Rui F. Silva , Pedro G. Coelho , Fábio M. Conde , Bernardo R. Santos , João P. Oliveira
{"title":"Minimizing the maximum von Mises stress of elastic continuum structures using topology optimization and additively manufactured functionally graded materials","authors":"Rui F. Silva , Pedro G. Coelho , Fábio M. Conde , Bernardo R. Santos , João P. Oliveira","doi":"10.1016/j.compstruc.2024.107469","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107469","url":null,"abstract":"<div><p>The rising cost of natural resources and environmental concerns motivate systematic design and manufacture of more efficient structures. For that purpose, topology optimization has been appealing, as well as working on an enlarged design space to include multi-material solutions. The resulting optimal designs can be materialized using multi-material additive manufacturing. In the present framework, multi-material printed parts or layouts can be envisaged as having better strength properties than single-material counterparts.</p><p>The maximum von Mises stress is minimized inside a design domain through topology changes and material selection. The selected composite material model encompasses either the classical arrange of two discrete materials with sharp interfaces, or their mixture controlled by the volume fraction of each base material to generate a Functionally Graded Material (FGM). An optimized continuous variation of properties makes the FGM appealing to mitigate stress concentrations. To adequately capture the physics of mixtures considering the FGM’s mechanical properties, one uses the RAMP interpolation scheme within the Hashin-Shtrikman bounds.</p><p>A set of plane stress benchmarks are proposed. It is shown that considerably lower stress peaks on the evaluated structures can be obtained on the account of introducing more than one solid phase, specifically in the case of FGM solutions.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924001986/pdfft?md5=024fdc9c822289d483844d8ba4f73e7a&pid=1-s2.0-S0045794924001986-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141594824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Topology optimization design for strengthening locally damaged structures: A non-gradient directed evolution method","authors":"Ping Yuan , Yafu Cai , Biqin Dong , Lei Wang","doi":"10.1016/j.compstruc.2024.107458","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107458","url":null,"abstract":"<div><p>Existing non-gradient topology optimization algorithms require numerous objective function evaluations for reinforcement design of damaged structures, resulting in huge computational costs. In this study, a non-gradient directed evolution (NGDE) topology optimization method is proposed for strengthening locally damaged RC structures. First, a topology description strategy for reinforcement material (RM) component is developed to reduce the number of design variables. Then, a directed generation criterion of RM samples is given by locating the regions with the maximum concrete damage from the previous iteration step. Subsequently, the random disturbance operation, incorporating mutation, crossover, and selection, is employed to enhance the diversity of RM samples. On this basis, the element removal and size adjustment strategies of RM components are presented to overcome the numerical instability. Finally, the applicability and effectiveness of the proposed method is illustrated by the numerical examples. Results show that the proposed method can effectively generate a reasonable RM configuration for strengthening damaged RC structures without relying on design sensitivity.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-efficient complex eigen-solution algorithms for transcendental dynamic stiffness formulations of plate built-up structures with frequency-dependent viscoelastic models","authors":"Xiao Liu , Xiang Liu , Tao Lu , Dalun Tang","doi":"10.1016/j.compstruc.2024.107456","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107456","url":null,"abstract":"<div><p>Two highly accurate and reliable eigen-solution techniques, the new homotopy perturbation method and the extended argument principle method, are proposed for analysing orthotropic viscoelastic plate built-up structures. These techniques are formulated to solve transcendental eigenvalue problems in modal analysis based on the analytical damped dynamic stiffness formulations. The homotopy perturbation method uses undamped real-valued eigenvalues and eigenvectors computed by the Wittrick-Williams algorithm as the exact initial solutions. The internal damping coefficient and external damping coefficient are set as convergence control parameters by using the homotopy method, and the initial solutions are updated through inverse iteration to efficiently obtain the final complex eigenvalues. Conversely, the extended argument principle method utilizes the dichotomy of mode count in the complex domain, based on the denominators of elemental dynamic stiffness matrices, to pinpoint complex eigenvalues. Validation against finite element solutions from COMSOL shows that while the extended argument principle method offers benchmark solutions, it is computationally intensive. In contrast, the proposed homotopy perturbation method presents a valuable tool in engineering applications due to its exceptional balance of accuracy and computational efficiency. This method facilitates rapid analyses and design parameter optimization within the context of viscoelastic plate structures.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sima Rishmawi , Sebastian Rodriguez , Francisco Chinesta , Frédérick P. Gosselin
