Thin-Walled Structures最新文献

{"title":"A 3D shell model for static and free vibration analysis of multilayered magneto-elastic structures","authors":"S. Brischetto,&nbsp;D. Cesare","doi":"10.1016/j.tws.2024.112620","DOIUrl":"10.1016/j.tws.2024.112620","url":null,"abstract":"<div><div>In this paper, an exact 3D coupled magneto-elastic shell model for static and free vibration analysis of multilayered piezomagnetic smart structures is presented. The introduction of the mixed curvilinear orthogonal reference system (<span><math><mrow><mi>α</mi><mo>,</mo><mi>β</mi><mo>,</mo><mi>z</mi></mrow></math></span>) allows investigations of plates, cylindrical shells, cylinders and spherical shells as actuators or sensors and also in free vibration conditions. The present exact 3D coupled shell model is composed of four second-order differential equations whose primary variables are the three displacements <span><math><mi>u</mi></math></span>, <span><math><mi>v</mi></math></span> and <span><math><mi>w</mi></math></span> and the magnetic potential <span><math><mi>ψ</mi></math></span>. Displacements, stresses, strains, magnetic potential, magnetic induction and circular frequency values are computed to understand the behaviour of piezomagnetic smart structures. The resolution method adopted for the present 3D magneto-elastic problem is based on harmonic forms in <span><math><mi>α</mi></math></span> and <span><math><mi>β</mi></math></span> in-plane directions and the exponential matrix method in the <span><math><mi>z</mi></math></span> direction. Simply supported one-layered/multilayered structures with <span><math><mrow><mn>0</mn><mo>°</mo></mrow></math></span> or <span><math><mrow><mn>90</mn><mo>°</mo></mrow></math></span> orthotropic angles have been analysed. The results section is divided into a first part related to the validation of the proposed 3D model and a second part where new benchmark cases are presented and discussed. Different lamination schemes, load boundary conditions, geometries and materials are studied. Magneto-elastic coupling, thickness and material layer effects are discussed for thin and thick structures. The main novelty of the present exact 3D coupled magneto-elastic shell model stands in the ability to analyse several geometries and multilayered configurations embedding piezomagnetic materials under the action of different boundary loads via a general mathematical formulation.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112620"},"PeriodicalIF":5.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664005","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 performance prediction for corrugated steel web girders based on machine-learning algorithms","authors":"Yong Liu ,&nbsp;Wei Ji ,&nbsp;Jieqi Li ,&nbsp;ShiBo Liu ,&nbsp;Wenjuan Yang","doi":"10.1016/j.tws.2024.112668","DOIUrl":"10.1016/j.tws.2024.112668","url":null,"abstract":"<div><div>This study aimed to predict the shear strength of corrugated steel web girders (CSWGs) by developing a new method based on four machine-learning (ML) algorithms, namely the support vector machine, artificial neural network, random forest, and XGBoost. Based on the acquired experimental and numerical data, a database containing 552 samples was constructed to train and test the ML models. A five-fold cross-validation approach was adopted during training to prevent model overfitting. A RandomizedSearchCV was used to optimize the hyperparameters of each model. The performance of the trained models was evaluated using four performance metrics, and the results revealed that the coefficients of determination (R²) of all ML models exceeded 0.97 when used on both training and validation sets, demonstrating the excellent performance of the ML models in predicting the shear strength of CSWGs. Additionally, the implemented ML models outperformed existing design codes and empirical formulae. The XGBoost model yielded the best prediction results with an R² of 0.999, mean absolute error of 44.98 kN, root-mean-square error of 66.67 kN, and mean absolute percentage error of 2.1 %. By using the Shapley additive explanation to derive a visual, quantitative explanation of the XGBoost model, the yield strength, web thickness, and web height were identified as the most critical factors affecting the shear strength of CSWGs, and their average absolute Shapley values accounted for approximately 91.45 % of the total value. The ML models implemented in this study provide a promising new approach for pre-designing and verifying the stability of CSWGs.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112668"},"PeriodicalIF":5.