【新文速递】2024年8月14日固体力学SCI期刊最新文章_ACT_Mechanical_Additive_Optical_System_断裂_复合材料_非线性_隐身_光学_增材_焊接_裂纹_理论_材料_分子动力学

【新文速递】2024年8月18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 StructuresInfluence of elasto-plastic behaviour of thin films on circular buckling structuresK. Meng, G. Parry, M.A. Hurier, C. Tromas, C. Coupeaudoi:10.1016/j.ijsolstr.2024.113032薄膜弹塑性对圆形屈曲结构的影响We report on circular buckles experimentally observed by optical and atomic force microscopy on gold ductile thin films deposited by physical vapor deposition on silicon wafers. It is shown that, whatever the radius blister dimensions, their maximum deflections are higher than those expected by the elastic theory. It suggests that plastic events may take place in the film, impacting on the blister morphology as a result. Based on nanoindentation experiments carried out on our gold films, a proper plastic hardening law has been determined by calculations using the finite elements method. The influence of this elasto-plastic behavior on the buckled circular profiles has been then numerically studied, compared to the experimental observations and discussed.本文报道了用光学和原子力显微镜在物理气相沉积在硅片上的金延展性薄膜上实验观察到的圆形屈曲。结果表明，无论气泡半径大小如何，其最大挠度都高于弹性理论所期望的挠度。这表明塑料事件可能在薄膜中发生，从而影响水疱形态。在对金薄膜进行纳米压痕实验的基础上，采用有限元法计算确定了合适的塑性硬化规律。然后对这种弹塑性行为对屈曲圆形型材的影响进行了数值研究，并与实验结果进行了比较和讨论。Journal of the Mechanics and Physics of SolidsA regularized variational mechanics theory for modeling the evolution of brittle crack networks in composite materials with sharp interfacesKaushik Vijaykumar, Benjamin E. Grossman-Ponemon, Yang Wan, Pooya Yousefi, Christopher J. Larsen, Haneesh Kesaridoi:10.1016/j.jmps.2024.105772具有尖锐界面的复合材料脆性裂纹网络演化的正则变分力学理论In the design of structural materials, there is traditionally a tradeoff between achieving high strength and achieving high toughness. Nature offers creative solutions to this problem in the form of structural biomaterials (SBs), intelligent arrangements of mineral and organic phases which possess greater strength and toughness than the constituents. The micro-architecture of SBs like nacre and sea sponge spicules are characterized by weak organic interfaces between brittle mineral phases. To better understand the toughening mechanisms in SBs requires simulation techniques which can resolve arbitrary interface and bulk fracture patterns.In this work, we present a modified regularization of Variational Fracture Theory (VFT) that allows for simulation of fracture in materials and structures with weak interfaces. The core of our approach is widen the weak interfaces on a length scale proportional to that of the diffuse damage field, and assign a reduced fracture toughness therein. We show that in 2D the modified regularized functionals Γ-converge to that for sharp cracks. The resulting thin weak interfaces have fracture toughness which depends on the bulk material fracture toughness, the widened interface fracture toughness, and the widened interface length scale. We next apply our modified regularization within a computer implementation of regularized VFT, which we term RVFTI. We assess the performance of RVFTI in 2D by reproducing the effective interface fracture toughness predicted by the Γ-convergence theory and simulating crack trapping at a bi-material interface. We then use RVFTI to study toughening in SB-inspired microarchitectures, namely layered materials and materials with wavy interfaces.