Computers & Structures最新文献_第2页

Offline iteration-based real-time hybrid simulation for high-fidelity fluid-structure dynamic interaction in structures subjected to seismic excitation 基于离线迭代的实时混合模拟，用于受地震激励结构中的高保真流固动力相互作用

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-11-04 DOI: 10.1016/j.compstruc.2024.107579

Yuchen Hu , Yafei Zhang , Zihao Zhou , Ning Li , Dan Zhang

This study introduces an offline iteration-based real-time hybrid simulation (OI-RTHS) method, a novel approach for simulating fluid–structure dynamic interaction (FSDI) under seismic excitation. With this method, hydrodynamic forces are treated as a physical substructure, while numerical computation and servo loading are performed independently throughout the entire duration of the seismic event. By iteratively correcting the input command signals and obtaining the output response signals during each iteration process, they can eventually achieve balanced coordination at the boundaries. This characteristic introduces real hydrodynamic data to address the limitations of purely numerical theoretical analysis, ensuring high fidelity. Additionally, it reduces the need for real-time communication between numerical computation and servo loading, thereby reducing hardware and software requirements. In this study, experimental verification of the proposed method is conducted, and the results illustrate that the method can address the convergence issue of dynamic response for FSDI of structures in the water after a finite number of iterations. Moreover, regarding the hydrodynamic force as a physical substructure helps prevent errors arising from repeated loading processes, enabling the benefits of the OI-RTHS method. This study offers potential insights for the research on the FSDI of structures, also other environmental loadings.

本研究介绍了一种基于离线迭代的实时混合模拟（OI-RTHS）方法，这是一种模拟地震激励下流体-结构动力相互作用（FSDI）的新方法。采用这种方法，流体动力被视为物理子结构，而数值计算和伺服加载则在地震事件的整个持续时间内独立进行。通过迭代修正输入指令信号，并在每次迭代过程中获得输出响应信号，最终实现边界的平衡协调。这一特点引入了真实的流体力学数据，解决了纯数值理论分析的局限性，确保了高保真度。此外，它还减少了数值计算与伺服加载之间的实时通信需求，从而降低了硬件和软件要求。本研究对所提出的方法进行了实验验证，结果表明该方法可以在有限次迭代后解决水中结构 FSDI 动态响应的收敛问题。此外，将水动力视为物理子结构有助于防止重复加载过程产生的误差，从而实现 OI-RTHS 方法的优势。这项研究为结构的 FSDI 以及其他环境荷载的研究提供了潜在的启示。

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引用次数: 0

Digital twins-boosted identification of bridge vehicle loads integrating video and physics 整合视频和物理的数字双胞胎增强型桥梁车辆荷载识别技术

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-11-04 DOI: 10.1016/j.compstruc.2024.107578

Junyi Tang , Junlin Heng , Lin Feng , Zhongru Yu , Zhixiang Zhou , Charalampos Baniotopoulos

Traffic loads are very critical in bridge digital twins for assessing the deterioration state and structural integrity of road bridges. The existing load rating methods are complicated and time-consuming, necessitating more efficient and intelligent approaches to identify and evaluate safe load capacities. This paper presents a digital twins-boosted approach to identify vehicle loads on road bridges by integrating video records and related physic information. The convolutional neural network (CNN) is adapted with a proposed pixel scale factor (PSF) method to track the motion and dimension of vehicles crossing the bridge. Based on the tracked vehicle data, the time-dependent traffic flow is regenerated via traffic simulation models. Due to the correlation in vehicle loads within a road network, the detailed weight of each vehicle in the traffic flow is inferred using related vehicle load models, e.g., the model established from nearby tollgate data in the case study. After a preliminary verification in the laboratory, a field trial test is carried out to validate the proposed approach in identifying the traffic flow. Then, finite element (FE) simulations are integrated into the approach to predict the vehicle-inducted structural response of an urban arch bridge. The prediction shows a satisfying agreement with the measurement by sensors, which validates the proposed approach in identifying traffic loads. Moreover, compared with purely data-driven methods, the proposed approach demands less training effort and provides more details due to the integration of physics. In general, the output not only offers a promising solution for the digital twins of traffic loads at low costs, but also highlights the integration of visual data and physics in solving engineering issues.

