Honggang Li , Tiancai Tan , Xiaoguang Guo , Renke Kang , Dongqi An , Shang Gao
{"title":"Analytical solution for gravity-induced deflection of open cylindrical thin-shell under three-point support","authors":"Honggang Li , Tiancai Tan , Xiaoguang Guo , Renke Kang , Dongqi An , Shang Gao","doi":"10.1016/j.tws.2025.114035","DOIUrl":"10.1016/j.tws.2025.114035","url":null,"abstract":"<div><div>Thin-shell mirrors are essential elements in nested X-ray focusing optics. Due to their thin-walled structure, these mirrors are sensitive to gravity-induced deflection during surface shape metrology. This inevitable deflection resulted in optical surface evaluation deviation, leading to significant measurement inaccuracies. To address this issue, this study innovatively proposes a three-point support strategy combined with computational compensation to mitigate the gravity effects. An analytical mechanical model was developed to predict gravity-induced deflection in open cylindrical thin-shells under three-point support. Using the double finite Fourier integral transform method, the exact closed-form solutions for the governing deflection functions were derived, providing a model applicable to random shell geometries, material properties, and support parameters. The analytical model was validated through finite element simulations and analytical calculations comparisons, showing excellent agreement with errors below 3%. Experimental measurements on the polished thin-shell mirrors confirmed the effectiveness of model in recovering the surface true shape profile by subtracting predicted deflections from measured profiles. It was also found that symmetrical support locations promote favorable load distribution and reduce thin-shell deformation. The proposed analytical model provides an efficient and general computational method for gravity compensation under three-point support, enabling high-accuracy surface shape metrology of open cylindrical thin-shell structures.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114035"},"PeriodicalIF":6.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiahao Lin , Heran Wang , Shuchang Long , Xiaoqing Zhang , Xiaohu Yao
{"title":"Mechanisms of crack initiation and evolution in quasi-isotropic composite laminates under low-velocity impact","authors":"Jiahao Lin , Heran Wang , Shuchang Long , Xiaoqing Zhang , Xiaohu Yao","doi":"10.1016/j.tws.2025.114029","DOIUrl":"10.1016/j.tws.2025.114029","url":null,"abstract":"<div><div>Quasi-isotropic composite laminates are widely used in engineering due to their excellent mechanical properties and design flexibility. However, under low-velocity impact, internal intra-laminar cracks and delamination can occur, leading to significant internal damage that may compromise structural integrity. This study focuses on the mechanisms of crack and delamination initiation, propagation, and interaction in quasi-isotropic composite laminates under low-velocity impact using XFEM. CT scans after low-velocity impact were conducted to capture crack characteristics. The results reveal the mechanisms of the initiation and propagation of intra-laminar cracks, and uncover that the presence of intra-laminar cracks triggers delamination initiation due to stress amplification at crack tip. Additionally, the study highlights the influence of ply angles on structural damage resistance, providing insights into the optimal layup design to enhance impact resistance. These findings contribute to a deeper understanding of damage evolution in quasi-isotropic composite laminates, offering valuable guidance for the structural optimization of impact-resistant materials.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114029"},"PeriodicalIF":6.6,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Zhang , Changlong Shi , Xiaohui Zhang , Jian Feng , Jianguo Cai
{"title":"Interleaved assembly and compressive behavior of non-Euclidean origami structures","authors":"Qian Zhang , Changlong Shi , Xiaohui Zhang , Jian Feng , Jianguo Cai","doi":"10.1016/j.tws.2025.113994","DOIUrl":"10.1016/j.tws.2025.113994","url":null,"abstract":"<div><div>The motion paths of non-Euclidean origami units are more easily controllable than those of Euclidean origami units, effectively suppressing bifurcation singularities. This study first introduces an origami tube constructed from two types of non-Euclidean units, preserving the characteristics of single-degree-of-freedom motion and flat-foldability, while exhibiting distinct motion properties compared to traditional origami tubes, enabling a switch between two folding states within the same plane. Leveraging geometric compatibility conditions, the non-Euclidean origami tube can be interleaved to form a staggered basic origami unit cell. The geometric characteristics in three directions, including the range of rigid movements and self-locking conditions, are analyzed in detail. Additionally, by mirroring the