Article
Materials Science, Multidisciplinary
Arefeh Abbasi, Dong Yan, Pedro M. Reis
Summary: This study focuses on the mechanical response of pressurized spherical shells with a single dimple-like defect to a point probe, characterizing the nonlinear force-indentation response at different pressurization levels through experiments, finite element modeling, and classic shell theory. The critical buckling pressure of the shell can be inferred non-destructively by tracking the maxima of the indentation force-displacement curves, with the effectiveness of probing influenced by the indentation angle. The study also quantifies the characteristic length associated with localized deformation using FEM simulations and shallow shell theory, demonstrating the limitations of applying probing as a non-destructive technique to assess the stability of spherical shells.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Mathematics, Applied
Davit Harutyunyan, Andre Martins Rodrigues
Summary: This study proves that the buckling load of cylindrical shells under vertical compression depends on the curvature of the cross section curve. For convex curves with uniformly positive curvature, the buckling load has a linear relationship with the shell thickness. For curves with positive curvature at finitely many points, the buckling load lies between C(1)h(8/5) and C(2)h(3/2) for small thickness h > 0.
JOURNAL OF NONLINEAR SCIENCE
(2023)
Article
Mechanics
Zbigniew Kolakowski, Andrzej Teter
Summary: The behavior of FGM cylindrical shells with imperfections under compression was analyzed using an analytical-numerical method. The critical load and imperfection sensitivity surface of real structures were determined. The material gradient and support conditions of the shell were taken into account in the calculations. This research provides insights for the design and verification of shell structures.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Multidisciplinary
Haoran Wang, Johann Guilleminot, Benjamin W. Schafer, Mazdak Tootkaboni
Summary: Buckling of thin-shell structures is a classic problem in mechanics. In this study, we investigate the buckling behavior of imperfect cylindrical shells using a novel representation of the stochastically imperfect shell geometry. Through finite element analysis, we gain new insights into the interplay between random imperfections and topological features that influence buckling behavior.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Tianzhen Liu, Yuzhen Chen, John W. Hutchinson, Lihua Jin
Summary: Viscoelastic spherical shells exhibit a wide range of time/rate-dependent buckling behaviors, including creep buckling, which occurs after a time delay. This study develops an analytical model to understand the nonlinear time-dependent buckling behavior of these shells, considering geometric imperfections and two types of loading: prescribed rate of volume change and constant pressure. The results demonstrate the important roles of viscoelasticity and loading rates in the load-carrying behavior, and reveal a connection between short-time elastic buckling and long-time creep buckling limits.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Review
Chemistry, Physical
Domenico Magisano, Francesco Liguori, Antonio Madeo, Leonardo Leonetti, Giovanni Garcea
Summary: Optimizing the response of composite thin-walled structures prone to buckling is crucial for engineering applications, and recent computational developments have shown how to transform unstable structures into stable ones. Various aspects such as mechanical models, material parametrization, solution methods, and structural optimization algorithms are discussed, with a numerical example provided to illustrate optimal material design.
Article
Engineering, Civil
Mariano Victoria, Concepcion Diaz, Pascual Marti, Osvaldo M. Querin
Summary: This paper presents an extension to the Isolines Topology Design (ITD) algorithm for the topology design of 2D continuum structures under the influence of buckling. The alternative approach incorporates the buckling effect by transforming the buckling topology optimization problem into a stress-based topology design problem. The effectiveness of the new approach is demonstrated through three examples, showing good agreement with existing literature.
Article
Engineering, Multidisciplinary
H. N. R. Wagner, G. Niewoehner, A. Pototzky, C. Huehne
Summary: This article reviews experimental results of tori-spherical shells under external pressure, presents detailed numerical elastic-plastic buckling analysis and various geometric imperfection approaches, leading to the development of new design factors that significantly improve critical load estimations.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Construction & Building Technology
Lin Zhao, Zhenggang Cao, Jinxing Feng, Xiao Hu, Feng Fan
Summary: With the promotion of green construction, the use of prefabricated single-layer reticulated shells (PSLRS) with assembled joints in large-span buildings has increased. However, joint assembly errors during manual installation can weaken the mechanical properties of joints and affect the overall stability of PSLRS. This paper studied the adverse effects of joint assembly errors on the flexural performance and stability bearing capacity of PSLRS. The research proposed methods to estimate reliable bearing capacity and obtained valuable insights for the structural design of PSLRS.
