今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 3 篇
Exact thermal fracture analysis of multiferroic composites weakened by a crack containing medium
Zhou Y.T., Zheng T., Luo Q.H., Li F.J.
doi:10.1016/j.ijsolstr.2023.112518
受含裂纹介质削弱的多铁素体复合材料的精确热断裂分析
The purpose of the present work is to study the thermal fracture behaviors of multiferroic composites weakened by a propagating tangential crack containing a medium. The thermally, magnetically and (or) electrically impermeable/permeable crack models in the static state are the special cases of the present dynamic, partially permeable one. The heat conduction equation and magneto-electro-elastic governing equations with boundary conditions are converted analytically into singular integral equations which are solved exactly to yield the full plane solutions. Three cases of the eigenvalue properties are considered depending on material properties. Based on those solutions, various loadings generated by the crack interior are determined. Numerical experiments are conducted, which show that the thermal fracture behaviors depend on the magnetic, electric and elastic properties of the crack interior as well as the external loadings and inherent material properties characterized by the crack moving velocity.
本研究的目的是研究含有介质的切向裂纹传播所削弱的多铁素体复合材料的热断裂行为。静态的热、磁和(或)电不渗透/渗透裂缝模型是目前动态的部分渗透裂缝模型的特例。带有边界条件的热传导方程和磁电弹性调控方程通过解析转换为奇异积分方程,并通过精确求解得到全平面解。根据材料特性,考虑了三种特征值特性情况。根据这些解,确定了裂缝内部产生的各种载荷。数值实验表明,热断裂行为取决于裂纹内部的磁、电和弹性特性,以及外部载荷和以裂纹移动速度为特征的固有材料特性。
Data-driven hyperelasticity – Part II: A canonical framework for anisotropic soft biological tissues
Tikenoğulları Oğuz Ziya, Açan Alp Kağan, Kuhl Ellen, Dal Hüsnü
doi:10.1016/j.jmps.2023.105453
数据驱动的超弹性--第二部分:各向异性软生物组织的典型框架
In this work, we present a novel anisotropic data-driven hyperelasticity framework for the constitutive modeling of soft biological tissues that allows direct incorporation of experimental data into the constitutive model, without requirement of a predetermined mathematical formula for the strain–energy density function. The data-driven framework is constructed through a dispersion-type anisotropic formulation based on a generalized structure tensor in the sense of Holzapfel et al. (J. R. Soc. Interface 12:20150188, 2015) that take into account in- and out of plane dispersion. The partial derivatives of the strain energy density functions are replaced with appropriate B-spline interpolations where the control points are calibrated against experimental data obtained from uniaxial tension, triaxial shear, and (equi)biaxial tension deformations. The model calibration phase incorporates the normalization condition and the polyconvexity condition is enforced through the control points of the B-splines in order to ensure a stable constitutive response that allows unique solution in finite element analysis. The predictive capabilities of the proposed model are shown against linea alba, rectus sheath, aneurysmal abdominal aorta, and myocardium tissues. On the numerical side, the stress and moduli expressions of the model are derived and implemented into the finite element method. The performance of the model is demonstrated through representative boundary value problems.