basic unit cell and arranging them into an array, an interleaved origami metamaterial is created that offers a more convenient assembly method than conventional interleaved origami tubes, demonstrating unique motion patterns in all three directions. Using the Z-direction compression process as a case study, the research employs theoretical analysis, simulation, and experimental methods to reveal a distinct two-stage gradient characteristic during compression. The first stage is characterized by a rigid motion process dominated by crease rotation, while the second stage exhibits a diamond honeycomb compression mode represented by panel deformation. The findings of this study provide a novel design paradigm for interleaved origami tubes, presenting significant potential for developing mechanically metamaterials with enhanced motion and mechanical properties.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 113994"},"PeriodicalIF":6.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Shear behaviour of a novel self-locking inter-module connection with spring-loaded plunger latches","authors":"Jiahao Peng, Chao Hou, Xinxiang Liang","doi":"10.1016/j.tws.2025.114034","DOIUrl":"10.1016/j.tws.2025.114034","url":null,"abstract":"<div><div>One of the greatest challenges in designing modular buildings lies in the inter-module connection, which is distinct from conventional structural systems. The role it plays is essential not only in determining the structural responses of stacked modules but also in enhancing the efficiency of on-site assembly. Among many existing designs, the proposed self-locking inter-module connection emerges as a promising solution, offering a balanced integration of functionality and workability. This study aims to explore the structural behaviour of the self-locking connection under shear through both experimental and numerical approaches, and to contribute valuable insights into the safe design of multi-storey modular buildings subject to lateral loads that may be generated from winds, seismics, and localised damages. First, a total of six full-scale specimens with various sleeve configurations were tested in a double-shear arrangement to identify the typical failure mode, which was found to be the fracture of protruded sleeve for all the tested specimens. By calibrating the ductile fracture simulation, a finite element model was established and proven reliable in predicting the structural responses of the connection under shear. This model was then used to evaluate the full-range damage evolution of critical components, as well as serving as an effective means to explore the effects of parameters. Finally, a simplified calculation method was developed by examining the relationship between the effective area for shear and the aspect ratio of the sleeve section, offering a practical solution for routine engineering designs.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114034"},"PeriodicalIF":6.6,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanfang Ma , Sihao Han , Chunlei Li , Buyun Su , Xin Li , Qiang Han , Xiaohu Yao
{"title":"Impact behavior and energy absorption improvement mechanism of vertex-based hierarchical origami honeycomb","authors":"Nanfang Ma , Sihao Han , Chunlei Li , Buyun Su , Xin Li , Qiang Han , Xiaohu Yao","doi":"10.1016/j.tws.2025.114030","DOIUrl":"10.1016/j.tws.2025.114030","url":null,"abstract":"<div><div>Origami-inspired honeycomb structures have garnered significant research interest in recent years. The re-entrant origami honeycomb (ROH) is proposed by combining the Miura origami and re-entrant honeycomb. The incorporation of origami units can significantly enhance the in-plane mechanical properties of the re-entrant honeycomb but reduces its out-of-plane load-bearing capacity. In this paper, the vertex-based hierarchical design is applied to the conventional ROH to improve the out-of-plane mechanical performance of the structure. The crashworthiness of the conventional ROH and the novel hierarchical re-entrant origami honeycomb (VHROH) is systematically investigated by experimental testing, theoretical analysis and numerical simulation. The results indicate that VHROH structure exhibits significantly enhanced impact resistance and energy absorption in both in-plane and out-of-plane directions compared with ROH structure. An in-depth analysis of the deformation patterns and energy absorption mechanisms elucidates the underlying reasons for the enhanced performance of the VHROH structure. Parametric analysis demonstrated that adjustments to substructure size and folding dihedral angle can effectively regulate the structure’s crashworthiness in both in-plane and out-of-plane directions. In addition, the negative Poisson’s ratio effect of the VHROH structure is diminished compared with that of the ROH structure in both in-plane and out-of-plane directions.