【新文速递】2023年12月16日固体力学SCI期刊最新文章
今日更新：International Journal of Solids and Structures 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 2 篇
International Journal of Solids and Structures
A smooth Crack-Band Model for anisotropic materials: Continuum theory and computations with the RKPM meshfree method
Hoang Nguyen, Jiarui Wang, Yuri Bazilevs
doi:10.1016/j.ijsolstr.2023.112618
各向异性材料的光滑裂纹带模型:连续介质理论与RKPM无网格法计算
A smooth Crack Band Model (sCBM) is developed for anisotropic materials with both high and low magnitude of anisotropy. sCBM is primarily used as a regularization mechanism to enable capturing the correct size and shape of the fracture process zone (FPZ) as well as the smooth distribution of strain inside the zone. The versatility of the proposed sCBM formulation is demonstrated by its adaptability to any material law of choice. A Reproducing Kernel Particle Method (RKPM) is employed to discretize such formulation, the benefit of which is its ability to compute the Hessian of the displacement field (i.e., the sprain tensor), a key quantity in the sCBM theory, using only the nodal displacements as the problem unknowns. This makes the resulting formulation accurate and efficient, which is shown by the validations against size-effect and radial crushing experiments, illustrating the power of the proposed methodology for practical applications.
建立了高、低各向异性材料的光滑裂纹带模型(sCBM)。sCBM主要用作一种正则化机制，用于捕获断裂过程区(FPZ)的正确尺寸和形状以及区域内应变的平滑分布。所提出的sCBM配方的通用性证明了它对任何材料选择规律的适应性。采用再现核粒子法(RKPM)对这种公式进行离散化，其优点是能够计算位移场的Hessian(即扭伤张量)，这是sCBM理论中的一个关键量，仅使用节点位移作为问题未知数。这使得所得到的配方准确而高效，这是通过对尺寸效应和径向破碎实验的验证所显示的，说明了所提出的方法在实际应用中的力量。
International Journal of Plasticity
Fractional Order Viscoplastic Modeling of Anisotropically Overconsolidated Clays with Modified Isotach Viscosity
Wei Cheng, Zhen-Yu Yin
doi:10.1016/j.ijplas.2023.103858
修正等黏度的各向异性超固结粘土分数阶粘塑性模型
Current overstress typed elastic viscoplastic models fall short in describing some time-dependent mechanical behaviors of anisotropically overconsolidated clays comprehensively. This paper presents a rigorous fractional order anisotropic elastic viscoplastic two-surface model for such clays, based on the principles of fractional consistency viscoplasticity and bounding or subloading surface theory. First, a three-dimensional formulation of isotach viscosity is proposed and integrated into two rate-dependent surfaces, i.e., the loading surface and yield surface. Then, by incorporating the stress-fractional operator of the rate-dependent loading surface into isotropic, progressive, and rotational hardening rules, the incremental form of stress-strain-time model with a fractional order viscoplastic flow rule is developed by meeting the consistency condition on the loading surface. Accordingly, the proposed model can not only maintain the predictive capabilities of a classic bounding surface model but also describe the general features of the time-dependent behavior under various stress conditions. Validation and versatility of the proposed fractional order elastic viscoplastic model are successfully evaluated against constant strain-rate and stress relaxation tests on anisotropically overconsolidated resedimented Boston Blue clay.
目前的超应力型弹粘塑性模型在全面描述各向异性超固结粘土的一些随时间变化的力学行为方面存在不足。本文基于分数阶粘塑性原理和边界面或次加载面理论，建立了分数阶各向异性弹性粘塑性两面模型。首先，提出了等黏度的三维公式，并将其整合为两个速率相关的曲面，即加载面和屈服面。然后，通过将速率相关加载面的应力分数算子纳入各向同性、渐进和旋转硬化规则，在满足加载面上一致性条件的情况下，建立了具有分数阶粘塑性流动规则的应力-应变-时间增量模型。因此，所提出的模型既能保持经典边界面模型的预测能力，又能描述各种应力条件下随时间变化行为的一般特征。通过对各向异性超固结再沉积波士顿蓝粘土的恒应变速率和应力松弛试验，成功地评估了所提出的分数阶弹粘塑性模型的有效性和通用性。
Thin-Walled Structures
Effect of density value and gradient distribution on the deformation mechanism of foamed concrete
Liangliang Xu, Xi Li, Muhammad Atif, Yulong Li
doi:10.1016/j.tws.2023.111487
密度值和梯度分布对泡沫混凝土变形机理的影响
Foamed concrete is an essential material in engineering that can be categorized into two types based on density distribution, namely uniform foamed concrete (UFC) and gradient foamed concrete (GFC). However, there exists a research gap concerning the mesoscopic deformation mechanism of UFC and GFC. The objective of this research is to bridge this gap by examining the quasi-static compression characteristics of UFCs with three distinct densities and GFCs with different density sequences. The results reveal that the strength of pore walls significantly influences the failure mechanism of UFCs with varying densities. Specifically, UFCs with low density exhibit weak pore-wall strength, leading to stress concentration at the pore-wall junction. During compression, these weak pore walls are widely dispersed within the specimen, resulting in a powdering failure mode. Conversely, UFCs with high density possess stronger pore walls, which prevent the powdering failure mode by maintaining adequate pore-wall strength. Nevertheless, the existence of a dominant crack within the specimen results in a splitting failure mode. In the context of GFCs, deformation occurs in a sequence from low to high density, with each layer exhibiting a failure mode corresponding to its density. Note that the last-deforming layer in this brittle gradient foam cannot attain the strength of the corresponding uniform foam. This is due to the failure of the second layer, which results in uneven contact surfaces and prompts the third layer to crack simultaneously. Finally, a statistical model is developed to forecast the compressive stress-strain curve of foamed concrete, demonstrating remarkable agreement with experimental data.
