力学SCI期刊最新文章