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114030"},"PeriodicalIF":6.6,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Failure mechanism and shear strength of Fe-SMA-to-steel dissimilar bonded joints under aging conditions","authors":"Yue Shu, Xu Jiang, Xuhong Qiang, Wulong Chen","doi":"10.1016/j.tws.2025.114032","DOIUrl":"10.1016/j.tws.2025.114032","url":null,"abstract":"<div><div>Owing to their shape memory effect and ability to achieve uniform stress distribution, bonded iron-based shape memory alloy (Fe-SMA) patches have emerged as a promising solution for strengthening aging steel structures, offering significant improvements in mechanical performance. However, the durability of Fe-SMA-to-steel dissimilar bonded joints (DBJs) remains insufficiently understood, limiting the wider application of bonded Fe-SMA patches in structural reinforcements. This study establishes and validates numerical models of Fe-SMA-to-steel DBJs based on experimental results from 108 specimens. The validated model is employed to analyze the progressive damage of DBJs under various parameters, including bond length, adhesive type, adhesive thickness, Fe-SMA thickness, and aging condition. The numerical results show good agreement with experimental results, with maximum and average prediction errors of 14 % and 3 % on the ultimate shear load, respectively. The numerical analysis reveals that the transfer of shear stress is governed by an effective bond region, and the Boltzmann predicting model is proposed to determine the effective bond length. This length increases with the exposure time, reaching a maximum improvement of 74 %. The ultimate shear load of DBJs linearly improves with the square root of Fe-SMA thickness, unaffected by aging conditions and adhesive types. Nevertheless, the ultimate shear load declines with the prolonged exposure time. These research findings offer valuable design guidelines for adhesively Fe-SMA-reinforced infrastructures, guaranteeing the reliability and durability of the parent structures in practical scenarios and contributing to reducing the carbon emissions of infrastructures.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114032"},"PeriodicalIF":6.6,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic stiffness–based free vibration study of moderately thick circular cylindrical shells","authors":"Nevenka Kolarević, Marija Nefovska-Danilović","doi":"10.1016/j.tws.2025.114020","DOIUrl":"10.1016/j.tws.2025.114020","url":null,"abstract":"<div><div>This paper presents an advanced application of the dynamic stiffness method for the free vibration analysis of moderately thick circular cylindrical shells, based on a generalized Flügge shell theory accounting for shear deformation, rotary inertia and effects of initial stresses. Unlike previous studies, the governing differential equations are solved exactly for each frequency of interest, eliminating the need for numerical approximations in the solution process. An exact dynamic stiffness matrix derived from the strong-form solution is developed for a fully free cylindrical shell element and implemented in a genuine MATLAB code to efficiently compute natural frequencies and mode shapes. The numerical study includes examples featuring stepwise thickness variations, intermediate supports, and initial stresses, providing insights into a wide range of structural applications. The results are validated through comparison with finite element analysis and published data, demonstrating the accuracy, reliability, and computational efficiency of the proposed approach for complex cylindrical shell structures. Additionally, the proposed method addresses limitations of previous studies by capturing all relevant natural frequencies. Finally, numerous high-accuracy results are provided to serve as benchmark solutions for validating future research in this field.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114020"},"PeriodicalIF":6.6,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhong-yu Zhang , Prasad Mattipally , Syed Waheedullah Ghori , Abdullah Alzlfawi , Mohammed Javeed Siddique , Mohammed Al-Bahrani , Rajeshkumar Selvaraj
{"title":"Vibration damping and instability analysis of glass/carbon fiber reinforced sandwich plates with 3D printed honeycomb core under rotating condition","authors":"Zhong-yu Zhang , Prasad Mattipally , Syed Waheedullah Ghori , Abdullah Alzlfawi , Mohammed Javeed Siddique , Mohammed Al-Bahrani , Rajeshkumar Selvaraj","doi":"10.1016/j.tws.2025.114019","DOIUrl":"10.1016/j.tws.2025.114019","url":null,"abstract":"<div><div>In this work, the damping, vibration, and instability characteristics of the rotating sandwich plate with a 3D-printed honeycomb core and glass/carbon fiber-reinforced composite skins are analyzed. The laminated composites are created using the vacuum-assisted hand layup method, and honeycomb cores are fabricated using a 3D printer. An experimental investigation was done to examine the vibrations of 3D-printed honeycomb sandwich composites. A finite element method-based higher-order shear deformation theory (HSDT) is used to obtain the governing equations for the sandwich plate. Further, a thorough parametric study is conducted to examine the effect of rotational speed, aspect ratio, core thickness, hub radius and setting angle on the vibration, damping, and instability characteristics of the glass/carbon fiber composite sandwich plate with a 3D-printed honeycomb core. From the obtained results, it can be concluded that the skin layer's hybrid fiber reinforcement greatly influences the vibration, damping, and instability characteristics of the rotating 3D-printed honeycomb sandwich plates.