在桥梁数字双胞胎中，交通荷载对于评估道路桥梁的老化状态和结构完整性至关重要。现有的荷载分级方法复杂且耗时，因此需要更高效、更智能的方法来识别和评估安全荷载能力。本文提出了一种数字孪生增强方法，通过整合视频记录和相关物理信息来识别道路桥梁上的车辆荷载。卷积神经网络（CNN）与提议的像素比例因子（PSF）方法相匹配，可跟踪过桥车辆的运动和尺寸。根据跟踪的车辆数据，通过交通仿真模型重新生成随时间变化的交通流。由于道路网络中车辆负载的相关性，交通流中每辆车的详细重量是通过相关车辆负载模型推断出来的，例如案例研究中通过附近收费站数据建立的模型。在实验室进行初步验证后，我们进行了实地试验，以验证所提出的交通流识别方法。然后，将有限元（FE）模拟纳入该方法，以预测城市拱桥的车辆感应结构响应。预测结果与传感器的测量结果显示出令人满意的一致性，从而验证了所提出的交通荷载识别方法。此外，与纯粹的数据驱动方法相比，所提出的方法对训练的要求更低，而且由于融入了物理学原理，还能提供更多细节。总之，该成果不仅为低成本的交通负荷数字双胞胎提供了一个有前途的解决方案，而且还突出了在解决工程问题时视觉数据与物理学的结合。

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引用次数: 0

A novel modular origami strategy: Achieving adjustable Poisson’s ratio and tunable distinctive mechanical properties for versatile applications 新颖的模块化折纸策略：实现可调节的泊松比和可调整的独特机械特性，满足多种应用需求

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-11-02 DOI: 10.1016/j.compstruc.2024.107566

Yongtao Bai , Chen Chen , Yao Chen , Ruining Zhu

The exigencies of intricate environments necessitate the conception of structures exhibiting extraordinary performance. In response, we devised a foldable modular origami structure by combining Miura-Origami and perforated plates, employing a novel design strategy. We substantiated that this structure manifests adjustable Poisson’s ratios in diverse directions, spanning from negative values to positive, and can even approach infinity. While singular modular origami structures demonstrate inferior performance compared to periodic configurations, our focus has shifted to a more comprehensive analysis. Therefore, we conducted finite element analyses to scrutinize the mechanical behavior of periodically arranged modular origami structures. Remarkably, the same structure can exhibit either analogous or entirely disparate mechanical properties in distinct folding states. The inherent variability in Poisson’s ratio and mechanical performance opens new possibilities for applications in prospective complex environments, such as unfolding thin-walled structures, structural load-bearing, energy absorption, and so forth.

复杂的环境要求我们设计出具有非凡性能的结构。为此，我们采用新颖的设计策略，将三浦折纸和穿孔板相结合，设计出一种可折叠的模块化折纸结构。我们证实，这种结构在不同方向上表现出可调泊松比，从负值到正值，甚至可以接近无穷大。与周期性结构相比，单一模块化折纸结构的性能较差，因此我们将重点转向了更全面的分析。因此，我们进行了有限元分析，以仔细研究周期性排列的模块化折纸结构的机械行为。值得注意的是，在不同的折叠状态下，同一结构既可以表现出类似的机械性能，也可以表现出完全不同的机械性能。泊松比和机械性能的内在可变性为未来复杂环境中的应用提供了新的可能性，例如薄壁结构的展开、结构承重、能量吸收等。

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引用次数: 0

Stress-constrained topology optimization using the velocity field level set method 利用速度场水平集法进行应力约束拓扑优化

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-11-02 DOI: 10.1016/j.compstruc.2024.107577

Wei Cheng , Xiaopeng Zhang , Tiannan Hu , Jing Li , Yaguang Wang

This paper proposes a stress-constrained structural topology optimization method in the velocity field level set framework. To avoid the strength failure in structures, the stress should meet certain strength criteria at all material points. This point-wise constraint brings great difficulty to topology optimization. Instead of using the traditional aggregation scheme, we propose a new stress constraint in the single domain integral form, which is mathematically equivalent to the point-wise stress limitation and enables the precise stress control throughout the entire material domain without introducing numerous constraints. Its simple expression with relatively low non-linearity facilitates the optimization formulation, the sensitivity analysis and the numerical implementation. Here, the velocity field level set method is used for the stress-constraint topology optimization. The implicit material representation by the level set model is combined with the body-fitted mesh, which provides a clear and smooth material boundary with high numerical calculation accuracy for the stress and the sensitivity. Moreover, the velocity field level set method maps the original boundary variation-based optimization problem from the functional design space into a finite-dimensional one by introducing the velocity field design variables. Thus, it allows using of the general mathematical optimization algorithms in the level set model, which provides an efficient and steady way to deal with the stress-constrained optimization problems.