{"title":"Harmonic-modal hybrid frequency approach for parameterized non-linear dynamics","authors":"Sima Rishmawi , Sebastian Rodriguez , Francisco Chinesta , Frédérick P. Gosselin","doi":"10.1016/j.compstruc.2024.107461","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107461","url":null,"abstract":"<div><p>Structural dynamics systems are represented by discretized partial differential equations, whose solutions depend on various parameters. Developing high-fidelity numerical models for multi-dimensional systems or those with multiple parameters can be computationally expensive, particularly if the systems are non-linear. Consequently, the concept of a precalculated library of the system's response to a wide range of parameters is appealing. Thus, a global non-linear space-frequency solver is proposed that produces a low-rank representation of the solution using Modal Basis analysis known as the Harmonic Modal Hybrid Method. The DEIM is also used to accelerate its convergence by creating a reduced basis of the non-linear function(s) based on either calculated or experimental values. The optimized solver is then employed for rapid offline computations to construct surrogate models that can give real-time predictions of the parametrized dynamic response using the sPGD technique. These models serve as building blocks for virtual twins that necessitate near-instantaneous calculations when the system parameters and/or conditions are changed. A proof of concept is illustrated by using this technique to analyze a well-known non-linear system, the cantilevered beam with a non-linear cubic spring attached to its end. This method can be easily extended to solve other dynamical systems quickly and effectively.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analyzing material softening and strain localisation through embedded strong discontinuity approach within velocity-based beam formulation","authors":"Sudhanva Kusuma Chandrashekhara, Dejan Zupan","doi":"10.1016/j.compstruc.2024.107464","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107464","url":null,"abstract":"<div><p>In this paper, we propose a novel computational formulation capable of solving the problem of material softening and the emerging localisation of strains in spatial frame-like structure, a common phenomenon for brittle heterogeneous materials. This study adopts the embedded strong discontinuity approach within our original velocity-based framework. The velocity-based formulation is thus enhanced with additional capabilities of detection of critical load level and critical cross-section and introduction of the jump-like variables at the level of velocities and angular velocities to enable more realistic description of strain localisation. A modified consistency condition is derived using the method of weighted residuals in complete accordance with the theoretical concept of strong discontinuity. One of the key advantages of the proposed method is its computational efficiency, which is preserved even after detecting cross-sectional singularities and handling post-critical localised strains. The numerical examples show the effectiveness and robustness of the proposed approach.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924001937/pdfft?md5=c8b854e0e6b8b7f1968ca429787ec759&pid=1-s2.0-S0045794924001937-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanbo Zhang , Zhenhai Liu , Chengxuan Li , Hongfei Ye , Hongwu Zhang , Hui Li , Yonggang Zheng
{"title":"A stabilized peridynamic correspondence material model for axisymmetric ablation and fracture problems","authors":"Hanbo Zhang , Zhenhai Liu , Chengxuan Li , Hongfei Ye , Hongwu Zhang , Hui Li , Yonggang Zheng","doi":"10.1016/j.compstruc.2024.107467","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107467","url":null,"abstract":"<div><p>A stabilized peridynamic correspondence material model for axisymmetric problems (SPD-CMM-A) is proposed in this work to effectively simulate the ablation and ductile fracture behaviors of metals under high temperatures. To quantify the damage resulting from compression and shearing deformations, a strain energy density decomposition method is incorporated into the ductile damage model. Furthermore, a novel axisymmetric stabilization method based on peridynamics linearization theory is introduced to mitigate numerical oscillations arising from zero-energy modes in both thermal and mechanical scenarios. To capture the varying geometries and update the boundary conditions during ablation, a moving boundary model is developed based on temperature-associated criteria. To validate the capacity of the proposed SPD-CMM-A, several representative numerical experiments are conducted. These examples not only affirm its ability to stabilize numerical oscillations in coupled axisymmetric thermoplastic problems but also demonstrate its capability for accurately simulating ablation and predicting crack propagation.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Da Shi , Giuseppe Carlo Marano , Cristoforo Demartino
{"title":"Bio-based connections and hybrid planar truss: A parallel genetic algorithm approach for model updating","authors":"Da Shi , Giuseppe Carlo Marano , Cristoforo Demartino","doi":"10.1016/j.compstruc.2024.107463","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107463","url":null,"abstract":"<div><p>Bolted steel to laminated bio-based material connections experience significant performance challenges due to the nonlinear response and high stress concentrations at their joints. This paper introduces an innovative 3D plasticity-fracture continuum Finite Element (FE) model that significantly advances the simulation of such truss joints by integrating Hill's yielding criteria with an element removal methodology for fracture simulation. This novel approach captures both plastic and fracture behaviors simultaneously, a capability not sufficiently addressed in existing models. We detail the theoretical framework for these models, including the derivation of constitutive equations and the algorithms necessary for their implementation in ABAQUS. Additionally, it is provided a low-fidelity modeling of truss joints, offering a comprehensive analysis of connector elements, joint models, and parametric modeling via Python scripting. The model's efficacy is demonstrated through identification of connection and of hybrid planar trusses under cyclic loading, which validates the practical applicability of the method. To optimize computational efficiency, we developed a Parallel Genetic Algorithm (PGA) that integrates seamlessly with ABAQUS and Python to facilitate parameter calibration. This integration not only enhances the model's accuracy but also reduces computational load, making it feasible for complex engineering applications. Our findings illustrate a significant improvement in modeling accuracy and efficiency, establishing a robust methodology for analyzing truss joints in bio-based construction materials.