【新文速递】2024年7月22日固体力学SCI期刊最新文章
今日更新：International Journal of Solids and Structures 2 篇，Thin-Walled Structures 3 篇
International Journal of Solids and Structures
Unlocking slip-mediated bending in multilayers: Efficient modeling and solutions with high precision and simplicity
Xiangtian Shen, Yueguang Wei, Yanwei Liu
doi:10.1016/j.ijsolstr.2024.112971
解锁滑动介导的多层弯曲:高精度和简单的高效建模和解决方案
This work introduces a novel approach to understanding the bending behavior of multilayer structures with weak interfaces. Despite the existence of various theoretical models, achieving high accuracy and computational efficiency remains a challenge. To address these limitations, we propose a Non-uniform Slip Model (NSM) governed by two essential dimensionless parameters: the number of layers and the shear factor. Utilizing the Semiparametric Hybrid Variational (SHV) method, we derive theoretical solutions that require less computational effort and offer enhanced accuracy. We further simplify the NSM through homogenization to the Uniform Slip Model (USM), yielding clear and concise analytical solutions for deflection curves and effective bending stiffness with high precision. The USM is also extended to account for nonlinear slipping interfaces with continuous shearing flow, providing an analytical stiffness expression that includes the bending angle. This extension explains the experimental observation of multilayered graphene’s bending stiffness, which decreases from cubic to linear with increasing number of layers due to continuous slip and dislocation between atomic layers. Our study delivers theoretical insights for analyzing slip-mediated bending in laminated materials, paving the way for the design and optimization of such structures
本文介绍了一种新的方法来理解具有弱界面的多层结构的弯曲行为。尽管存在各种各样的理论模型，但实现高精度和计算效率仍然是一个挑战。为了解决这些限制，我们提出了一个由两个基本无量纲参数控制的非均匀滑移模型(NSM):层数和剪切因子。利用半参数混合变分(SHV)方法，我们得到理论解决方案，需要更少的计算量，并提供更高的精度。我们进一步简化了NSM，将其均质化为均匀滑移模型(USM)，得到了清晰简洁的挠度曲线解析解和高精度的有效弯曲刚度。USM还扩展到考虑具有连续剪切流的非线性滑动界面，提供包含弯曲角的解析刚度表达式。这一扩展解释了多层石墨烯的弯曲刚度的实验观察，由于原子层之间的连续滑移和位错，随着层数的增加，石墨烯的弯曲刚度从立方减小到线性。我们的研究为分析滑移介导的层压材料弯曲提供了理论见解，为这种结构的设计和优化铺平了道路
Extension of Tsai-Hill failure concept for mixed-mode I/II fracture investigation of orthotropic materials considering T-stress effects
Ali Farahnak, Mahdi Fakoor
doi:10.1016/j.ijsolstr.2024.112991
考虑t应力效应的正交各向异性材料混合I/II型断裂研究中Tsai-Hill破坏概念的扩展
An essential study in the discourse surrounding composite materials is the investigation of their fracture mechanics due to the intricate nature of composite structures, it is necessary to take into account the presence of cracks and faults throughout the design process. In this research, within the context of linear elastic fracture mechanics, the fracture criterion for orthotropic materials under mixed mode II/I loading is presented by expanding the Tsai-Hill failure criterion. According to the crack, it may be aligned or perpendicular to the fibers; the criterion is stated for both cases. Also, the effects of the non-singular stress component on crack growth have been investigated. The mechanical and fracture data of Russian pine wood was extracted through tensile testing and the finite element (FE) method. The validity of the proposed criterion, in comparison with the experimental findings extracted in this research, has been proved. The precision of the previous proposed fracture criteria has been reviewed in comparison with the proposed criterion The appropriate behavior of the fracture limit curves compared to the experimental data shows the efficacy of the proposed criterion to predict the initiation and propagation of cracks in orthotropic materials.
