【新文速递】2024年10月21日固体力学SCI期刊最新文章_ACT_Mechanical_Additive_Optical_HPC_Deform_振动_非线性_化学_拓扑优化_光学_通用_航空_航天_电子_增材_ECAD_理论

【新文速递】2024年10月23日固体力学SCI期刊最新文章

今日更新：Journal of the Mechanics and Physics of Solids 1 篇，Thin-Walled Structures 5 篇Journal of the Mechanics and Physics of SolidsElastoplastic plate shakes down under repeated impulsive loadingsZengshen Yue, Bingyang Li, Xin Wang, Zhen Li, Rui Zhang, Pengfei Wang, Li Cheng, Tian Jian Ludoi:10.1016/j.jmps.2024.105918弹塑性板在反复的脉冲载荷作用下会发生振动When subjected to repeated dynamic impacts at identical load level, a metallic monolithic beam/plate may reach a stable state wherein measurable deformation ceases (i.e., shakedown in elastic state) after undergoing a sequence of elastoplastic deformations, which has been termed as “pseudo-shakedown” (P-S) (Jones, 1973, Shen and Jones, 1992). While the response of a single beam/plate under repeated low-velocity impacts has been thoroughly studied, its dynamic behavior under high-velocity impacts, such as explosive or alternating impulsive loads, is difficult to measure experimentally, due mainly to high costs and setup challenges. In the current study, the method of metallic foam projectile impact was employed to produce repeated impulsive loadings on a fully-clamped elastoplastic monolithic plate made of L907A (a Chinese standard shipbuilding steel). Its dynamic responses, including mid-point deflection versus time histories, final deflections, and deformation modes after each impact, were systematically measured. The phenomenon of dynamic shakedown was observed. To further explore this phenomenon, the method of finite elements (FE) was employed to simulate the repeated impulsive impact test, and its prediction accuracy was validated against experimental results. Unlike an elastoplastic (e.g., steel) monolithic plate subjected to repeated low-velocity impacts, which exhibits zero plastic energy dissipation in the P-S (pseudo-shakedown) state, the same plate under repeated high-velocity impacts shows a small level of plastic energy dissipation in the P-S state, mainly due to more extreme loading conditions. The initial impact momentum, yield strength, and tangent modulus of the material the plate is made of significantly affect both the stable deflection in the P-S state and the number of impacts needed to reach it, while the elastic modulus has limited influence. A modified dimensionless impulse loading number, accounting for the strain-hardening effect, is proposed. An approximately linear relationship between stable deflection in the P-S state and impulsive loading is found in dimensionless form.当金属整体梁/板在相同的荷载水平上受到反复的动力冲击时，在经历了一系列弹塑性变形后，金属整体梁/板可能达到稳定状态，其中可测量的变形停止（即弹性状态下的安定），这种变形被称为“伪安定”（P-S）（Jones, 1973； Shen和Jones， 1992）。虽然单梁/板在重复低速冲击下的响应已经得到了深入的研究，但由于高成本和设置挑战，其在高速冲击（如爆炸或交变脉冲载荷）下的动态行为难以通过实验测量。在本研究中，采用金属泡沫弹丸冲击的方法，对L907A（中国标准造船钢）全夹紧弹塑性整体板产生重复脉冲载荷。系统地测量了其动态响应，包括中点挠度与时间历史、最终挠度和每次撞击后的变形模式。观察到动态安定现象。为了进一步探讨这一现象，采用有限元方法对重复脉冲冲击试验进行了模拟，并与试验结果对比验证了预测的准确性。弹塑性（如钢）整体板在重复低速冲击下，在P-S（伪安定）状态下表现为零塑性能量耗散，而同一块板在重复高速冲击下，在P-S状态下表现出很小的塑性能量耗散，这主要是由于更极端的加载条件。板材的初始冲击动量、屈服强度和切线模量对P-S状态下的稳定挠度和达到稳定挠度所需的撞击次数都有显著影响，而弹性模量的影响有限。提出了考虑应变硬化效应的改进无量纲冲击载荷数。在无量纲形式下，发现P-S状态下的稳定挠度与脉冲载荷之间存在近似线性关系。