【新文速递】2024年7月13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，Mechanics of Materials 2 篇，Thin-Walled Structures 2 篇

Journal of the Mechanics and Physics of Solids

Modelling and simulation of growth driven by mechanical and non-mechanical stimuli

Natalia M. Castoldi, Peter Pivonka, Luciano Teresi, Vittorio Sansalone

doi:10.1016/j.jmps.2024.105769

模拟和模拟由机械和非机械刺 激驱动的增长

Living tissues can remarkably adapt to their mechanical and biochemical environments through growth and remodelling mechanisms. Over the years, extensive research has been dedicated to understanding and modelling the complexities of growth. However, the majority of growth laws are based on phenomenological, ad hoc, proposed evolution equations. This work aims to describe a general bulk growth model that developed in the framework of generalised continuum mechanics. This new model of growth is based on a continuum description of the growth process and is an extension of the work of DiCarlo and Quiligotti of the early 2000s. This model builds on the virtual power principle, and the constitutive theory is thermodynamically consistent. The proposed framework allows the inclusion of different constitutive theories linking the elastic strain and stresses, together with accommodating different non-mechanical mechanisms. Moreover, the framework supports anisotropy of both the material and growth, allowing the exploration of complex growth processes further. The descriptive capabilities of the model are demonstrated through numerical benchmarks and simulations describing real-life scenarios, such as the growth of the spine and an artery. The simulation results indicate that the developed thermodynamic consistent growth model is versatile and holds the potential to capture the complexities of living tissue growth, offering valuable insights into biological phenomena and pathologies.

生物组织通过生长和重塑机制对其机械和生化环境具有显著的适应性。多年来，广泛的研究致力于理解和模拟增长的复杂性。然而，大多数生长规律是基于现象学的，特别的，提出的进化方程。这项工作旨在描述在广义连续介质力学框架内发展起来的一般体积增长模型。这种新的增长模型是基于对增长过程的连续描述，是DiCarlo和Quiligotti在21世纪初的工作的延伸。该模型建立在虚功率原理的基础上，本构理论在热力学上是一致的。提出的框架允许包含连接弹性应变和应力的不同本构理论，以及适应不同的非机械机制。此外，该框架支持材料和生长的各向异性，允许进一步探索复杂的生长过程。该模型的描述能力通过数值基准和模拟来证明，这些模拟描述了现实生活中的场景，例如脊柱和动脉的生长。模拟结果表明，所开发的热力学一致生长模型是通用的，具有捕获活组织生长复杂性的潜力，为生物现象和病理提供有价值的见解。

Mechanics of Materials

Multifunctional design of lattice metamaterial with desired thermal expansion behaviors using topology optimization

Zihao Yang, Yongcun Zhang, Zhangming Wu, Shutian Liu

doi:10.1016/j.mechmat.2024.105070

基于拓扑优化的具有理想热膨胀行为的晶格超材料多功能设计

Designing metamaterials with unprecedented coefficients of thermal expansion (CTEs) is an urgent demand for the majority engineering structures suffering from ambient temperature variation. Current studies on such artificial materials are mainly focused on achieving CTE tunnability through the purposeful design of material microstructure using an intuition based mechanism. In this study, the mechanical properties including maximum bulk modulus, specific stiffness and high thermal conductivity are combined with desired CTEs for designing multifunctional lattice metamaterials through the application of a non-intuitive topology optimization method. Toward this end, the continuous variable of member cross-sectional area is adopted to optimize lattice topology, section sizes of lattice members and material distributions, simultaneously. To meet the manufacturing requirements, an improved member intersection constraint that can cooperate with the present continuous design variable is introduced. A self-programmed routine that can be coupled with any commercial FEA software is developed to implement the present optimization method for the design of lattice metamaterials. Four typical optimization cases corresponding to different practical engineering issues are completed. Compared with the previously reported representative lattice metamaterials that are devised from the intuition or experience of designers, the optimization results obtained in this work demonstrate an obvious superiority in bulk modulus and specific stiffness. Additionally, a bimetallic specimen, fabricated using mechanical processing technology and composed of the metallic constituents Invar and Aluminum alloy, is presented to demonstrate the manufacturability of the optimized lattice microstructures.