由于复合材料结构的复杂性，研究其断裂力学是复合材料研究的一个重要内容，在设计过程中必须考虑到裂纹和断裂的存在。本研究在线弹性断裂力学的背景下，通过对Tsai-Hill破坏准则的扩展，提出了正交异性材料在II/I混合模式载荷下的断裂准则。根据裂纹的不同，它可以与纤维对齐或垂直;这两种情况都说明了标准。研究了非奇异应力分量对裂纹扩展的影响。通过拉伸试验和有限元法提取了俄罗斯松木的力学和断裂数据。通过与本研究中提取的实验结果的比较，证明了该准则的有效性。与实验数据相比，断裂极限曲线的适当行为表明了所提出的准则在预测正交异性材料裂纹的起裂和扩展方面的有效性。
Thin-Walled Structures
Seismic performance of hybrid-connection CFS shear walls with self-piercing rivet and self-tapping screw
Zhiqiang Xie, Ying Fan, Wenying Zhang, Xiyang Lei, Meini Su, Daxing Zhou, Xiangdong Zhang
doi:10.1016/j.tws.2024.112228
自穿铆钉与自攻螺钉混合连接CFS剪力墙的抗震性能
The previous test results indicate that the self-piercing riveted CFS shear wall exhibits the characteristics of high bearing capacity and stiffness, enhanced connection efficiency and mechanization degree. However, its deformation ability appears to be limited. Therefore, in order to improve the deformation capacity of the self-piercing riveted CFS shear wall and achieve the purpose of improving its seismic performance, this paper presents a novel hybrid-connection cold-formed steel (HCCFS) shear wall with self-piercing rivet (SPR) and self-tapping screw (STS). Five full-scale HCCFS shear wall specimens were tested under cycle loading to determine their failure mode, ductility, energy dissipation capacity, and stiffness degradation. A non-linear simplified analysis method of an HCCFS shear wall was proposed and the incremental dynamic analysis was conducted of a CFS structure with an HCCFS shear wall to further study the seismic performance. The results indicated that the primary failure modes of the HCCFS shear wall were steel sheet sheathing buckling, rivet head pull-over from sheet, and screw head pull-over from sheet. The hybrid connection type in which screws were added continuously significantly improved the seismic performance of shear walls. The proposed non-linear simplified analysis model accurately simulated the hysteric properties of shear walls. The seismic response modification coefficient (R = 6.5, Ω = 3.0) given in AISI S400 can be used to evaluate the seismic performance of a structure with an HCCFS shear wall.
前期试验结果表明，自穿铆接CFS剪力墙具有承载力和刚度高、连接效率高、机械化程度高等特点。然而，其变形能力似乎是有限的。因此，为了提高自穿铆接CFS剪力墙的变形能力，达到提高其抗震性能的目的，本文提出了一种新型自穿铆钉(SPR)和自攻螺钉(STS)混合连接冷弯型钢(HCCFS)剪力墙。在循环荷载作用下，对5个全尺寸HCCFS剪力墙试件进行了破坏模式、延性、耗能能力和刚度退化试验。提出了一种HCCFS剪力墙的非线性简化分析方法，并对带有HCCFS剪力墙的CFS结构进行了增量动力分析，进一步研究了其抗震性能。结果表明:HCCFS剪力墙的主要破坏模式为钢板护套屈曲、铆钉头脱板和螺钉头脱板;连续添加螺钉的混合连接方式显著提高了剪力墙的抗震性能。提出的非线性简化分析模型准确地模拟了剪力墙的滞回特性。AISI S400给出的地震反应修正系数(R = 6.5，Ω = 3.0)可用于评价HCCFS剪力墙结构的抗震性能。
Non-uniform elastic constraint modeling and stiffness identification for the bolted thin-walled cylindrical shell
Xin Liu, Yue Zhang, Jian Yang
doi:10.1016/j.tws.2024.112233
螺栓薄壁圆柱壳非均匀弹性约束建模及刚度辨识
To simulate the actual constraint condition, a novel non-uniform elastic constraint model with continuous stiffness variation and independent stiffness distribution is presented for dynamic modeling of the bolted thin-walled cylindrical shell. By combining the Marine Predators Algorithm, Genetic Algorithm, and modal shape recognition strategy, an accurate and efficient inverse identification method is developed to identify the constraint stiffness coefficients, based on the finite element models with bolt connections and non-uniform elastic constraint. Good agreement between the numerical and experimental results validates the correctness and effectiveness of the non-uniform elastic constraint model and its inverse identification method. The impacts of bolt number, stiffness coefficients and stiffness detuning on vibration characteristics of the shell with non-uniform elastic constraint are investigated. Results show that the parity of bolt number would change its impact pattern on natural frequencies, and the natural frequencies corresponding to lower circumferential wave numbers are more sensitive to the variation of stiffness coefficients. Increasing the bolt number can effectively reduce the sensitivity of vibration characteristics to the stiffness detuning of bolt connections, but large-scale stiffness detuning of bolt connections should be avoided especially when the number of bolts is large.