Thin-Walled StructuresStudy on the buckling behavior of aluminum alloy sheets - before and after repaired with composite patchesXin Li, Anbiao Zhong, Jiale Zhang, Weilin Dong, Ruoqin Xiong, Heng Zhang, Xiaoliang Geng, Lei Huang, Jun Liudoi:10.1016/j.tws.2024.112614复合修补前后铝合金板的屈曲行为研究In this paper, the compressive buckling behavior of aluminum alloy plates with an elliptical hole of various sizes is investigated. In order to improve the stability of these thin plates, T700/QY8911 composite laminate is used as a patch to repair the hole. The study included an analysis of the critical and post-critical behaviour using experimental and numerical methods. Experiments focus on buckling loads, post-buckling behavior and the relationship between sizes of holes and buckling load. Meanwhile, the buckling load and buckling mode are determined by finite element analysis, using linear analysis of eigenvalue problems modes, and then, the nonlinear analysis of structures with initiated geometrically imperfection is carried out, studying its post-buckling behavior, damage behavior and transfer of load. The results show that the buckling load of the open-hole specimen is related to size of opening. The existence of patch has a significant influence on stress distribution, and the buckling capability of repaired specimens is noticeably improved to the plate without a hole. And the compression experimental results are consistent with the numerical results, revealing that the developed finite element model of the structure is correct.本文研究了不同尺寸椭圆孔铝合金板的压缩屈曲行为。为了提高这些薄板的稳定性，采用T700/QY8911复合层压板作为补片修补孔洞。该研究包括使用实验和数值方法对临界和后临界行为进行分析。实验重点研究了屈曲载荷、后屈曲行为以及孔洞尺寸与屈曲载荷的关系。同时，通过有限元分析，利用特征值问题模态的线性分析，确定了结构的屈曲载荷和屈曲模态，并对具有初始几何缺陷的结构进行了非线性分析，研究了结构的失稳后行为、损伤行为和载荷传递。结果表明：开孔试件的屈曲载荷与开孔尺寸有关。补片的存在对应力分布有显著影响，修复试件的屈曲能力明显优于无孔板。压缩实验结果与数值计算结果吻合较好，表明所建立的结构有限元模型是正确的。Peridynamics model of torsion-warping: Application to lattice beam structuresSajal, Pranesh Roydoi:10.1016/j.tws.2024.112603 扭转翘曲的周动力学模型：在点阵梁结构中的应用This paper presents a finite deformation beam model based on Simo-Reissner theory in peridynamics (PD) framework to deal with torsion induced warping deformation. Seven degrees of freedom, viz. three translational, three rotational, and one warping amplitude are considered at each material point. The governing equations of the beam are obtained by employing global balance of linear and angular momenta in conjunction with Simo's assumption on the deformation field. The relation between PD resultant force, moment, bi-moment, and bi-shear states with their classical counterparts is established using the constitutive correspondence method. Numerical implementation strategy is furnished for both quasi-static and dynamic cases. The solution for quasi-static load is obtained through the Newton-Raphson method. The proposed model is validated against finite element solutions considering cantilever beam and lattice structures. Quasi-static deformation responses of 3×3×3 octet and single unit compression-torsion lattice structures are presented further to demonstrate the effectiveness of proposed beam model. A new bond breaking criterion is proposed based on critical stretch, critical relative rotation, and critical relative warping amplitude and failure of the compression-torsion lattice structures under compressive load is simulated. The Newmark-beta method is utilized to solve the governing equations for dynamic loading. Numerical simulations include dynamic analysis of octet and compression-torsion lattice structures.本文提出了一种基于Simo-Reissner理论的近场动力学（PD）框架有限变形梁模型，用于处理由扭转引起的弯曲变形。在每个材料点处考虑了三个平移、三个旋转和一个弯曲幅度的七个自由度。通过采用线性和角动量全球平衡以及Simo关于变形场的假设，获得了梁的控制方程。利用本构对应方法建立了PD结果力、矩、二矩和二剪状态与它们的经典对应物之间的联系。