在结构材料的设计中，传统上需要在实现高强度和高韧性之间做出权衡。大自然以结构生物材料（SBs）的形式为这一问题提供了创造性的解决方案，SBs 是矿物和有机相的智能排列，具有比成分更高的强度和韧性。珍珠质和海绵体等 SB 的微观结构特点是脆性矿物相之间的有机界面较弱。要更好地了解 SB 的增韧机制，就需要能解析任意界面和整体断裂模式的模拟技术。在这项工作中，我们提出了一种修正的变分断裂理论（VFT）正则化方法，可以模拟具有弱界面的材料和结构的断裂。我们方法的核心是在与弥散损伤场成正比的长度尺度上拓宽弱界面，并在其中赋予降低的断裂韧性。我们的研究表明，在二维情况下，修正后的正则化函数与尖锐裂缝的正则化函数Γ-趋同。由此产生的薄弱界面的断裂韧性取决于块体材料断裂韧性、加宽界面断裂韧性和加宽界面长度尺度。接下来，我们在正则化 VFT 的计算机实现中应用了修改后的正则化，我们称之为 RVFTI。我们通过再现Γ-收敛理论预测的有效界面断裂韧性并模拟双材料界面的裂纹捕获，评估了 RVFTI 在二维中的性能。然后，我们使用 RVFTI 研究 SB 启发的微结构（即层状材料和具有波浪形界面的材料）中的增韧问题。Mechanics of MaterialsAn analytical and experimental investigation into overall dissipation of flexural mode in a periodically damped beamSouryadeep Biswas, Arnab Banerjee, Kamal K. Beradoi:10.1016/j.mechmat.2024.105113周期阻尼梁挠曲模态总耗散的分析与实验研究This study presents an innovative analytical model to estimate the overall energy dissipation in damped Euler–Bernoulli beams with uniform and non-uniform (stepped) cross-sections. The novelty lies in proposing a closed-form expression for an envelope function that closely matches the energy dissipation profile obtained from the time-domain response. Importantly, the study unveils a non-intuitive finding, which states that the rate of energy decay predominantly depends on the configuration (orientation) of the stepped beam. Both strain rate-dependent viscous damping and velocity-dependent viscous damping components are considered in the governing equations. An analytical formulation is developed to obtain the wave-number-dependent damped frequencies and damping ratios using the free-wave approach. The coefficient of energy decay, governing the envelope function, is expressed in terms of the damping ratios, natural frequencies, mode participation factors, and the ratio of flexural rigidities. Moreover, this study presents the experimental validation of the analytical formulation by estimating the settling times from free vibration tests on 3D-printed stepped beams with different configurations and further quantifies the damping coefficients of the stepped beam by applying the nonlinear least squares method to fit the peaks in the experimentally acquired acceleration response. The close agreement between analytical and experimental results establishes the accuracy and applicability of the proposed model for transient vibration mitigation.本文提出了一种新颖的分析模型来估计均匀截面和非均匀截面(阶梯)阻尼欧拉-伯努利梁的总能量耗散。新颖之处在于提出了一个封闭形式的包络函数表达式，该表达式与从时域响应中获得的能量耗散曲线密切匹配。重要的是，这项研究揭示了一个非直觉的发现，即能量衰减的速率主要取决于阶梯梁的结构(方向)。控制方程中考虑了应变率相关的粘性阻尼分量和速度相关的粘性阻尼分量。利用自由波法推导出了与波数相关的阻尼频率和阻尼比的解析公式。控制包络函数的能量衰减系数用阻尼比、固有频率、模态参与系数和弯曲刚度比来表示。此外，通过对不同构型的3d打印阶梯梁进行自由振动试验，估计其沉降时间，对解析公式进行了实验验证，并利用非线性最小二乘法对实验得到的加速度响应峰进行拟合，进一步量化了阶梯梁的阻尼系数。分析结果与实验结果吻合较好，证明了该模型对瞬态振动抑制的准确性和适用性。International Journal of PlasticityUncovering all possible dislocation locks in face-centered cubic materialsD. Bajaj, D.L. Chendoi:10.1016/j.ijplas.2024.104101 揭示面心立方材料中所有可能的位错锁Dislocation reactions and locks play an important role in the plastic deformation and mechanical behavior of crystalline materials. Various types of dislocation locks in face-centered cubic (FCC) materials have been reported in the literature pertaining to material-specific molecular-dynamic simulations and high-resolution transmission electron microscopy observations. However, it is unknown how many