泡沫混凝土是工程中必不可少的材料，根据其密度分布可分为均匀泡沫混凝土(UFC)和梯度泡沫混凝土(GFC)两种。然而，对于UFC和GFC的细观变形机理的研究还存在空白。本研究的目的是通过研究具有三种不同密度和不同密度序列的GFCs的准静态压缩特性来弥补这一差距。结果表明，孔壁强度对不同密度ufc的破坏机制有显著影响。具体而言，低密度ufc的孔壁强度较弱，导致孔壁交界处应力集中。在压缩过程中，这些脆弱的孔壁广泛分散在试样内部，导致粉末状破坏模式。相反，高密度的ufc具有更强的孔壁，通过保持足够的孔壁强度来防止粉化破坏模式。然而，在试样中存在一个主导裂纹导致分裂破坏模式。在GFCs的情况下，变形发生在从低到高密度的序列中，每一层都表现出与其密度相对应的破坏模式。注意，这种脆性梯度泡沫中的最后变形层不能达到相应的均匀泡沫的强度。这是由于第二层的失效，导致接触面不均匀，并促使第三层同时开裂。最后，建立了预测泡沫混凝土压应力-应变曲线的统计模型，该模型与试验数据吻合较好。
Dynamic analysis of a plate system coupled through several nonlinear spring-mass couplers
Yuhao Zhao, Deshui Xu
doi:10.1016/j.tws.2023.111490
若干非线性弹簧-质量耦合器耦合的平板系统动力学分析
Nowadays, plates have been widely used in various engineering fields, where nonlinear additional equipment is designed to control the vibration of plates. However, the current studies mainly concentrate on the single-plate system with nonlinear additional equipment. Seldom studies use nonlinear couplers to connect the plate system, making the working mechanism of nonlinear couplers on the vibration responses of the plate system unclear, limiting the application of nonlinear couplers on vibration control of the plate system. To explore the potential application of nonlinear couplers, this work introduces nonlinear spring-mass couplers to connect the plate system, where the transverse vibration analysis model of the plate system coupled through nonlinear couplers is established. The Galerkin truncation method (GTM) is used to predict vibration responses of the plate system coupled through nonlinear couplers. After ensuring the validation of numerical results, forced vibration responses of the plate system coupled by nonlinear couplers are investigated. According to numerical results, responses in the vibration of the plate system are influenced by nonlinear couplers greatly. Choosing suitable parameters for nonlinear couplers plays an important role in the vibration control of the plate system. Under a certain parameter range of nonlinear couplers, responses in vibration present complex characters. Under complex responses, the target energy transfer is present in the vibration responses of the plate system.
如今，板在各种工程领域中得到了广泛的应用，在这些领域中设计了非线性附加装置来控制板的振动。然而，目前的研究主要集中在带有非线性附加设备的单 平板系统上。很少有研究使用非线性耦合器连接板系，使得非线性耦合器对板系振动响应的工作机理不清楚，限制了非线性耦合器在板系振动控制上的应用。为探索非线性耦合器的潜在应用，本文引入非线性弹簧-质量耦合器连接平板系统，建立了通过非线性耦合器耦合的平板系统横向振动分析模型。采用伽辽金截断法(GTM)对非线性耦合器耦合的平板系统进行了振动响应预测。在保证数值结果的正确性的基础上，对非线性耦合器耦合下的板系强迫振动响应进行了研究。数值结果表明，非线性耦合器对平板系统的振动响应影响很大。选择合适的非线性耦合器参数对平板系统的振动控制具有重要意义。在非线性耦合器的一定参数范围内，其振动响应呈现出复杂的特征。在复响应下，靶能量传递存在于板系振动响应中。
