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Classification of inelastic deformation and material-intrinsic indices about mechanical performance of general solid matter

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Science China(Physics,Mechanics & Astronomy) 2023年第11期66卷 155-178页

作者： Yichao Zhu Shaoshuai Li Biao Wang Department of Engineering Mechanics Dalian University of TechnologyDalian116024China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian116024China School of Physics and Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityGuangzhou510275China Research Institute of Interdisciplinary Science Dongguan University of TechnologyDongguan523808China

The present article is aimed to detect material-intrinsic indices that can be used to supervise the mechanical performance of general solid *** novelty carried in this article can be summarised as ***,an inelastic deformation state of almost any solid matter can be treated as the combination of two fundamental modes due to different microscopic causation:Mode I inelastic distortion due to the movement of sliding types of defects and Mode II inelastic dilation due to the evolution of voids/***,each inelastic deformation mode is characterised by a single principal inelastic deformation descriptor(PIDD):Mode I by a newly introduced quantity of maximum distortional angle changeαand Mode II by the logarithm of dilating magnificationω.In particular,the concept of maximum distortional angle change gives rise to a geometrically intuitive yield criterion ofα>α_(c),which in situations of small deformation,is shown to asymptote von Mise's,and to become Tresca's in cases of plane ***,the deformation process of a solid matter under monotonic and ambient loads is formulated by means of trajectories of thermodynamic equilibria with respect to the PIDD *** a pair of physical quantities which measure the stresses needed to change the local PIDD state are singled *** termed as inelastic deformation resistances(IDRs),these two quantities are shown to depend only on the onsite atomic *** is also shown that key descriptive properties about the mechanical behaviours of materials,such as ductility,are encoded in IDRs as functions of *** the IDR pair may serve as material performance indices that may be more intrinsic than conventional stress-strain relationships.

关键词： inelastic deformation modes mechanical performance index thermodynamic principal inelastic deformation descriptor inelastic deformation resistance

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Modal Identification of Spatial Trusses Based on Bayesian Approach

Modal Identification of Spatial Trusses Based on Bayesian Ap...

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UNIfied Conference of International Workshop on Defence Applications of Multi-Agent Systems, DAMAS 2023, International Conference on Maintenance engineering, IncoME-V 2023, International conference on the Efficiency and Performance engineering Network, TEPEN 2023

作者： Pan, Yaozong Sun, Mingye Feng, Ying Zhao, Yan State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Faculty of Vehicle Engineering and Mechanics Dalian University of Technology Dalian116023 China Ningbo Research Institute of Dalian University of Technology Ningbo315016 China

ISBN: (纸本)9783031494208

Modal identification mainly uses the input and output data of the structure to determine the natural frequency, modal damping ratio, and mode shape of the structure. The identified dynamic properties can provide the basis for structural vibration control, model updating and structural health monitoring. In the modal identification methods, Bayesian method considers the influence of system uncertainty on modal parameter identification and gives the quantified index of system uncertainty, which is an obvious advantage of Bayesian method compared with other identification methods. Space truss is usually carried on spacecraft as a support structure, and obtaining its accurate modal parameters is important for the attitude controller design of spacecraft. In this paper, a Bayesian time-domain method is proposed and used to identify the modal parameters of a numerical model of a space truss structure. First, the structure is modeled using the state equation and the mathematical relationship between the physical response of the space truss and the modal parameters is derived based on the Markov parameter matrix;secondly, the likelihood function and the posterior probability density function of the modal parameters are established based on Bayesian theory;Finally, the most probable values of the modal parameters of the space truss structure were solved using the optimization algorithm, and the posterior covariance matrix of the parameters was solved using the finite difference method to quantify the uncertainties of the parameters. The identification results and the finite element analysis results were compared to verify the accuracy of the method in this paper. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Probability density function

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Compression-After-Impact analysis of Recyclable Epoxy Resin Matrix Composites 2

Compression-After-Impact Analysis of Recyclable Epoxy Resin ...