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas E. Silionis, Theodora Liangou, Konstantinos N. Anyfantis
{"title":"Deep learning-based surrogate models for spatial field solution reconstruction and uncertainty quantification in Structural Health Monitoring applications","authors":"Nicholas E. Silionis, Theodora Liangou, Konstantinos N. Anyfantis","doi":"10.1016/j.compstruc.2024.107462","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107462","url":null,"abstract":"<div><p>In recent years, increasingly complex computational models are being built to describe physical systems which has led to increased use of surrogate models to reduce computational cost. In problems related to Structural Health Monitoring (SHM), models capable of handling both high-dimensional data and quantifying uncertainty are required. In this work, our goal is to propose a conditional deep generative model as a surrogate aimed at such applications and high-dimensional stochastic structural simulations in general. To that end, a conditional variational autoencoder (CVAE) utilizing convolutional neural networks (CNNs) is employed to obtain reconstructions of spatially ordered structural response quantities for structural elements that are subjected to stochastic loading. Two numerical examples, inspired by potential SHM applications, are utilized to demonstrate the performance of the surrogate. The model is able to achieve high reconstruction accuracy compared to the reference Finite Element (FE) solutions, while at the same time successfully encoding the load uncertainty.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141542235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jerneja Češarek Kolšek, Igor Planinc, Sebastjan Bratina
{"title":"A novel family of strain-based finite elements for the analysis of the material softening of planar frames","authors":"Jerneja Češarek Kolšek, Igor Planinc, Sebastjan Bratina","doi":"10.1016/j.compstruc.2024.107442","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107442","url":null,"abstract":"<div><p>The article presents a novel strain-based finite element family for the analysis of material softening of planar frame structures. In our case, the softening zone is described by a discrete crack, which is considered as an ‘excluded’ finite element point, i.e., the deformation quantities in the crack are considered separately from the deformation quantities of the element. They are connected to the element only through kinematic quantities, used to describe the crack opening. The criterion for crack initiation is defined as the limit axial-bending resistance of the cross-section. The advantage of the presented model is that it is not necessary to define cracks or softening zones in advance and that the solution is mesh-independent in the sense that no further densification of the mesh is needed purely on account of capturing material softening. The accuracy and efficiency of the presented finite element family is illustrated by the example of a clamped–simply supported concrete beam and a portal concrete frame. The examples demonstrate that even with a minimum number of finite elements of suitable accuracy, sufficiently accurate results are obtained for normal engineering practice.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of the modified GTN model in predicting Taylor impact fracture of 7XXX aluminum alloy","authors":"Fanlei Min , Kunyuan Gao , Hui Huang , Shengping Wen , Xiaolan Wu , Zuoren Nie , Dejing Zhou , Xuecheng Gao","doi":"10.1016/j.compstruc.2024.107457","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107457","url":null,"abstract":"<div><p>The Gurson-Tvergaard-Needleman (GTN) model has been improved to extend its application for high strain rate loading and assessed by using the Taylor impact process of 7xxx aluminum alloys. The existing modification method based on independent shear damage variables has been integrated into the enhanced GTN model to assess shear fracture. In addition, the effects of strain rate hardening, temperature softening, and viscosity resistance terms have been taken into account in the constitutive equation to accurately depict the material’s deformation behavior under high strain rates. A series of quasi-static mechanical tests and Split Hopkinson Pressure Bar (SHPB) tests with strain rates ranging from 1000<span><math><msup><mrow><mi>s</mi></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></math></span> ∼ 5000 <span><math><msup><mrow><mi>s</mi></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></math></span> were conducted on 7A52-T6 alloy and 7A62-T6 alloy. The Taylor impact experiments showed that the mushrooming deformation and shear fractures occurred as the impact velocity increased. Both the 7A52 and 7A62 alloys exhibited fracture characteristics of shear and void nucleation, and the voids only grew slightly after formation. The predicted fracture patterns in Taylor impact and the evolution trend of material strength using the enhanced GTN model are consistent with the experimental results.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}