在这项工作中,我们提出了一种新颖的各向异性数据驱动超弹性框架,用于软生物组织的构成建模,可将实验数据直接纳入构成模型,而无需预先确定应变能量密度函数的数学公式。数据驱动框架是通过基于 Holzapfel 等人(J. R. Soc. Interface 12:20150188, 2015)意义上的广义结构张量的弥散型各向异性公式构建的,该公式考虑了平面内和平面外的弥散。应变能密度函数的偏导数由适当的 B-样条插值代替,控制点根据从单轴拉伸、三轴剪切和(等)双轴拉伸变形中获得的实验数据进行校准。模型校准阶段包含归一化条件,并通过 B-样条曲线的控制点强制执行多凸性条件,以确保稳定的构成响应,从而在有限元分析中实现唯一求解。所提出模型的预测能力针对白线、直肌鞘、动脉瘤性腹主动脉和心肌组织进行了展示。在数值方面,推导出了模型的应力和模量表达式,并将其应用到有限元方法中。通过具有代表性的边界值问题证明了模型的性能。
Effect of anisotropic stiffness degradation on the forced vibration of cylindrical shells
Li Linfeng, Cheng Li, Liu Weining, Yu Xiang
doi:10.1016/j.tws.2023.111255
各向异性刚度退化对圆柱形壳体受迫振动的影响
Structural defects are commonly encountered in engineering applications. They can significantly affect not only the structural integrity but also the natural frequencies and vibration responses of cylindrical shells subject to external loading. This study proposes a novel concept of stiffness degradation to analyze the effect of defects on the vibration of shell structures. Specifically, stiffness degradation factors (SDFs) are introduced into the model of a cylindrical shell based on Sanders shell theory, and their influences on the dynamic response of an infinite-length cylindrical shell are evaluated by analyzing vibrations at multiple locations. The results show that vertical vibrations at receiver points located away from the driving point are more susceptible to the stiffness degradation, particularly at higher frequencies. The degradation of flexural stiffness has a greater effect on the vibration of cylindrical shells than the degradation of membrane stiffness, particularly in terms of the resonant frequency decrease. Furthermore, stiffness degradation in the circumferential direction has a greater effect on shell vibration than in the longitudinal direction. By examining the effects of eight SDFs separately, it is revealed that the vibration response of a cylindrical shell is affected by the directions and types of stiffness degradation, the frequency range, and the observation point. Overall, this study provides a general analytical framework for analyzing the vibration response of cylindrical shells including the effect of anisotropic stiffness degradation, which could be applied to composite shell structures with directional fiber orientations and shell structures with various defect modes.
结构缺陷是工程应用中经常遇到的问题。它们不仅会严重影响结构的完整性,还会影响圆柱形壳体在外部载荷作用下的固有频率和振动响应。本研究提出了一种新的刚度退化概念,用于分析缺陷对壳结构振动的影响。具体来说,基于桑德斯壳理论,在圆柱壳模型中引入刚度退化因子(SDF),并通过分析多个位置的振动来评估其对无限长圆柱壳动态响应的影响。结果表明,远离驱动点的接收点的垂直振动更容易受到刚度退化的影响,尤其是在较高频率下。与膜刚度退化相比,挠曲刚度退化对圆柱形壳体振动的影响更大,尤其是在共振频率降低方面。此外,圆周方向的刚度退化比纵向方向的刚度退化对壳体振动的影响更大。通过分别研究八种 SDF 的影响,发现圆柱形壳体的振动响应受刚度退化的方向和类型、频率范围和观测点的影响。总之,本研究为分析圆柱形壳体的振动响应(包括各向异性刚度退化的影响)提供了一个通用的分析框架,可应用于具有定向纤维取向的复合材料壳体结构和具有各种缺陷模式的壳体结构。
Response of aluminium honeycomb sandwich panels under combined shock and impact loading: Experimental and numerical investigations
Li Lang, Jia Fusen, Liu Lu, Yu Runpei, Zhang Qiancheng, Li Lei
doi:10.1016/j.tws.2023.111256
铝蜂窝夹芯板在冲击和撞击联合载荷下的响应:实验和数值研究
The performance of sandwich structures against individual shock loading and fragment impact loading has been extensively examined, but little is known about their performance in the presence of simultaneous shock and impact loading. Based on a recently developed composite projectile to simulate combined shock and single fragment impact loading, the performance of aluminum honeycomb core sandwich panels (HCSPs) against combined loading is methodically examined. The achieved results reveal that the combined loading exhibits a synergistic effect compared to the single loading, i.e., increased damage of the sandwich panel and enhanced perforation resistance of the sandwich panel. After that, a three-dimensional finite element simulation is performed to explore the underlying mechanism of the synergistic effect. Numerical analysis indicates that the increased damage is a result of perforation-induced reduction of load-carrying capacity of sandwich panel, while the enhanced perforation resistance is the result of deflecting-induced perforation time delay of the perforation process. Finally, the parametric investigation of sandwich geometries such as asymmetric face sheets, core density, and core height is comprehensively conducted. The gained results reveal that both performance and synergistic effect due to combined loading are sensitive to these parameters.