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2nd International Conference on New Materials, Machinery, and Vehicle engineering, NMMVE 2023

作者： Li, Qian Bai, Ruixiang Bai, Heshan Lei, Zhenkun Li, Xuwei Yan, Cheng State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Dalian University of Technology China School of Chemistry Physics and Mechanical Engineering Science and Engineering Faculty Queensland University of Technology BrisbaneQLD4001 Australia

ISBN: (纸本)9781643684208

Traditional thermoset composites were difficult to remodel and recycle after curing, which significantly increased the cost of composites. In response to these difficulties, the booming development of bond exchange reactive resins have provided a new direction for composites. Traditional composites were vulnerable to damage under low-velocity impact loading, which led to the failure of the overall structure, however, the research on the impact damage of recyclable resins was still insufficient. In order to investigate the damage form of recyclable epoxy resin matrix composites under impact loading, a macroscopic low-velocity impact (LVI) and compression-after-impact (CAI) model based on ABAQUS/Explicit considering the interaction between matrix and fiber damage in composites was established. The paper adopted a multi-scale simulation framework, focusing on the influence of matrix elastic parameters on the structure, and predicted the effective elastic parameters of the matrix composite by constructing a preliminary microscopic representative volume element model. Subsequently, the complex damage modes of laminates at various impact energies and the damage failure mechanism after compression were investigated. © 2023 The authors and IOS Press.

关键词： Epoxy resins

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Transfer Learning-Based Image Processing of Recognizing Office Objects for Indoor Mobile Robots 8

Transfer Learning-Based Image Processing of Recognizing Offi...

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8th IEEE International Conference on Advanced Robotics and Mechatronics, ICARM 2023

作者： Gong, Ze Su, Longfei Liu, Hongshuo Gu, Yao Yue, Ming School of Automotive Engineering Dalian University of Technology Dalian116024 China Dalian University of Technology State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Dalian116024 China

ISBN: (纸本)9798350300178

This paper proposes an OpenCV-based image processing method and a target recognition approach for indoor office mobile robots based on transfer learning. Firstly, the recognized image is pre-processed for clarity to remove the effect of uneven lighting;secondly, the transfer learning idea is introduced to extract image features, then the study modifies the fully connected layer of the Resnet18 network and trains the network model parameters;finally, the trained network model is used to conduct target recognition experiments on the pre-processed image. The experimental results show that the method can effectively recognize the images of items in indoor office mobile robots with relatively high accuracy and efficiency. © 2023 IEEE.

关键词： Mobile robots

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Variable-fidelity optimization method with dynamic search space reduction for variable stiffness composite cylinders

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Composite Structures 2025年 370卷

作者： Tian, Kuo Sun, Zhiyong Gao, Tianhe Liu, Chong Department of Engineering Mechanics State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Dalian University of Technology Dalian116024 China

Incorporating multiple manufacturing constraints leads to a highly nonlinear and non-convex feasible design space for variable stiffness composite (VSC) cylinders, significantly increasing the difficulty and computational cost associated with achieving optimization design. To enhance the global optimization capability within this complex constrained design space, a novel variable-fidelity surrogate model with dynamic search space reduction (VFSM-DSSR) is introduced in this paper. Firstly, a mathematical description method of multiple manufacturing constraints is presented for VSC cylinders to ensure the manufacturability of fibers, establishing the constraint conditions for subsequent optimization. Particularly, the fiber path divergence formula for cylindrical structures is derived for the first time. Furthermore, an optimization framework based on VFSM-DSSR is established consisting of a two-stage search space reduction strategy. In the first stage, a pre-screening of search space is carried out using the Fuzzy C-means Clustering algorithm and a low-fidelity surrogate model. This allows for a rapid identification of the high-potential search space while considering multiple constraints. Subsequently, in the second stage, a local high-precision VFSM is constructed within the initial reduced search space. Then, a dynamic search space reduction strategy is introduced through search space shifting and scaling, which helps avoid falling in local optima and enhance the global optimization capability. Finally, to verify the effectiveness of the proposed method, an optimization example of a VSC cylinder under multiple manufacturing constraints is conducted. Results indicate that with comparable computational cost, the VFSM-DSSR method achieves a significant improvement in the buckling load of the VSC cylinder. Specifically, it outperforms the direct surrogate-based optimal result within the original design space by over 22.22%. © 2025 Elsevier Ltd