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Wenguang Gu, Haigui Fan, Longhua Li, Zewu Wang, Peiqi Liu, Dapeng Hu
Summary: In this paper, a promising buckling design method for composite cylindrical shells is proposed and its reliability and advantages are verified through experiments. The study also reveals the significant impact of laminate stacking angles on the design buckling loads.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Construction & Building Technology
Masaki Teranishi, Koichiro Ishikawa
Summary: In this study, 64 types of single-layer latticed domes with different geometric properties were optimized to obtain mechanically effective grid patterns. The geometric and mechanical properties of the optimized grid patterns were quantitatively evaluated, showing that the optimized grid pattern had superior mechanical properties. The optimization scheme can be applied for designing mechanically effective grid patterns for single-layer latticed domes.
ADVANCES IN STRUCTURAL ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Shiying Chen, Weiguo Li, Jin Quan, Qing Li
Summary: In this study, a novel optimization method was proposed to improve the stability and bearing capacity of grid shell structures. By comparing with the conventional method, it was found that the proposed method resulted in higher stable carrying capacity and lower sensitivity. Moreover, this method is efficient and convenient for unskilled designers.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Multidisciplinary Sciences
Abubakr E. S. Musa, Madyan A. Al-Shugaa, Husain J. Al-Gahtani
Summary: Buckling is the most common type of failure for circular cylindrical shells subjected to axial compressive forces. The buckling stress of these shells is highly affected by geometric imperfections, such as localized damage (dents), which significantly reduce the buckling strength. This study numerically investigates the effect of dent imperfections on the buckling strength of shells with large R/t ratios, finding that dent size, depth, and position do not show a remarkable trend in their relationship with the reduction in buckling strength.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Mechanics
Xinhu Zhang, Zhun Li, Zhaoqi Yang, Leilei Jiang, Guang Pan
Summary: This paper investigates the buckling problems of composite shells with initial imperfections under hydrostatic pressure. A novel initial imperfection model is introduced, and analytical solutions are derived based on Sanders-type kinematic relations. The numerical examples show that proper control of initial imperfection parameters can significantly improve the critical buckling pressure, which is valuable for practical design of composite pressure hulls.
COMPOSITE STRUCTURES
(2022)
Review
Engineering, Mechanical
Bo Wang, Peng Hao, Xiangtao Ma, Kuo Tian
Summary: Thin-walled structures are commonly used in aerospace and aircraft structures, but accurately predicting the lower-bound buckling load is still a challenge due to geometric imperfections. This paper reviews several new numerical and experimental methods for determining knockdown factors (KDF) and proposes an improved KDF curve based on extensive test data. The new KDFs show an overall improvement compared to the traditional criterion.
ACTA MECHANICA SINICA
(2022)
Article
Robotics
Gaia Pavoni, Massimiliano Corsini, Federico Ponchio, Alessandro Muntoni, Clinton Edwards, Nicole Pedersen, Stuart Sandin, Paolo Cignoni
Summary: Semantic segmentation is a widely-used image analysis task, and deep learning-based approaches have the potential to significantly reduce manual annotation time. However, current automated solutions may not meet expert standards. TagLab is introduced as an interactive tool that speeds up semantic segmentation by integrating multiple degrees of automation to empower human capabilities. Through a user study on coral community segmentation, TagLab demonstrated a 90% increase in annotation speed for nonexpert annotators without compromising labeling accuracy, and improved fully automatic predictions by 7% on average and by 14% in challenging cases. Preliminary investigations also suggest further significant reductions in annotation times.
JOURNAL OF FIELD ROBOTICS
(2022)
Article
Computer Science, Software Engineering
Nico Pietroni, Marcel Campen, Alla Sheffer, Gianmarco Cherchi, David Bommes, Xifeng Gao, Riccardo Scateni, Franck Ledoux, Jean Remacle, Marco Livesu
Summary: In this article, a comprehensive survey of hexahedral mesh generation techniques is provided, covering various approaches, post-processing algorithms, and associated challenges. The discussion also includes recent relaxed approaches for hex-dominant mesh generation. The required background knowledge in geometry and combinatorial aspects is introduced.
ACM TRANSACTIONS ON GRAPHICS
(2023)
Article
Humanities, Multidisciplinary
Gaia Pavoni, Francesca Giuliani, Anna de Falco, Massimiliano Corsini, Federico Ponchio, Marco Callieri, Paolo Cignoni
Summary: This article explores the potential of AI-based solutions to improve the efficiency of masonry annotation in Architectural Heritage, aiming to provide interactive tools that support and empower the current workflow.