本文在速度场水平集框架下提出了一种应力约束结构拓扑优化方法。为避免结构强度失效，所有材料点的应力都应满足一定的强度标准。这种以点为单位的约束给拓扑优化带来了很大困难。我们没有采用传统的聚合方案，而是提出了一种新的单域积分形式的应力约束，它在数学上等同于点向应力限制，可以在不引入大量约束的情况下对整个材料域进行精确的应力控制。它的表达式简单，非线性相对较低，有利于优化表述、灵敏度分析和数值实现。这里采用速度场水平集方法进行应力约束拓扑优化。水平集模型的隐式材料表示与体拟合网格相结合，提供了清晰平滑的材料边界，并具有较高的应力和灵敏度数值计算精度。此外，速度场水平集方法通过引入速度场设计变量，将原来基于边界变化的优化问题从函数设计空间映射到有限维空间。因此，它允许在水平集模型中使用一般的数学优化算法，为处理应力受限的优化问题提供了一种高效、稳定的方法。

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引用次数: 0

Optimal thickness distribution design for blending hybrid composite laminates using Buckling Factor and Failure Index prediction 利用屈曲因子和失效指数预测进行混合混合复合材料层压板的最佳厚度分布设计

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-31 DOI: 10.1016/j.compstruc.2024.107562

Thanh N. Huynh, Jaehong Lee

This article introduces an extension to the Optimal Thickness Prediction (OTP) approach for solving the hybrid material composite laminate blending optimization problem considering both Buckling Factor and Failure Index constraints. The proposed optimization approach solves the blending optimization problem with a two-stage procedure. The Stacking Sequence of the laminate is first optimized using optimization algorithms, and then utilized as the input for the CNN-based prediction model to predict the corresponding optimal regional thickness. The present extended approach expands the dimension capacity of the OTP model by including an additional laminate material input dimension and Failure Index output dimension. The additional features broaden the scope of the OTP model to simultaneously handle more design variables and constraints. An integration of the proposed approach with a lamination guideline-based Genetic Algorithm is presented. A hybrid material variation of the 18-panel horseshoe blending optimization problem is introduced and utilized for demonstration of the effectiveness of the proposed approach. The obtained result highlights the significant improvement in performance of the integrated method over the base algorithm.

本文介绍了最优厚度预测（OTP）方法的扩展，用于解决同时考虑屈曲因子和失效指数约束的混合材料复合层压板混合优化问题。所提出的优化方法采用两阶段程序解决混合优化问题。首先使用优化算法优化层压板的堆叠顺序，然后将其作为基于 CNN 的预测模型的输入，以预测相应的最佳区域厚度。本扩展方法通过增加层压板材料输入维度和失效指数输出维度，扩大了 OTP 模型的维度容量。新增功能扩大了 OTP 模型的范围，可同时处理更多的设计变量和约束条件。本文介绍了将所提出的方法与基于层压准则的遗传算法进行整合的情况。介绍了 18 面板马蹄形混合优化问题的混合材料变体，并利用该变体演示了所提方法的有效性。结果表明，与基础算法相比，集成方法的性能有了显著提高。

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引用次数: 0

An asymmetric pinching damaged hysteresis model for glubam members: Parameter identification and model comparison 胶合构件的非对称捏合损坏滞后模型：参数识别和模型比较

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-31 DOI: 10.1016/j.compstruc.2024.107574

Da Shi , Cristoforo Demartino , Giuseppe Carlo Marano , Yongjia Xu

The performance of glue laminated bamboo (glubam) members is governed by the nonlinear response at their joints, where high deformation levels and stress concentrations are developed. Numerous phenomenological models are presently employed to describe the hysteresis behavior of these joints, while these models always have an excessive number of parameters, and the physical interpretation of these parameters is often challenging. Moreover, some hysteresis models cannot capture all hysteresis features such as asymmetry, pinching, and damage. Consequently, this paper introduces a novel phenomenological-based hysteretic model named Asymmetric Pinching Damaged (APD) model, and implemented it in Abaqus by combining connector and spring elements in series or parallel. This model encompasses asymmetry, pinching, and strength degradation for bamboo joint components, with parameters that possess clear physical meanings and are readily comprehensible. This study also presented a parameter identification framework coupling the Parallel Genetic Algorithm (PGA) and Bayesian Neural Network (BNN). By merging the FE modeling and optimizing algorithms with the interactive application of ABAQUS and Python software platforms, the integrated identification framework is capable of performing multi-threaded parallel computation of finite element models considering the BNN-based uncertainty quantification, thus greatly improving the efficiency of parameter identification.