为了模拟实际约束条件，提出了一种具有连续刚度变化和独立刚度分布的非均匀弹性约束模型，用于螺栓连接薄壁圆柱壳的动力学建模。结合海洋掠食者算法、遗传算法和模态振型识别策略，基于螺栓连接和非均匀弹性约束的有限元模型，提出了一种准确、高效的约束刚度系数反识别方法。数值结果与实验结果吻合较好，验证了非均匀弹性约束模型及其反识别方法的正确性和有效性。研究了螺栓数、刚度系数和刚度失谐对非均匀弹性约束下壳体振动特性的影响。结果表明，螺栓数的宇称性会改变其对固有频率的影响规律，且较低周向波数所对应的固有频率对刚度系数的变化更为敏感。增加螺栓数量可以有效降低振动特性对螺栓连接刚度失谐的敏感性，但尤其在螺栓数量较大的情况下，应避免螺栓连接出现大规模的刚度失谐。
Analysis of Deformation and Multi-angle Tip Contact in a Combined Mechanism of Thin-walled Membrane Forces and Inextensible Layers in Soft Actuators
Mingyue Lu, Yanyan Wu, Zhao Zhang, Li Ding, Xing Ge, Xia Ye
doi:10.1016/j.tws.2024.112245
软执行器薄壁膜力与不可扩展层复合机构的变形与多角度尖端接触分析
Soft actuators have extensive applications in operations, are generally made of elastomers, and generate large deformation. It makes accurately predicting their deformation behavior challenging. This study considers the combined effects of chamber sidewall expansion and inextensible layer strain mechanisms on the actuator's bending and tip contact force. We separately model the expansion of the chamber sidewall and the strain in the inextensible layer using the expanding membrane and strain beam theory. The theoretical model presented to predict the contact area of the sidewall expanding membrane under multiple bending conditions. The analytical models for three actuator states are established: 1) Free space; 2) Tip contact at multiple angles; and 3) Grasping state. The proposed theoretical model accurately predicts deformation, force characteristics, and the requisite pressure for object grasping, and its applicability extends to similar soft actuators. Comparative analyses with finite element methods (FEM) and experimental results validate the model's computational efficiency, reduced design variables, and accurate prediction of diverse deformations and tip contact forces. Notably, the model outperforms with shorter computation times. The large and small chamber spacing errors are approximately 10% and 5%, respectively.
软执行器在作业中有广泛的应用，通常由弹性体制成，产生较大的变形。这使得准确预测它们的变形行为具有挑战性。本研究考虑了腔室侧壁膨胀和不可扩展层应变机制对执行器弯曲力和尖端接触力的综合影响。采用膨胀膜理论和应变梁理论分别对腔室侧壁的膨胀和不可扩展层的应变进行了建模。建立了预测多种弯曲条件下侧壁膨胀膜接触面积的理论模型。建立了三种作动器状态的解析模型:1)自由空间;2)尖端多角度接触;3)抓取状态。所提出的理论模型能准确地预测物体抓取时的变形、力特性和所需压力，其适用性扩展到类似的软执行器。与有限元方法(FEM)和实验结果的对比分析验证了该模型的计算效率，减少了设计变量，准确预测了各种变形和尖端接触力。值得注意的是，该模型具有更短的计算时间。大腔间距误差约为10%，小腔间距误差约为5%。