ACM JOURNAL ON COMPUTING AND CULTURAL HERITAGE
(2022)
Article
Engineering, Civil
Francesco Laccone, Luigi Malomo, Marco Callieri, Thomas Alderighi, Alessandro Muntoni, Federico Ponchio, Nico Pietroni, Paolo Cignoni
Summary: Mesostructured patterns refer to a concept of designing the geometry of structural material at the meso-scale to achieve desired mechanical performances. This paper introduces a new constructional system called FlexMaps, which adopts bending-active mesostructures at the architectural scale. The system utilizes CNC-milled plywood panels in the form of four-arms spirals and seamlessly links all phases from conceptual design to fabrication within an automated workflow. The paper showcases the potential of the system through a demonstrator project and evaluates its structural response and long-term behavior through detailed analysis and survey.
JOURNAL OF THE INTERNATIONAL ASSOCIATION FOR SHELL AND SPATIAL STRUCTURES
(2022)
Article
Computer Science, Software Engineering
T. Alderighi, L. Malomo, T. Auzinger, B. Bickel, P. Cignoni, N. Pietroni
Summary: In this article, the authors review the automatic methods for the design of moulds, focusing on contributions from a geometric perspective. They classify existing mould design methods based on their computational approach and the nature of their target moulding process. The relationships between computational approaches and moulding techniques are summarized, and potential future research directions are discussed.
COMPUTER GRAPHICS FORUM
(2022)
Article
Computer Science, Interdisciplinary Applications
Francesco Laccone, Domenico Gaudioso, Luigi Malomo, Paola Cignoni, Maurizio Froli
Summary: In the context of tall building design, the use of the tube concept and the diagrid pattern has been efficient in providing structural support. However, to improve the architectural impact and aesthetic appeal, alternative geometries such as Voronoi mesh are gaining interest. This paper introduces a method called Vorogrid, which modifies the Voronoi mesh to create a more organic-looking and mechanically sound tube structure, offering design control and better average performances compared to random Voronoi structures.
COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING
(2023)
Article
Computer Science, Software Engineering
A. Maggiordomo, P. Cignoni, M. Tarini
Summary: We propose a technique that removes texturing artefacts in 3D models acquired using photogrammetry. Our technique utilizes recent advancements in inpainting of natural colour images and adapts them to the specific context. By employing a modified and trained neural network, we replace the defective texture areas with plausible patches of texels reconstructed from the surrounding surface texture. The method has two applications: a fully automatic tool that addresses all problems detected by analyzing the UV-map of the input model, and an interactive semi-automatic tool presented as a 3D 'fixing' brush that removes artefacts from any user-painted zone.
COMPUTER GRAPHICS FORUM
(2023)
Article
Computer Science, Software Engineering
Louis Pratt, Andrew Johnston, Nico Pietroni
Summary: This paper presents a new method for generating artworks using freeform reflective and refractive media and 3D surfaces instead of images. The method combines raytracing and surface deformation techniques to determine the proper deformation needed to correct the object's appearance when viewed in a specific location. An optimization process is also included to avoid unwanted optical effects or occlusions. The technique has been successfully tested on practical examples and used to create actual artworks.
COMPUTERS & GRAPHICS-UK
(2023)
Article
Engineering, Civil
Yuanpeng Liu, Ting-Uei Lee, Antiopi Koronaki, Nico Pietroni, Yi Min Xie
Summary: Space frame structures are favored in contemporary free-form architectural designs for their elegant appearance and excellent structural performance. However, the use of different shaped nodes in doubly-curved space frame structures leads to high manufacturing costs. In this study, a new clustering-optimization framework is proposed to reduce the variety of node shapes, achieving congruence while approximating a target surface. The method is validated through numerical examples and demonstrated in a complex architectural project.
ENGINEERING STRUCTURES
(2023)
Article
Computer Science, Software Engineering
F. Zoccheddu, E. Gobbetti, M. Livesu, N. Pietroni, G. Cherchi
Summary: HexBox is an intuitive method and tool for creating and editing hexahedral meshes. It allows users to box-model a volumetric mesh by modifying its surface through various operations. It achieves efficiency by maintaining parallel data structures and utilizing recent advancements in grid-based meshing.