胶合层压竹（glubam）构件的性能受其接缝处非线性响应的影响，在接缝处会产生高变形水平和应力集中。目前有许多现象学模型被用来描述这些接缝处的滞后行为，但这些模型总是有过量的参数，而这些参数的物理解释往往具有挑战性。此外，一些磁滞模型无法捕捉所有磁滞特征，如不对称、捏合和损坏。因此，本文引入了一种基于现象学的新型磁滞模型，命名为非对称捏合损伤（APD）模型，并通过将连接器和弹簧元件串联或并联的方式在 Abaqus 中实现了该模型。该模型包括竹节部件的不对称、挤压和强度退化，其参数具有明确的物理含义，易于理解。这项研究还提出了一个参数识别框架，将并行遗传算法（PGA）和贝叶斯神经网络（BNN）结合起来。通过将有限元建模和优化算法与 ABAQUS 和 Python 软件平台的交互应用相结合，该集成识别框架能够在考虑基于贝叶斯神经网络的不确定性量化的前提下，对有限元模型进行多线程并行计算，从而大大提高了参数识别的效率。

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引用次数: 0

Dynamic shear modulus degradation of saturated soil analysis: From the perspective of phase field theory 饱和土壤的动态剪切模量退化分析：从相场理论的角度

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-31 DOI: 10.1016/j.compstruc.2024.107568

Yuan Yong , Sang Qiaozhi , Chen Xi

The idea of Phase Field Method (PFM) is introduced to depict the dynamic shear modulus degradation of saturated soil revealed in the undrained triaxial tests. The order parameter in PFM is adopted to govern the liquefaction process. Then the inherent and generalized constitutive relation among shear stress, shear strain, shear modulus and confining pressure is derived. It more complies to thermodynamics in comparison to conventional empirical model following a phenomenological description. By comparing to existed empirical model, the presented four-parameter model is validated to be of robustness and efficacy to various soil types and confining pressure levels under monotonic and cyclic loading. The simulated pore pressure varies simultaneously with modulus degradation, which is consistent with observations and energy consideration. The presented method makes it possible to apply to deformation prediction in deep excavation and other engineering practice, whilst without loss of physical interpretations.

引入了相场法（PFM）的概念，以描述在不排水三轴试验中揭示的饱和土壤的动态剪切模量退化。PFM 采用阶次参数来控制液化过程。然后推导出剪应力、剪应变、剪切模量和约束压力之间固有的广义构成关系。与采用现象学描述的传统经验模型相比，该模型更符合热力学。通过与现有的经验模型进行比较，验证了所提出的四参数模型在单调和循环加载下对各种土壤类型和约束压力水平的稳健性和有效性。模拟孔隙压力与模量退化同时变化，这与观测结果和能量考虑是一致的。所提出的方法可用于深层挖掘和其他工程实践中的变形预测，同时又不失物理解释。

引用次数: 0

An objective minimal constraint formulation for the analysis of elastic articulated structures 用于分析弹性铰接结构的目标最小约束公式

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-30 DOI: 10.1016/j.compstruc.2024.107571

L. Greco, D. Castello, M. Cuomo

An implicit formulation for cylindrical joints (pivots) connecting slender rods in large deformations is presented exploiting the G¹ map at the beam's end. The rotation at the end of the rod is decomposed in the rotation of the pivot axis and a rotation around this axis. A mixed variational formulation that uses the spherical linear interpolation for the rotations is implemented. It allows to effectively model both rigid and elastic mechanisms. The proposed formulation is applied to several examples ranging from spherical scissor mechanism to elastic deployable structures that exploit the onset of instability for achieving the target shape.

利用梁端 G1 图，提出了在大变形情况下连接细杆的圆柱形接头（枢轴）的隐式计算方法。杆端旋转分解为枢轴的旋转和绕枢轴的旋转。使用球形线性插值对旋转进行混合变分计算。它可以有效地对刚性和弹性机构进行建模。所提出的公式被应用于几个例子，从球形剪刀机构到利用不稳定性的发生来实现目标形状的弹性可部署结构。

引用次数: 0

Energy-preserving matrix perturbation theory for coupling dynamic analysis of flexible structures 用于柔性结构耦合动态分析的能量守恒矩阵扰动理论

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-30 DOI: 10.1016/j.compstruc.2024.107572