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593911","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":"An origami-wheeled robot with variable width and enhanced sand walking versatility","authors":"Jie Liu ,&nbsp;Zufeng Pang ,&nbsp;Zhiyong Li ,&nbsp;Guilin Wen ,&nbsp;Zhoucheng Su ,&nbsp;Junfeng He ,&nbsp;Kaiyue Liu ,&nbsp;Dezheng Jiang ,&nbsp;Zenan Li ,&nbsp;Shouyan Chen ,&nbsp;Yang Tian ,&nbsp;Yi Min Xie ,&nbsp;Zhenpei Wang ,&nbsp;Zhuangjian Liu","doi":"10.1016/j.tws.2024.112645","DOIUrl":"10.1016/j.tws.2024.112645","url":null,"abstract":"<div><div>Robots inspired by origami that offer several benefits, including being lightweight, requiring less assembly, and possessing remarkable deformability, have drawn a lot of interest. However, the existing origami-inspired robots are usually of limited functionalities and developing feature-rich robots is very challenging. Here, we report an origami-wheeled robot (OriWheelBot) with exceptional mobility for sand walking and a changing width. Origami wheels created using Miura origami permit the OriWheelBot to alter wheel width over obstacles. We derive the variable-width and diameter analytical models of the origami wheel, assuming rigid-folding, which has been confirmed by testing. An enhanced variant, dubbed iOriWheelBot, is additionally being developed to autonomously determine the obstacle's breadth. Based on the width of the channel between the barriers, three actions will be executed: direct pass, variable width pass, and direct return. Sand-pushing is more suitable for walking on the sand than sand-digging, which is the other of the two motion mechanisms that we have identified. Many aspects of sand walking, including carrying loads, walking on a slope, climbing a slope, and negotiating sand pits, small rocks, and sand traps, have been methodically investigated. The OriWheelBot can climb a 17-degree sand incline, vary its width by 40 %, and have a loading-carrying ratio of 66.7 % on flat sand. Rescue operations in disaster areas and planetary subsurface exploration can benefit from the OriWheelBot.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112645"},"PeriodicalIF":5.7,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587048","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":"Oscillating laser-arc hybrid additive manufacturing of aluminum alloy thin-wall based on synchronous wire-powder feeding","authors":"Yunfei Meng,&nbsp;Qianxi Yu,&nbsp;Xu Wu,&nbsp;Xiaohan Guo,&nbsp;Ziheng Yang,&nbsp;Lidong Xu,&nbsp;Hui Chen","doi":"10.1016/j.tws.2024.112665","DOIUrl":"10.1016/j.tws.2024.112665","url":null,"abstract":"<div><div>Synchronous wire-powder feeding was adopted to overcome the poor mechanical properties of aluminum alloy thin-wall caused by limited filling composition in wire-based laser-arc hybrid additive manufacturing. The results showed that the optimized Mg powder feeding improved the droplet transfer into a fine spray mode with reduced transition time by 18 %. Moreover, not only the effective width coefficient of thin-wall increased from 89 % to 95 %, but also the subsequent machining allowance reduced from 1.25 to 0.48 mm. The synchronous wire-powder feeding improved the formation accuracy by 61.6 %. Although the deposition microstructure was mainly composed of dendrites with obvious direction and increased average grain size by 54 %, a new Mg₂Si strengthened phase was also found. The ultimate tensile strength of thin-wall was increased by 12 % from 227.3 to 255.5 MPa. The related evolution mechanisms of deposition stability and mechanical properties by optimized powder feeding on the hybrid additive manufacturing were mainly discussed.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112665"},"PeriodicalIF":5.7,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593967","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":"Research on damage repair and high-velocity impact characteristics of thermoplastic composites","authors":"Feng Jin,&nbsp;Lulu Liu,&nbsp;Xinying Zhu,&nbsp;Zhihao Xie,&nbsp;Wei Chen","doi":"10.1016/j.tws.2024.112663","DOIUrl":"10.1016/j.tws.2024.112663","url":null,"abstract":"<div><div>Low-velocity impact (LVI) can result in imperceptible damage to carbon fiber reinforced thermoplastic composites (CFRTP) laminates during service, leading to a reduction in structural strength. The thermal repair of damaged CFRTP laminates is conducted using the repairability of thermoplastic resin at high temperatures. However, the high-velocity impact characteristics of CFRTP laminates following thermal repair remain uncertain. This study examines CFRTP laminates made of two different materials (CF/PEEK and CF/PPS) with varying levels of low-velocity impact damage, and investigates the thermal repair process. A comparative experimental analysis examined the high-speed impact characteristics of CFRTP laminates under varying conditions. The results indicate that CF/PEEK laminates consistently exhibit superior compressive properties and impact resistance compared to CF/PPS laminates under similar conditions. Following damage from low-velocity impact, the compressive properties and high-velocity impact resistance of CFRTP laminates decrease, with CF/PPS laminates typically showing a lower performance retention rate. However, the thermal repair process proposed in this study significantly enhances the performance of CF/PPS laminates. Moreover, the degree of performance healing in CF/PPS laminates is consistently higher than that in CF/PEEK laminates, which is closely related to the semi-crystalline nature of PEEK resin.