COMPUTER GRAPHICS FORUM
(2023)
Article
Computer Science, Software Engineering
Claudio Mancinelli, Giacomo Nazzaro, Fabio Pellacini, Enrico Puppo
Summary: We propose a practical framework for converting Bezier curves to surfaces. Our framework supports interactive drawing and editing of Bezier splines on manifold meshes with millions of triangles, using repeated manifold averages. We demonstrate that direct extensions of evaluation algorithms to the manifold setting are fragile, while subdivision-based approaches are robust and efficient. Our framework includes algorithms for curve tracing, point evaluation, and approximated point insertion, achieving correct results and superior performance compared to state-of-the-art methods.
IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
(2023)
Article
Chemistry, Analytical
Arslan Siddique, Francesco Banterle, Massimiliano Corsini, Paolo Cignoni, Daniel Sommerville, Chris Joffe
Summary: MoReLab is a user-assisted 3D reconstruction tool designed to address the limitations of existing Structure from Motion (SfM) software packages in accurately estimating 3D models from low-quality videos. By allowing users to manually add features and correspondences on multiple video frames and providing primitive shape tools, MoReLab achieves superior results in modeling industrial equipment in challenging conditions.
Article
Environmental Sciences
Kai L. Kopecky, Gaia Pavoni, Erica Nocerino, Andrew J. Brooks, Massimiliano Corsini, Fabio Menna, Jordan P. Gallagher, Alessandro Capra, Cristina Castagnetti, Paolo Rossi, Armin Gruen, Fabian Neyer, Alessandro Muntoni, Federico Ponchio, Paolo Cignoni, Matthias Troyer, Sally J. Holbrook, Russell J. Schmitt
Summary: Detecting the impacts of disturbances on organisms and community composition has traditionally been limited by the spatial extent and resolution of the data collection. However, advancements in underwater photogrammetry and AI-assisted image segmentation provide solutions to this tradeoff. This study demonstrates the use of these technologies to quantify the impact of coral bleaching on a tropical reef at both a meaningful spatial scale and high resolution.
Article
Computer Science, Information Systems
Francesco Banterle, Alessandro Artusi, Alejandro Moreo, Fabio Carrara, Paolo Cignoni
Summary: Efficiency and efficacy are desirable properties for evaluation metrics in SDR and HDR imaging, but it is challenging to satisfy both simultaneously. Existing metrics like HDR-VDP 2.2 accurately mimic the HVS but are computationally expensive, while cheaper alternatives fail to capture crucial aspects of the HVS. In this work, we propose NoR-VDPNet++, a deep learning architecture that converts full-reference metrics to no-reference metrics, reducing computation burden and successfully applied in different scenarios.
Article
Engineering, Civil
Renbing An, Jiacong Yuan, Yi Pan, Duhang Yi
Summary: Traditional timber structures built on sloped land are more susceptible to seismic damage compared to structures built on flat land. The upper portion of the structure is found to be the weak point on sloped land, with potential issues such as tenon failure and column foot sliding.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Elyas Bayat, Federica Tubino
Summary: The current design guidelines for assessing floor vibration performance do not consider the influence of variability in the walking path on the dynamic response of floors. This study investigates the dynamic response of floors under a single pedestrian walking load, taking into account the randomness of the walking path and load. The effectiveness of the current guidelines in predicting floor response is critically assessed.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Gao Ma, Chunxu Hou, Hyeon-Jong Hwang, Linghui Chen, Zhenhao Zhang
Summary: Minimizing earthquake damage and improving repair efficiency are the main principles of resilient structures. This study proposed a repairable column with UHPC segments and replaceable energy dissipaters. The test results showed that the columns with UHPC segments and replaceable dissipaters exhibited high strength, deformation capacity, and energy dissipation.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Kartheek S. M. Sonti, Pavan Kumar Penumakala, Suresh Kumar Reddy Narala, S. Vincent
Summary: In this study, the compressive behavior of alumina hollow particles reinforced aluminum matrix syntactic foams (AMSF) was investigated using analytical, numerical, and experimental methods. The results showed that the FE solver ABAQUS could accurately predict the elastic and elastio-plastic behavior of AMSFs. The study also suggested that FE models have great potential in developing new materials and composites under compression loading.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Zheqi Peng, Xin Wang, Zhishen Wu
Summary: In this study, the statistical modeling of fiber-reinforced polymer (FRP) cables using the classic fiber bundle model is explored. The study considers important features of large-scale multi-tendon FRP cables, such as initial random slack and uneven tensile deformation among tendons. A parametric study and reliability analysis are conducted to predict the load-displacement relation and design thousand-meter-scale FRP cables. The study emphasizes the relation between the reliability index beta of the cable and the safety factor gamma of the FRP material.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Yanchao Shi, Shaozeng Liu, Ye Hu, Zhong-Xian Li, Yang Ding