关键词： Clustering algorithms

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Stochastic seismic responses and dynamic reliability analysis of long-span cable-stayed bridge with multi-dimensional isolation and energy dissipation devices

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Soil Dynamics and Earthquake engineering 2025年 197卷

作者： Liu, Jinlei Li, Hui Zhang, Yu Chen, Guohai Yang, Dixiong State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian116024 China

To assess the seismic performance of long-span cable-stayed bridge with multi-dimensional isolation and energy dissipation (MIED) devices, a unified and adaptive framework for determining efficiently stochastic seismic responses and dynamic reliabilities via direct probability integral method (DPIM) is proposed. Moreover, to reduce the effects of near-fault ground motions, a superior MIED scheme is devised by comparative analysis in multiple conditions. Firstly, based on the probability density integral equation, the formulas for calculating time-variant statistical moments of responses and dynamic reliabilities in the component level and the system level are derived. Then, DPIM with fully adaptive strategy is suggested to calculate the stochastic seismic responses and dynamic reliability of cable-stayed bridge with MIED devices more accurately and efficiently than Quasi-Monte Carlo simulation. The comparative study indicates that the superior MIED scheme combines lateral elastoplastic cable pairs with longitudinal fluid viscous dampers (CP-FVD) in pylon-girder connection. CP-FVD system can reduce bending moments of pylons in lateral and longitudinal directions and displacement of the pylon-girder connection. The velocity pulses of near-fault ground motions lead to large seismic responses and failure probability of the bridge. Finally, the structural responses and reliabilities in the component level and the system level are remarkably affected by wave propagation speed. © 2025 Elsevier Ltd

关键词： Cable stayed bridges

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Research on Energy-Saving Optimization of Different Formation Configurations Based on Four Catamarans 30th

Research on Energy-Saving Optimization of Different Formatio...

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30th International Conference on Computational and Experimental engineering and Sciences, ICCES 2024

作者： Jiang, Bo Liang, Xu Wang, Longkan Zhang, Zhifan Wang, Yuemei State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment School of Naval Architecture Engineering Dalian University of Technology Dalian116024 China CSSC Systems Engineering Research Institute Beijing100080 China China Ship Research and Development Academy Beijing100192 China

ISBN: (纸本)9783031687747

Nowadays, sailing in formation has been the major trend with the rise of unmanned ships. In the past, research about unmanned catamaran formation were more focused on algorithmic control, but the changes in hydrodynamic performance and energy are often overlooked. In nature, various collective behaviors indicate that followers would obtain significant energy consumption from beneficial interaction in certain formation configurations. Based on the previous research, the high-speed catamaran delft-372 was chosen as the basic numerical model in this paper. Four ship’s formation configurations (tandem, "trimaran", and rectangle formations) are proposed to analyze the influence on the hydrodynamic performance of each ship, based on the Reynolds Averaged Navier-Stokes (RANS) method in combination with the Shear Stress Transport (SST) k-ω turbulence model. Through comparative analysis, it can be seen that the resistance and motion of the following ships have been optimized under specific formation configurations, but the impact of various formation configurations is quite different. In terms of single ship’s energy preservation, the last following ship of "trimaran" formation has the best performance. For the whole, tandem formation is the optimal fleet configuration. In conclusion, the hydrodynamic performance of four catamarans in different formation configurations has been studied, which can provide some reference significance. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Drag reduction

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Sequence-to-Sequence Multi-Hop Knowledge Reasoning Based on Retentive Network 7

Sequence-to-Sequence Multi-Hop Knowledge Reasoning Based on ...

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7th International Conference on Computer Information Science and Application Technology, CISAT 2024

作者： Su, Ruilin Zhang, Wanshan Yu, Dunhui Hubei University Wuhan China Wuhan430062 China Hubei University School of Computer Science and Information Engineering Wuhan430062 China Hubei University Hubei Key Laboratory of Big Data Intelligent Analysis and Application Wuhan430062 China Engineering and Technical Research Center of Hubei Province in Software Engineering Wuhan430062 China