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112663"},"PeriodicalIF":5.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587049","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":"Statistical characteristics of realistic fiber misalignments of unidirectional composites: Fitting distributions and scanning length effects","authors":"Tao Zheng ,&nbsp;Fenghao Jia ,&nbsp;Zhongyu Wang ,&nbsp;Zhanguang Chen ,&nbsp;Fengnan Guo ,&nbsp;Licheng Guo","doi":"10.1016/j.tws.2024.112621","DOIUrl":"10.1016/j.tws.2024.112621","url":null,"abstract":"<div><div>This paper presents a comprehensive study on the statistical characteristics of angle, tortuosity, curvature and wave magnitude to deepen the understanding of realistic fiber misalignments within unidirectional composites. A feasible fiber path reconstruction procedure has been optimized, which can be applicable to other types of composites. The high-resolution micrographs are acquired through X-ray computed tomography. The individual fiber segmentation is implemented using a U-Net deep learning method, and the fiber trajectories are reconstructed with the aid of a tracing algorithm. The stepped fiber trajectories are slightly smoothed and a polynomial fitting formula is adopted to quantitatively describe the fiber paths. The statistical characteristics corresponding to the differential tortuosity, misalignment angle, spatial curvature and wave magnitudes are comprehensively analyzed, with emphasis on their fitting distributions and scanning length effects. The collected data indicate that the statistical distributions of differential tortuosity and angle, curvature, and wave magnitude can be well fitted by normal, lognormal and Weibull equations, respectively. Particularly, the differential tortuosity and wave magnitude are overall features of individual fiber trajectory, which are highly correlated with the scanning length. In contrast, the angle and curvature are local features, so a smaller scanning length could obtain convergent results.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112621"},"PeriodicalIF":5.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661810","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":"Mechanical performance analysis method for ribbed H-section aluminum alloy members with initial curvature and torsion angle","authors":"Guojun Sun ,&nbsp;Bo Li ,&nbsp;Jinzhi Wu","doi":"10.1016/j.tws.2024.112662","DOIUrl":"10.1016/j.tws.2024.112662","url":null,"abstract":"<div><div>In this study, an experimental investigation was conducted on the axial compression performance of ribbed H-section aluminum alloy members with initial curvature and torsion angle under varying boundary conditions, including one end hinged with the other rigidly connected, and both ends rigidly connected. Ultimate bearing capacity and failure modes were identified under real loads and subsequently compared with previous findings from our research group on members with hinged ends. To account for initial imperfections introduced during processing and transportation, 3D scanning technology was utilized to capture the precise geometrical dimensions, constructing an accurate numerical simulation model. The experimental results were corroborated with numerical simulations, leading to the proposal of an analytical method for members with initial curvature and torsion angle. Furthermore, extensive parametric analysis elucidated the impact of initial curvature, torsion angle, and slenderness ratio on the ultimate bearing capacity, culminating in the formulation of the stability factor and calculated length factor based on numerical outcomes. The study discovered significant variances in bearing capacity under different boundary conditions, with one-end hinged and one-section rigidly connected, and two-end rigidly connected conditions exhibiting 1.4 and 2.1 times the capacity of the hinged-at-both-ends scenario. Under different boundary conditions, the axial compression members were subjected to flexural-torsional buckling failure. Moreover, when the ultimate bearing capacity was reached, the lower flange of the member and the web near the lower flange appeared obvious buckling phenomenon. The numerical analysis aligned well with experimental data, validating the simulation method's reliability and revealing the stress distribution and evolution during member failure. These findings offer vital theoretical insights and technical support for engineering design and practical applications.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112662"},"PeriodicalIF":5.