dislocation locks are possible, and how immobile all the dislocation locks are, with respect to each other. Here we present a discrete mathematics-based approach to reveal all possible dislocation locks in the FCC crystal structure. Totally eight types of dislocation locks are uncovered, resulting from all possible reactions of mobile/glissile (namely, perfect and Shockley partial) dislocations with (a) non-coplanar Burgers vectors which reside on two slip planes intersecting at both obtuse and acute angles and (b) coplanar Burgers vectors. We redefine the degree of dislocation lock immobility based on misorientations between non-close-packed lock planes and close-packed {111} slip planes. The subsequently derived sequences for the dislocation lock immobility and formation tendency are rationalized by the reported experimental and dislocation-dynamics simulation results.位错反应和锁在晶体材料的塑性变形和力学行为中起着重要的作用。面心立方(FCC)材料中各种类型的位错锁已经在与材料特异性分子动力学模拟和高分辨率透射电子显微镜观察相关的文献中得到了报道。然而，目前尚不清楚可能有多少位错锁，以及所有位错锁相对于彼此的不动程度。在这里，我们提出了一种基于离散数学的方法来揭示FCC晶体结构中所有可能的位错锁。共有八种类型的位错锁被发现，这是由所有可能的移动/滑动位错(即完全位错和肖克利部分位错)与(a)位于以钝角和锐角相交的两个滑移面上的非共面Burgers矢量和(b)共面Burgers矢量的反应造成的。我们基于非密实锁面和密实{111}滑移面之间的取向偏差重新定义了位错锁不动的程度。本文的实验结果和位错动力学模拟结果使推导出的位错锁不动性和形成倾向的序列更为合理。Thin-Walled StructuresA methodology for evaluating damage in thin-walled cylindrical shells using bounded ultrasonic beam scatteringJiangcheng Cai, Mingxi Dengdoi:10.1016/j.tws.2024.112352用有界超声波束散射评估薄壁圆柱壳损伤的方法This paper introduces an ultrasonic detection methodology specifically designed to assess damage in thin-walled cylindrical shells, which crucially relies on the interaction between a bounded ultrasonic beam and a thin-walled cylindrical shell immersed in fluid, considering both water-filled and air-filled cavities. Initially, we derive the scattered sound field expression for a bounded ultrasonic beam obliquely striking the shell. Subsequently, through finite element simulations and experimental verification, we observe that when the incident bounded beam is emitted at the critical angles defined in this study, early damage significantly enhances the received sound pressure amplitude detected by a symmetrically positioned receiver. Notably, a mere 5% decrease in the shell's elastic modulus leads to a notable 233.69% increase in the area under the amplitude-frequency curve of the received sound pressure for water-filled cavities and a remarkable 642.85% surge in area for air-filled cavities. Experimental data further validates the sensitivity of this method towards varying corrosion damage states. This approach combines the reliability of linear ultrasonic methods with the enhanced sensitivity of nonlinear ultrasonic techniques, offering a significant advancement over traditional ultrasonic detection methods for inspecting cylindrical shells. The proposed assessment method holds immense potential in providing novel insights for inspecting cylindrical shells in practical applications.本文介绍了一种专门用于评估薄壁圆柱壳损伤的超声检测方法，该方法主要依赖于有界超声束与浸入流体中的薄壁圆柱壳之间的相互作用，同时考虑了充水腔和充气腔。首先推导了有界超声波束斜击壳时的散射声场表达式。随后，通过有限元模拟和实验验证，我们观察到，当入射有界光束以本文定义的临界角发射时，早期损伤显著增强了对称定位接收机检测到的接收声压幅值。值得注意的是，当壳的弹性模量减小5%时，充水空腔的声压幅频曲线下面积显著增大233.69%，充气空腔的声压幅频曲线下面积显著增大642.85%。实验数据进一步验证了该方法对不同腐蚀损伤状态的敏感性。该方法结合了线性超声方法的可靠性和非线性超声技术的增强灵敏度，与传统的超声检测方法相比，在检测圆柱壳方面有了显著的进步。所提出的评估方法在实际应用中为检测圆柱壳提供新的见解方面具有巨大的潜力。来源：复合材料力学仿真Composites FEM