ISBN: (纸本)9798350375107

Multi-hop Knowledge Reasoning is a task that involves generating an answer given a query and a knowledge graph. Existing sequence-to-sequence reasoning models use the Transformer to encode and decode sequences, but these models have some flaws, such as the inability to effectively handle long-sequence reasoning and susceptibility to exposure bias. To address these issues, we provides a sequence-to-sequence reasoning model named STSR, which is based on Retentive Network. Aiming at improving training efficiency through parallel training, this model leverages the advantages in Retentive Network, reduce time overhead, and enhance reasoning efficiency through iterative reasoning. It effectively mitigates the problems of high spatial overhead and low efficiency in long-sequence reasoning faced by the Transformer. Moreover, it retains and updates historical information during the encoding and decoding process, enhancing the model's memory and generalization capabilities. Additionally, the Scheduled Sampling method is adopted to alleviate the exposure bias introduced during reasoning, which involves using the model's own output as the input for the next moment with a certain probability during training, instead of using the true label. We conduct the experiment on six public datasets, with the results showing that the proposed model outperforms existing baseline models in terms of precision and generation quality. This paper provides a new solution for the task of sequence-to-sequence multihop knowledge reasoning and also demonstrates the potential application of the Retentive Network in natural language processing. © 2024 IEEE.

关键词： Iterative decoding

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Application of CFD and FEA Coupling to Predict Structural Dynamic Responses of A Trimaran in Uni-and Bi-Directional Waves

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China Ocean engineering 2024年第1期38卷 81-92页

作者： LIAO Xi-yu XIA Jin-song CHEN Zhan-yang TANG Qin ZHAO Nan ZHAO Wei-dong GUI Hong-bin Marine Design&Research Institute of China Shanghai 200011China Ship Structure Division China Ship Scientific Research CenterWuxi 214082China College of Ocean Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China School of Foreign Studies Jiangnan UniversityWuxi 214122China

To predict the wave loads of a flexible trimaran in different wave fields,a one-way interaction numerical simulation method is proposed by integrating the fluid solver(Star-CCM+)and structural solver(Abaqus).Differing from the existing coupled CFD-FEA method for monohull ships in head waves,the presented method equates the mass and stiffness of the whole ship to the hull shell so that any transverse and longitudinal section stress of the hull in oblique waves can be ***,verification study and sensitivity analysis are carried out by comparing the trimaran motions using different mesh sizes and time step *** on the wave elevation of uni-and bi-directional waves is also carried *** a comprehensive analysis on the structural responses of the trimaran in different uni-directional regular wave and bi-directional cross sea conditions is carried out,***,the differences in structural response characteristics of trimaran in different wave fields are *** results show that the present method can reduce the computational burden of the two-way fluid-structure interaction simulations.

关键词： CFD-FEA fluid-structure coupling structural responses trimaran bi-directional cross sea

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GraphDGM: A Generative Data-Driven Design Approach for Frame and Lattice Structures

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Journal of Mechanical Design 2025年第10期147卷 101701页

作者： Yang, Zhenling Guo, Yilin Sun, Zhi Elkhodary, Khalil I. Feng, Fuyong Kang, Zhong State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian116023 China International Research Center for Computational Mechanics Dalian University of Technology Dalian116023 China The Department of Mechanical Engineering The American University in Cairo New Cairo11835 Egypt China North Artificial Intelligence & Innovation Research Institute Beijing100072 China Collective Intelligence & Collaboration Laboratory Beijing100072 China China North Vehicle Research Institute Beijing100072 China

Generative artificial intelligence offers a more efficient solution for the design of structures. However, an inverse generation of structures, which meet multiple design objectives, remains an open problem. This article thus focuses on the inverse design of frame structures and proposes Graph-based Diffusion-Generative Multiobjective design (GraphDGM), a graph-based generative data-driven surrogate model constrained by multiple targets. By integrating the finite element method (FEM), we construct datasets of frame structures subjected to various conditions. We then developed a conditional graph generation model based on the denoising diffusion probabilistic models (DDPM) and the attention mechanism. We show that our method can efficiently accomplish the inverse design of various frame structures, including a vehicle’s skeleton subjected to five simultaneous constraints. Furthermore, we present comparative experiments against baseline methods to demonstrate the effectiveness and superiority of the GraphDGM. Copyright © 2025 by ASME.

关键词： Inverse problems

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