Summary: This paper introduces a damage assessment method for reinforced concrete (RC) columns under blast loading, using modal parameter measurement as the evaluation index. The validity of the proposed method is validated through numerical and experimental analysis. The results show that this modal-based damage assessment method is applicable for non-destructive evaluation of blast-induced damage of RC columns.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Xiaolin Zou, Maosheng Gong, Zhanxuan Zuo, Qifang Liu
Summary: This paper proposes an efficient framework for assessing the collapse capacity of structures in earthquake engineering. The framework is based on an accurate equivalent single-degree-of-freedom (ESDOF) system, calibrated by a meta-heuristic optimization method. The proposed framework has been validated through case studies, confirming its accuracy and efficiency.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Jie Hu, Weiping Wen, Chenyu Zhang, Changhai Zhai, Shunshun Pei, Zhenghui Wang
Summary: A deep learning-based rapid peak seismic response prediction model is proposed for the most common two-story and three-span subway stations. The model predicts the peak seismic responses of subway stations using a data-driven approach and limited information, achieving good predictive performance and generalization ability, and demonstrating significantly higher computational efficiency compared to numerical simulation methods.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Jin Ho Lee, Jeong-Rae Cho
Summary: A simplified model is proposed to estimate the earthquake responses of a rectangular liquid storage tank considering the fluid-structure interactions. The complex three-dimensional structural behavior of the tank is represented by a combination of fundamental modes of a rectangular-ring-shaped frame structure and a cantilever beam. The system's governing equation is derived, and earthquake responses such as deflection, hydrodynamic pressure, base shear, and overturning moment are obtained from the solution.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
W. J. Lewis, J. M. Russell, T. Q. Li
Summary: The work discusses the key features and advantages of optimal 2-pin arches shaped by statistically prevalent load and constant axial stress. It extends the design space of symmetric arches to cover asymmetric forms and provides minimum values of constant stress for form-finding of such arches made of different materials. The analysis shows that constant stress arches exhibit minimal stress response and have potential implications for sustainability and durability of future infrastructure.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Wen-ming Zhang, Han-xu Zou, Jia-qi Chang, Tian-cheng Liu
Summary: Saddle position is crucial in the construction and control of suspension bridges. This study proposes an analytical approach to estimate the saddle positions in the completed bridge state and discusses the calculation under different definitions. The relationship between the saddle position and the tower's centerline is analyzed, along with the eccentric compression of the tower. The feasibility of the proposed method is verified through a real-life suspension bridge.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Shaise K. John, Alessio Cascardi, Yashida Nadir
Summary: This study experimentally investigated the use of TRM material for reinforcing concrete columns. The results showed that increasing the number of textile layers effectively increased the axial strength. Additionally, the choice of fiber type and hybrid textile configuration also had a significant impact on strength improvement. A new design model that considers the effects of both the confining matrix and textile was proposed.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Chandrashekhar Lakavath, S. Suriya Prakash
Summary: This study experimentally investigated the shear behavior of post-tensioned UHPFRC girders, considering factors such as prestress level, fiber volume fraction, and types of steel fibers. The results showed that increasing prestress and fiber dosage could enhance the ultimate load-carrying capacity of the girders, reduce crack angle, and increase shear cracking load.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Vahid Goodarzimehr, Siamak Talatahari, Saeed Shojaee, Amir H. Gandomi
Summary: In this paper, an Improved Marine Predators Algorithm (IMPA) is proposed for size and shape optimization of truss structures subject to natural frequency constraints. The results indicate that IMPA performs better in solving these nonlinear structural optimization problems compared to other state-of-the-art algorithms.
ENGINEERING STRUCTURES
(2024)
Article
Engineering, Civil
Chun-Xu Qu, Jin-Zhao Jiang, Ting-Hua Yi, Hong-Nan Li
Summary: In this paper, a computer vision-based method is proposed to monitor the deformation and displacement of building structures by obtaining 3D coordinates of surface feature points. The method can acquire a large number of 3D coordinates in a noncontact form, improve the flexibility and density of measurement point layout, and is simple and cost-effective to operate.
ENGINEERING STRUCTURES
(2024)