Han Fei , Wu Lei , Li Shiyang , Deng Zichen , Wu Fa

Aiming at the reanalysis problem of time-varying eigenvalues of force-shape coupled systems, this paper proposes an energy-preserving matrix perturbation theory (EPMPT) that can maintain the essential physical properties of the system. The classical matrix perturbation method, which employs interpolated shape functions, fails to evaluate and address solution errors promptly during the continuous perturbation process. This limitation has led to the theoretical issue of “eigenvalue drift”, a flaw that has persisted in the original method since its introduction 40 years ago. In contrast, the presented method uses the dynamic stiffness method to obtain the system eigenvalues and eigenvectors at one time, and provides a perturbation solution to the time-varying eigenvalue problem. Further combined with the J count test technology in the Wittrick-Williams algorithm, an energy-preserving method that can “self-check and self-correct” the solution was developed. The idea that “continuous perturbation should maintain force-shape dynamic self-consistency in the frequency domain” is proposed, and avoiding the energy dispersion and resulting distortion problems caused by long-term numerical simulation. To illustrate the advantage of the EPMPT, a thermally induced vibration of an aerospace structure including force-shape coupling effect, and the vibration of a flexible space solar power arrays including rigid-flexible coupling effect are investigated. Case studied elucidates that EPMPT possesses the capability to notably enhance the computational efficiency associated with generalized eigenvalue and response reanalysis problems. When juxtaposed against conventional step-by-step integration methods, EPMPT has been found to augment computational efficiency by a margin of at least 70 %, and in some instances, up to 90 %.

针对力-形耦合系统时变特征值的再分析问题，本文提出了一种能保持系统基本物理特性的能量保护矩阵扰动理论（EPMPT）。经典的矩阵扰动方法采用插值形状函数，在连续扰动过程中无法及时评估和处理解误差。这一局限性导致了理论上的 "特征值漂移 "问题，而这一缺陷自 40 年前原始方法问世以来就一直存在。相比之下，本文提出的方法利用动态刚度法一次性获得系统特征值和特征向量，并提供了时变特征值问题的扰动解。进一步结合 Wittrick-Williams 算法中的 J 计数测试技术，开发出了一种可以 "自我检查和自我修正 "解的能量保护方法。提出了 "连续扰动应在频域内保持力形动态自洽性 "的观点，避免了长期数值模拟造成的能量分散和由此产生的失真问题。为了说明 EPMPT 的优势，研究了包含力-形耦合效应的航空航天结构热诱导振动和包含刚-柔耦合效应的柔性空间太阳能电池阵列振动。案例研究表明，EPMPT 能够显著提高与广义特征值和响应再分析问题相关的计算效率。与传统的逐步积分法相比，EPMPT 的计算效率至少提高了 70%，在某些情况下甚至高达 90%。

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引用次数: 0

A parallel geometric contact algorithm for thin shell finite elements in explicit time integration 显式时间积分薄壳有限元并行几何接触算法

IF 4.4 2区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Structures

Pub Date : 2024-10-30 DOI: 10.1016/j.compstruc.2024.107567

Qingquan Wang, Carlos Pantano

While numerical physical models of contact mechanics have become increasingly prevalent, the implementation of these models to efficiently resolve geometric contact with a robust contact search strategy remains lacking. Our research endeavors to address this gap by introducing a comprehensive solution with an exact geometric contact mechanics algorithm for thin shell finite elements with an explicit time scheme. The method has several key features, including precise geometrical resolution of self-contact interactions enabled by a sub-time-step marching method, adaptive data structures to minimize computational overhead, and a dedicated parallelization implementation with load-balancing capability. An efficient detection algorithm is implemented to reduce the natural polynomial time complexity of the problem by decomposing it into two phases: global and local phase contact detection. The impact equations are then applied to resolve the contact event by enforcing the conservation of kinematic energy and momentum. This contact algorithm is fully integrated with the MPI-based parallelization of the thin-shell finite element solver to ensure even load-balancing. The robustness and correctness of the algorithm is demonstrated in three numerical studies. Additionally, a strong scaling study showcases the scalability of the parallelization associated with the algorithm.

虽然接触力学的数值物理模型已变得越来越普遍，但仍缺乏实施这些模型来有效解决几何接触问题的强大接触搜索策略。我们的研究致力于解决这一问题，为薄壳有限元引入了一种具有显式时间方案的精确几何接触力学算法的综合解决方案。该方法有几个主要特点，包括通过子时间步进方法实现自接触相互作用的精确几何分辨率、自适应数据结构以最大限度地减少计算开销，以及具有负载平衡能力的专用并行化实现。通过将问题分解为两个阶段：全局和局部相位接触检测，实现了一种高效的检测算法，从而降低了问题的自然多项式时间复杂性。然后应用冲击方程，通过强制执行运动能量和动量守恒来解决接触事件。该接触算法与基于 MPI 的薄壳有限元求解器并行化完全集成，以确保负载平衡。三项数值研究证明了该算法的稳健性和正确性。此外，一项强大的扩展研究展示了与该算法相关的并行化的可扩展性。

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引用次数: 0