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114019"},"PeriodicalIF":6.6,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Songjing Liu , Yanwei Ding , Yu Feng , Wenqian Wang , Chunwang Niu , Jialu Wang
{"title":"Low-velocity impact size effect of carbon fiber composite laminates: Experimental and mechanism research","authors":"Songjing Liu , Yanwei Ding , Yu Feng , Wenqian Wang , Chunwang Niu , Jialu Wang","doi":"10.1016/j.tws.2025.114028","DOIUrl":"10.1016/j.tws.2025.114028","url":null,"abstract":"<div><div>The low-velocity impact (LVI) response characteristics of carbon fiber composite laminates under the influence of the size effect was investigated. Firstly, LVI experiments were conducted on composite laminates with varying in-plane dimensions and thicknesses under different impact energies to analyze their LVI response patterns. Secondly, non-destructive testing methods were utilized to examine the surface and internal damage conditions of the laminates, elucidating the LVI damage response characteristics influenced by the size effect. Finally, high-speed imaging and scanning electron microscopy (SEM) techniques were employed in conjunction to reveal the underlying mechanisms of the size effect during LVI on composite laminates. The findings indicate that under identical impact energy conditions, as the in-plane dimension of the laminate increases (with constant thickness), the peak force and absorbed energy progressively decrease, while the maximum displacement increases. Additionally, the degree of surface damage diminishes, and the projected area of internal damage reduces and becomes more concentrated near the impact surface in the depth direction. As the thickness of the laminate increases (with constant in-plane dimension), the peak force and the slope K value of the Displacement-Time curve increase, whereas the absorbed energy initially decreases and then slightly rises, the maximum displacement decreases, the degree of surface damage weakens, and the projected area of internal damage expands. An increase in the in-plane dimension of the laminate facilitates the absorption and dissipation of impact energy through elastic deformation, thereby reducing the extent of internal damage. Meanwhile, an increase in laminate thickness enhances the likelihood of matrix damage and delamination damage propagation. The initiation and propagation of damage across multiple layers of the matrix absorb a significant portion of the impact energy, consequently mitigating fiber fracture damage.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114028"},"PeriodicalIF":6.6,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Finite element buckling analysis for micro structures based on the couple stress theory","authors":"Yang Bae Jeon , Gi-Dong Sim , Jae-Hoon Choi","doi":"10.1016/j.tws.2025.114023","DOIUrl":"10.1016/j.tws.2025.114023","url":null,"abstract":"<div><div>Mechanical behavior at the micro- and nano-scale exhibits size-dependent effects, such as increased stiffness, which are not captured by classical continuum mechanics. These effects become particularly important in thin structures, where buckling is a critical failure mode; however, previous studies have been limited to simple geometries due to the complexity of the governing equations. This study develops a finite element framework for buckling analysis based on the modified couple stress theory (MCST), applicable to arbitrary geometries. Beam and shell elements are formulated to incorporate size effects, enabling buckling analysis of general structures. The framework is demonstrated on various configurations, including thin membranes under residual stress, stiffened plates, and tensile bars, highlighting its versatility. Numerical results show that accounting for size effects consistently increases the predicted critical buckling loads compared to classical continuum mechanics. The proposed approach offers a broadly applicable tool for stability assessment in micro-electromechanical systems (MEMS), flexible electronics, and thin-film micro sensors and actuators.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"218 ","pages":"Article 114023"},"PeriodicalIF":6.6,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}