设计具有前所未有的热膨胀系数(CTEs)的超材料是大多数受环境温度变化影响的工程结构的迫切需求。目前对这类人工材料的研究主要集中在利用基于直觉的机制，通过有目的地设计材料微观结构来实现CTE的可隧穿性。在本研究中，通过应用非直观的拓扑优化方法，将最大体积模量、比刚度和高导热系数等力学性能与所需的cte相结合，设计多功能晶格超材料。为此，采用构件截面面积连续变量，同时优化晶格拓扑结构、晶格构件截面尺寸和材料分布。为了满足制造要求，引入了一种改进的构件相交约束，该约束能与现有的连续设计变量相配合。开发了一个可与任何商业有限元软件耦合的自编程程序，以实现目前晶格超材料设计的优化方法。针对不同的实际工程问题，完成了四个典型的优化案例。与以往报道的根据设计者的直觉或经验设计的具有代表性的点阵超材料相比，本工作获得的优化结果在体积模量和比刚度方面具有明显的优势。此外，利用机械加工技术制备了由金属成分英瓦尔合金和铝合金组成的双金属试样，以证明优化后的点阵微结构的可制造性。

Warren truss inspired hierarchical beams for three dimensional hierarchical truss lattice materials

Fakhreddin Emami, Andrew J. Gross

doi:10.1016/j.mechmat.2024.105088

沃伦桁架启发分层梁三维分层桁架晶格材料

Networks of beams are a subject of increasing interest to create architected materials with exceptional mechanical properties and low density. This paper investigates the mechanical properties of one dimensional (1D) hierarchical beams for the development of three dimensional (3D) truss lattice materials. These 1D hierarchical beams are constructed in two configurations by placing axial and inclined struts in single and double laced Warren truss patterns in each side of a beam with polygon cross section. Analytical and numerical analyses have been used to characterize their mechanical properties, including the elastic modulus, second moment of area, and shear stiffness of hierarchical beams drawn from a broad design space. Also, the failure limits of the beams with respect to parent material failure and various buckling modes are probed. Finally, the hierarchical beams have been implemented as the constituent members of Kelvin and octet lattices, and the elastic modulus and failure boundaries of the second-order hierarchical lattices are evaluated. The investigation reveals the competition between the elastic properties in the individual hierarchical beams based on different combinations of the design variables. The stiffness of the designs under compression and bending is found to be a function of the axial member size and cross sectional shape of the hierarchical beam. On the other hand, the shear stiffness of hierarchical beam designs is a function of the inclined member size and their inclination angle. It is demonstrated that incorporating hierarchy in the Kelvin and octet truss lattices can enhance the load bearing capacity of designs at low relative densities when compared to their hollow counterparts. Also, it is shown that second-order hierarchical stretching and bending-dominated lattices incorporating first-order hierarchical beams, can not only achieve but also surpass the strength and stiffness scaling relations established for first-order lattices. This becomes particularly noteworthy when considering bending-dominated lattices, as the hierarchy can drive their stiffness towards the boundaries, enabling them to outperform their equivalent stretching-dominated rivals.

梁网是创造具有特殊机械性能和低密度的建筑材料的一个越来越受关注的主题。本文研究一维分层梁的力学性能，为开发三维桁架晶格材料提供参考。这些一维分层梁在两种配置中构造，通过在具有多边形截面的梁的每一侧放置轴向和斜向的单和双带沃伦桁架模式。分析和数值分析已被用于表征它们的力学性能，包括弹性模量、第二面积矩和剪切刚度，从广泛的设计空间绘制的分层梁。此外，还探讨了梁在母材破坏和各种屈曲模式下的破坏极限。最后，将分层梁实现为开尔文格和八元格的组成单元，并计算了二阶分层格的弹性模量和破坏边界。研究揭示了基于不同设计变量组合的单个分层梁的弹性性能之间的竞争。在压缩和弯曲下设计的刚度是轴向构件尺寸和分层梁截面形状的函数。另一方面，分层梁设计的抗剪刚度是倾斜构件尺寸及其倾角的函数。结果表明，与空心桁架相比，在开尔文桁架和八元桁架晶格中加入层次结构可以提高设计在低相对密度下的承载能力。研究还表明，包含一阶梁的二阶拉伸和弯曲控制格不仅可以达到甚至超过一阶格的强度和刚度标度关系。当考虑弯曲主导的格子时，这一点尤其值得注意，因为层次结构可以将它们的刚度推向边界，从而使它们的性能优于等效的拉伸主导的对手。