为静力和动力情况提供了数值实现策略。通过牛顿-拉夫森方法获得了静力载荷的解。将该模型与考虑悬臂梁和网格结构的有限元解进行了验证。进一步展示了3×3×3八面体和单单元压缩-扭转网格结构的静力变形响应，以示例该梁模型的有效性。提出了一种基于临界伸长、临界相对转动和临界相对弯曲振幅的新的断裂准则，并通过Newmark-beta方法模拟了压缩载荷下压缩-扭转网格结构的失效。数值模拟包括八面体和压缩-扭转网格结构的动态分析。A novel machine learning framework for impact force prediction of foam-filled multi-layer lattice composite structuresJiye Chen, Yufeng Zhao, Hai Fang, Zhixiong Zhang, Zheheng Chen, Wangwang Hedoi:10.1016/j.tws.2024.112607一种用于泡沫填充多层晶格复合材料结构冲击力预测的机器学习框架Numerical simulations can provide valuable insights for the optimization of design and operational management; however, they are often impractical and computationally intensive. Machine learning methods are appealing to these problems due to their sufficient efficiency and accuracy. In this study, a novel framework for predicting the impact responses of foam-filled multi-layer lattice composite structures (FMLCSs) was proposed by combining the accurate finite element (FE) analyses, surrogate models, fast Fourier transform (FFT) method, and inverse FFT (IFFT) method. Firstly, reliable FM models were established to simulate the crashworthiness of the five FMLCSs under impact loading, including an analysis of energy transformation. Subsequently, surrogate models, namely radial basis function (RBF), polynomial response surface (PRS), Kriging (KRG), and back propagation neural network (BPNN), combined with methods of FFT and IFFT, were employed to predict the impact force-time series of the FMLCSs. More than 1000 frequency points were employed for each type of FMLCS, and all the R-square (R2) values of the established surrogate models exceeded 0.95, indicating that the proposed framework accurately predicted the impact duration and impact responses in the frequency domain. In addition, parameter sensitivity analysis revealed that a high peak impact force was accompanied by a short impact duration. Moreover, increasing the lattice-web height resulted in a significant increase in the impact duration.数值模拟可以为优化设计和运营管理提供有价值的见解；然而，它们通常是不切实际的，并且需要大量的计算。机器学习方法因其足够的效率和准确性而吸引着这些问题。本研究结合精确有限元（FE）分析、代理模型、快速傅立叶变换（FFT）方法和逆傅立叶变换（IFFT）方法，提出了一种预测泡沫填充多层晶格复合材料结构（FMLCSs）冲击响应的新框架。首先，建立了可靠的FM模型，模拟了5种fmlcs在冲击载荷下的耐撞性，并对能量转换进行了分析。随后，采用径向基函数（RBF）、多项式响应面（PRS）、Kriging （KRG）和反向传播神经网络（BPNN）等替代模型，结合FFT和IFFT方法对fmlcs的冲击力-时间序列进行预测。每种类型的FMLCS都使用了1000多个频率点，所有的R平方(R2)所建立的代理模型值均超过0.95，表明所提出的框架在频域上准确预测了冲击持续时间和冲击响应。此外，参数敏感性分析表明，峰值冲击力高，冲击持续时间短。此外，格腹板高度的增加导致冲击持续时间的显著增加。4D printed bio-inspired polygonal metamaterials with tunable mechanical propertiesXueli Zhou, Hongpei Liu, Jifeng Zhang, Lei Ren, Lu Zhang, Qingping Liu, Bingqian Li, Chao Xu, Luquan Rendoi:10.1016/j.tws.2024.112609具有可调机械性能的4D打印仿生多边形超材料Conventional vibration isolators are designed and assembled so that their structure and vibration isolation performance cannot be adjusted and have a single function when facing complex working conditions. Inspired by a cat's adaptive adjustment of its limb structure to land safely when leaping from a height, we designed a bio-inspired polygonal metamaterial and 3D-molded it based on 4D printing of shape memory polymers (SMP). Based on the shape memory effect of the SMP, the BPM can obtain arbitrary temporary shapes under the combined effect of temperature and force. According to the analysis of the energy absorption test, by change the compressive strain of the BPM temporary shape, it is possible to adjust the shape of the single-cell structure while decreasing its specific energy absorption by up to 80%. The locally controllable compressive deformation and programmable mechanical properties of the BPM structure are achieved through rational structural parameter design. In addition, thermally tunable vibration-absorbing behavior is achieved by combining the tunable stiffness properties of the printed material. This study provides new possibilities for intelligent tuning of cushion vibration isolators under complex and variable operating conditions.