夹层结构在承受单个冲击荷载和碎片冲击荷载时的性能已得到广泛研究,但对其在同时承受冲击荷载和碎片冲击荷载时的性能却知之甚少。基于最近开发的复合弹丸来模拟组合冲击和单个碎片冲击载荷,对铝蜂窝芯夹层板(HCSP)在组合载荷下的性能进行了系统研究。研究结果表明,与单一载荷相比,组合载荷具有协同效应,即增加了夹芯板的损坏程度,同时增强了夹芯板的抗穿孔能力。随后,进行了三维有限元模拟,以探索协同效应的内在机理。数值分析表明,损坏加剧是穿孔导致夹芯板承载能力下降的结果,而穿孔阻力增强则是穿孔过程中挠曲导致穿孔时间延迟的结果。最后,对非对称面片、芯材密度和芯材高度等夹层几何形状进行了全面的参数化研究。研究结果表明,组合加载的性能和协同效应对这些参数都很敏感。
Blast performance of 3D-printed auxetic honeycomb sandwich beams
Yan Zichen, Liu Yan, Yan Junbo, Wu Wen, Bai Fan, Huang Fenglei
doi:10.1016/j.tws.2023.111257
三维打印辅助蜂窝夹层梁的抗爆性能
Little research has been conducted on comparing the blasting characteristics between the regular hexagonal and auxetic honeycomb sandwich beams (RHSBs and AHSBs). To address this gap in knowledge, the study utilised both experimental and numerical analyses. The HSBs consisted of steel top and rear face sheets bonded to a stainless- steel honeycomb core. The parameters considered in this test included the core configuration (regular vs. auxetic hexagonal) and face-core bonding method (adhesive vs. integrated). Results revealed that at scaled distances of 0.8617 m/kg1/3 and 0.7971 m/kg1/3, the AHSB core exhibited a reduction in mid-span displacement of only 3.3% and 3.7%, respectively, compared to the RHSB core. However, the compression value of the AHSB core significantly exceeded that of the RHSB core by 171.5% and 161.5%, respectively. This finding indicates that auxetic honeycomb cores possess enhanced energy absorption capacity to withstand blast loading. In addition, using unbonded face sheets increases the range of local cell deformation and decreases the global flexural bending by 22.66% and 24.14% at scaled distances of 0.8617 m/kg1/3 and 0.7971 m/kg1/3, respectively, compared to the AHSBs with face sheet debonding. To further investigate the damage mechanism of HSBs subjected to blast loading, a well-validated finite element model was employed. Notably, parametric simulations demonstrated that the dynamic behaviour of AHSBs under blast loading is significantly influenced by cell wall thickness, face sheet thickness, and cell angle.
在比较常规六边形和辅助蜂窝夹层梁(RHSBs 和 AHSBs)的爆破特性方面,研究很少。为了填补这一知识空白,本研究采用了实验和数值分析方法。蜂窝夹层梁由顶部和后部钢板组成,钢板与不锈钢蜂窝芯粘合在一起。试验中考虑的参数包括蜂窝芯结构(规则六边形与辅助六边形)和面芯粘接方法(粘接与集成)。结果显示,与 RHSB 核心相比,在 0.8617 m/kg1/3 和 0.7971 m/kg1/3 的比例距离下,AHSB 核心的中跨位移分别只减少了 3.3% 和 3.7%。然而,AHSB 芯材的压缩值分别比 RHSB 芯材高出 171.5% 和 161.5%。这一发现表明,辅助蜂窝芯具有更强的能量吸收能力,可以承受爆炸荷载。此外,在 0.8617 m/kg1/3 和 0.7971 m/kg1/3 的缩放距离下,使用未粘结面片与使用面片脱粘的 AHSB 相比,局部单元变形范围增大,整体弯曲度降低了 22.66% 和 24.14%。为了进一步研究承受爆炸荷载的高密度聚苯乙烯的破坏机理,我们采用了经过验证的有限元模型。值得注意的是,参数模拟结果表明,在爆炸荷载作用下,AHSB 的动态行为受到电池壁厚度、面片厚度和电池角度的显著影响。