Thin-Walled Structures

Research on Innovative Fluid-Driven Pipe-Strut Tensegrity Structure

Shu Li, Akram Samy, Xingfei Yuan, Yongcan Dong, Zhendong Qiu

doi:10.1016/j.tws.2024.112221

新型流体驱动管杆张拉整体结构研究

As a self-equilibrated system under prestresses, the internal forces and geometric configurations of tensegrity structures are highly related. Consequently, by employing active control units internally, the lengths of structural components can be adjusted, enabling control over the structural shape and facilitating motion and actuation. Fluid actuation, as a common type of driving mechanism, is typically achieved by using external fluid actuators or directly replacing structural components with them. In order to better realize the combination of flexible, efficient and adaptable fluid-driven strategy with lightweight, flexible and adjustable tensegrity structure, this paper proposes an innovative pipe-strut tensegrity structure based on the topology of traditional tensegrity structure. In the proposed structure, conventional cables are replaced by flexible pipes to establish a continuous fluid path This construction concept promotes the flow of fluid within the structure, enabling the proposed structure to deform or move under the influence of the fluid. With structural and hydraulic analyses serving as the theoretical foundation, a simplified computational theory based on fluid-structure interaction is thoroughly investigated to analyze this innovative structure. Two specific examples are presented to demonstrate the feasibility of the novel configuration, validate the accuracy of the proposed calculation theory, and verify the possibility of movement and motion trend of the proposed fluid-driven pipe-strut structure.

张拉整体结构作为预应力作用下的自平衡体系，其内力与几何构型密切相关。因此，通过内部采用主动控制单元，可以调整结构部件的长度，从而实现对结构形状的控制，并促进运动和驱动。流体作动作为一种常见的驱动机构，通常采用外部流体作动器或直接用其替换结构部件来实现。为了更好地实现柔性、高效、适应性强的流体驱动策略与轻量化、柔性、可调张拉整体结构的结合，本文在传统张拉整体结构拓扑的基础上，提出了一种创新的管撑张拉整体结构。在所提出的结构中，用柔性管道代替传统的电缆，建立连续的流体路径。这种构造理念促进了结构内部流体的流动，使所提出的结构在流体的影响下变形或移动。以结构和水力分析为理论基础，深入研究了基于流固相互作用的简化计算理论来分析这种创新结构。通过两个具体算例验证了新结构的可行性，验证了所提计算理论的准确性，验证了所提流体驱动管支撑结构运动的可能性和运动趋势。

Random and harmonic responses of plain woven carbon fiber reinforced conical-conical shell based on machine learning multiscale modelling

Qingyang Huang, Lin Wang, Fenfei Hua, Qingquan You, Wenkai He, Honghao Zhou, Jie Gao, Wantong Wu, Xiaoqiang Zhou

doi:10.1016/j.tws.2024.112220

基于机器学习多尺度建模的素编织碳纤维增强锥形壳体随机谐响应

This study analyses the frequency-response characteristics under non-stationary base random acceleration and harmonic points force excitations of plain woven carbon fiber reinforced polymers (PW-CFRP) conical-conical shells comprehensively. Artificial neural network (ANN) based machine learning multiscale modelling strategy is introduced in the process of predicting the mechanical properties of PW-CFRP. The dataset is generated by randomization, linear fitting and two-step homogenization and then trained to generate an ANN to predict the mechanical properties of PW-CFRP. The governing equations of the conical-conical shell under random acceleration excitation are obtained according to the first order shear deformation theory (FSDT) and Hamilton's principle. After the structure is split along the circumference at the excitation points, the harmonic points force excitations are introduced based on the discontinuity condition between conical segments. Generalized differential quadrature (GDQ) is applied during the solving procedure. After comparison studies focusing on the frequency-response characteristics under two types of excitations, two examples on harmonic and random responses of conical-conical shell and conical-cylindrical shell are carried out separately. In this process, the effects of excitation type, excitation and response points, geometric parameters on the frequency-response characteristics are extensively analyzed, which proves efficiency and accuracy of the ANN based machine learning multiscale modelling strategy and the constructed GDQ based computational strategy.

本文全面分析了平纹编织碳纤维增强聚合物(PW-CFRP)锥形-锥形壳体在非平稳基底随机加速度和谐波点力激励下的频率响应特性。在预测PW-CFRP力学性能的过程中，引入了基于人工神经网络的机器学习多尺度建模策略。通过随机化、线性拟合和两步均匀化生成数据集，然后训练生成一个人工神经网络来预测PW-CFRP的力学性能。根据一阶剪切变形理论(FSDT)和哈密顿原理，得到了随机加速度激励下圆锥-圆锥壳的控制方程。结构在激励点沿圆周劈裂后，基于锥形段间的不连续条件引入谐波点力激励。在求解过程中应用了广义微分正交法(GDQ)。在对两种激励下的频率响应特性进行对比研究后，分别对圆锥-圆锥壳和圆锥-圆柱壳的谐波响应和随机响应进行了算例分析。在此过程中，广泛分析了激励类型、激励和响应点、几何参数对频率响应特性的影响，证明了基于人工神经网络的机器学习多尺度建模策略和构建的基于GDQ的计算策略的有效性和准确性。