常规隔振器的结构和隔振性能在复杂工况下无法调整，功能单一。受猫在从高处跳跃时对肢体结构进行适应性调整以安全着陆的启发，我们设计了一种仿生多边形超材料，并基于形状记忆聚合物（SMP）的4D打印对其进行了3d成型。基于SMP的形状记忆效应，BPM可以在温度和力的共同作用下获得任意的临时形状。根据能量吸收试验分析，通过改变BPM临时形状的压缩应变，可以在调整单细胞结构形状的同时，将其比能量吸收降低高达80%。通过合理的结构参数设计，实现了BPM结构压缩变形局部可控和力学性能可编程。此外，通过结合印刷材料的可调刚度特性，实现了热可调的吸振性能。该研究为复杂多变工况下缓冲隔振器的智能调谐提供了新的可能性。A novel concurrent multiscale method based on the coupling of Direct FE2 and CPFEMYehui Cui, Zhilang Zhangdoi:10.1016/j.tws.2024.112610 一种基于直接FE2和CPFEM耦合的并行多尺度方法Performing concurrent simulations of macroscopic behaviors and microscopic structures using the crystal plasticity finite element method (CPFEM) presents a substantial difficulty with existing numerical techniques. To address this issue, a novel multi-scale method is proposed that couples CPFEM with a multiscale FEM, specifically Direct FE2. This facilitates the implementation of Direct CP-FE2 in this work. The micro representative volume elements (RVEs) equipped with a crystal plasticity constitutive model and the macro mesh are integrated into a monolithic solution scheme within the Direct FE2 framework. The proposed method integrates the multiscale simulation capability of Direct FE2 with the crystal plasticity model of CPFEM. Alpha titanium (α-Ti), which exhibits two distinct plastic mechanisms of slip and twinning, is chosen as the subject of investigation for conducting numerical experiments. The accuracy and efficiency of the Direct CP-FE2 model are evaluated through multiple plate tension and beam bending tests. The effective validation against the FEM model demonstrated the capability of Direct CP-FE2 to forecast macroscopic deformation behaviors. Meanwhile, the Direct CP-FE2 model can reveal the activation of slip/twinning systems and the evolution of crystal texture at a microscopic level. The influence of the grain orientation-dependent effect can be well considered into the macroscopic analysis with the help of Direct CP-FE2. Based on the testing examples, we demonstrate that the yield state of the macrostructure is enhanced when the crystal orientation is closer to the (0001) direction. Consequently, there exist very little crystal rotation behavior, hindering the evolution of the crystal texture.利用晶体塑性有限元方法（CPFEM）进行宏观行为和微观结构的并行模拟是现有数值技术的一大难点。为了解决这一问题，提出了一种新的多尺度方法，即耦合CPFEM和多尺度FEM，特别是直接有限元法。这有助于在本工作中实现Direct CP-FE2。在Direct FE2框架内，将具有晶体塑性本构模型的微代表体积元（RVEs）与宏观网格集成为整体求解方案。该方法将Direct FE2的多尺度模拟能力与CPFEM的晶体塑性模型相结合。选择具有滑移和孪晶两种不同塑性机制的α钛（α-Ti）作为研究对象进行数值实验。通过多次板拉伸和梁弯曲试验，对Direct CP-FE2模型的精度和效率进行了评价。通过对有限元模型的有效验证，证明了Direct CP-FE2预测宏观变形行为的能力。同时，Direct CP-FE2模型可以在微观水平上揭示滑移/孪晶系统的激活和晶体织构的演变。在Direct CP-FE2的帮助下，可以很好地考虑晶粒取向依赖效应的影响。实验结果表明，晶体取向越接近（0001）方向，宏观结构的屈服态越强。因此，晶体旋转行为很少，阻碍了晶体织构的演变。来源：复合材料力学仿真Composites FEM

【新文速递】2024年10月21日固体力学SCI期刊最新文章

International Journal of Solids and Structures

Journal of the Mechanics and Physics of Solids

Mechanics of Materials

International Journal of Plasticity

Thin-Walled Structures

【新文速递】2024年10月23日固体力学SCI期刊最新文章