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663887","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 elastic buckling of corrugated steel plate shear walls with stiffeners considering torsional rigidity","authors":"Ruo-Min Wu,&nbsp;Chao-Qun Yu,&nbsp;Ling-Qi Wang,&nbsp;Jing-Zhong Tong","doi":"10.1016/j.tws.2024.112646","DOIUrl":"10.1016/j.tws.2024.112646","url":null,"abstract":"<div><div>This paper conducted theoretical and numerical investigations on shear elastic buckling formulas of stiffened corrugated steel plate shear walls (SCSPSWs) considering torsional rigidities of stiffeners. Firstly, based on the orthotropic plate theory and the energy method, a theoretical model for the derivation of elastic buckling coefficients was established, introducing the torsional strain energy term of the stiffeners. On this basis, the variation law of the elastic buckling coefficient of the walls concerning the stiffener positions was studied, determining the optimal layout of the stiffeners. The formula for calculating the elastic buckling coefficient at any stiffener layout was provided. Furthermore, based on the stiffeners arranged in the optimal layout, the transition torsional rigidity of the stiffeners was determined, and the formulas for the elastic buckling coefficient of the SCSPSW with stiffeners considering torsional rigidity were proposed, in which the enhancement of torsional constraints provided by the stiffeners was measured by an enhancement factor. Finally, eigenvalue buckling analyses were performed based on finite element models to validate the theoretical analysis results on the optimal stiffener layout and elastic buckling coefficient.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112646"},"PeriodicalIF":5.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587051","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":"Bending behaviors of 3D printed sandwich structures with functionally graded porous lattice cores","authors":"Meiling Fan ,&nbsp;Tao Zeng ,&nbsp;Rina Wu ,&nbsp;Yuhua Cui ,&nbsp;Guodong Xu ,&nbsp;Xiaohong Wang ,&nbsp;Su Cheng ,&nbsp;Jue Zhao","doi":"10.1016/j.tws.2024.112655","DOIUrl":"10.1016/j.tws.2024.112655","url":null,"abstract":"<div><div>A novel graded porous lattice core sandwich structure is presented to achieve a balance between lightweight and high mechanical performance for materials. An analytical model is proposed to investigate the bending responses of graded porous lattice core sandwich structures by utilizing the homogenization and dehomogenization method. A comprehensive parametric investigation on the mechanical behaviors of the graded lattice sandwich structures is conducted in order to design and optimize these materials. The precise control of porosity is implemented utilizing 3D printing techniques in this study. The theoretical results are validated by the experiments using 3D printed samples. It is found that mechanical properties can be improved through optimization of pore gradient distribution in the lattice core while maintaining a light weight of the sandwich structures. These findings offer valuable insights for designing tailored sandwich structures that are suitable for a diverse range of engineering applications.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112655"},"PeriodicalIF":5.7,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663924","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":"Numerical study on the effects of alloying variations on the crushing behaviour of an aluminium profile","authors":"Marcos Fernandez,&nbsp;Miguel Costas,&nbsp;Odd Sture Hopperstad,&nbsp;David Morin","doi":"10.1016/j.tws.2024.112618","DOIUrl":"10.1016/j.tws.2024.112618","url":null,"abstract":"<div><div>The effects of variations in the chemical composition of an aluminium alloy AA6005 on the axial crushing and bending behaviour of a double chamber extruded profile are investigated by shell-based finite element analyses. A novel sequential modelling method, including nanostructure modelling, virtual tensile testing and localisation analyses, is used to determine the yield strength, work-hardening, and ductility of several variants of the AA6005 alloy. The data obtained from the models are used to calibrate the parameters of an isotropic elastic–plastic constitutive model and an uncoupled damage criterion. Explicit finite element analyses of axial crushing and three-point bending of the double chamber extruded profile are conducted for all variants of the AA6005 alloy in temper T6. By comparing the results of the finite element analyses with existing experimental data, the results reveal how variations in the chemical composition significantly influence the structural integrity of the extruded aluminium profile in axial crushing and bending.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"206 ","pages":"Article 112618"},"PeriodicalIF":5.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}