Thin-Walled Structures最新文献_第9页

Experimental analysis and a new model to predict web-post buckling of corroded Anglo-Saxon castellated beams 腐蚀盎格鲁-撒克逊城堡梁腹板后屈曲的试验分析及新模型

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114417

André Vitor Benedito , Pablo Augusto Krahl , Vinicius Brother dos Santos , Vinicius Moura de Oliveira , Alexandre Rossi , Flávio de Andrade Silva , Daniel Carlos Taissum Cardoso , Carlos Humberto Martins

Castellated beams, recognized for their favorable strength-to-weight ratio and ease of utility passage, are widely used. Despite extensive studies focusing on their flexural performance, a significant research gap remains regarding the effects of corrosion, particularly in terms of web-post buckling (WPB). There are no experiments reported or formulations to predict the buckling of corroded webs. To address this gap, four full-scale beams, comprising two corroded and two non-corroded specimens of ASTM A572 Grade 50 and Grade 60 steels, were tested under three-point bending. The influence of corrosion on buckling was assessed using digital image correlation (DIC) in conjunction with pit morphology analysis and mass loss measurements. Additionally, a new rational formulation was proposed incorporating periodic thickness variation to account for corrosion pits. Experimental results indicated substantial reductions in load-bearing capacity due to corrosion, approximately 39 % for Grade 50 and 36 % for Grade 60. The analytical model demonstrated high accuracy for the present tests, with mean deviations of about 8.5 % and 2.9 % for the non-corroded Grade 50 and Grade 60 beams and about 1.7 % for the corroded specimens. When applied to additional non-corroded beams from the literature, the model showed mean deviations of about 7 %. For the non-corroded case, existing design provisions produced less accurate predictions: EN 1993–1–13:2024 underestimated the experimental results by an average of 40.8 %, whereas Steel Design Guide 31 overestimated the critical shear load by an average of 17.4%. The findings underscore the importance of considering corrosion-induced slenderness to predict structural stability and durability of castellated beams.

城堡梁以其良好的强度重量比和易于通行而被广泛使用。尽管对其抗弯性能进行了广泛的研究，但关于腐蚀的影响，特别是在网柱屈曲（WPB）方面的研究仍然存在很大的空白。目前还没有实验报告或公式来预测腐蚀腹板的屈曲。为了解决这一差距，四个全尺寸梁，包括两个腐蚀和两个未腐蚀的ASTM A572 50级和60级钢试样，在三点弯曲下进行了测试。腐蚀对屈曲的影响采用数字图像相关（DIC）结合坑形态分析和质量损失测量来评估。此外，还提出了考虑腐蚀坑的周期性厚度变化的合理计算公式。实验结果表明，由于腐蚀，承载能力大幅下降，50级约为39%，60级约为36%。分析模型在目前的试验中显示出很高的准确性，对于未腐蚀的50级和60级梁，平均偏差约为8.5%和2.9%，对于腐蚀试件，平均偏差约为1.7%。当应用于文献中额外的未腐蚀梁时，模型显示平均偏差约为7%。对于非腐蚀情况，现有设计规定产生的预测不太准确：EN 1993 - 1 - 13:24平均低估了40.8%的实验结果，而钢设计指南31平均高估了17.4%的临界剪切载荷。研究结果强调了考虑腐蚀引起的长细对预测城堡梁结构稳定性和耐久性的重要性。

{"title":"Experimental analysis and a new model to predict web-post buckling of corroded Anglo-Saxon castellated beams","authors":"André Vitor Benedito , Pablo Augusto Krahl , Vinicius Brother dos Santos , Vinicius Moura de Oliveira , Alexandre Rossi , Flávio de Andrade Silva , Daniel Carlos Taissum Cardoso , Carlos Humberto Martins","doi":"10.1016/j.tws.2025.114417","DOIUrl":"10.1016/j.tws.2025.114417","url":null,"abstract":"<div><div>Castellated beams, recognized for their favorable strength-to-weight ratio and ease of utility passage, are widely used. Despite extensive studies focusing on their flexural performance, a significant research gap remains regarding the effects of corrosion, particularly in terms of web-post buckling (WPB). There are no experiments reported or formulations to predict the buckling of corroded webs. To address this gap, four full-scale beams, comprising two corroded and two non-corroded specimens of ASTM A572 Grade 50 and Grade 60 steels, were tested under three-point bending. The influence of corrosion on buckling was assessed using digital image correlation (DIC) in conjunction with pit morphology analysis and mass loss measurements. Additionally, a new rational formulation was proposed incorporating periodic thickness variation to account for corrosion pits. Experimental results indicated substantial reductions in load-bearing capacity due to corrosion, approximately 39 % for Grade 50 and 36 % for Grade 60. The analytical model demonstrated high accuracy for the present tests, with mean deviations of about 8.5 % and 2.9 % for the non-corroded Grade 50 and Grade 60 beams and about 1.7 % for the corroded specimens. When applied to additional non-corroded beams from the literature, the model showed mean deviations of about 7 %. For the non-corroded case, existing design provisions produced less accurate predictions: EN 1993–1–13:2024 underestimated the experimental results by an average of 40.8 %, whereas Steel Design Guide 31 overestimated the critical shear load by an average of 17.4%. The findings underscore the importance of considering corrosion-induced slenderness to predict structural stability and durability of castellated beams.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114417"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842769","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}

引用次数: 0

Enhanced in-plane mechanical performance of a novel circular honeycomb with bionic layer-by-layer orthogonal arrangement 仿生逐层正交布置的新型圆形蜂窝的面内力学性能增强

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114416

Zhigang Xu , Ziyi Li , Enpeng Guo , Diao Yang , Chuanbin Wang

This study proposed a novel layer-by-layer orthogonally arranged circular honeycomb (LOACH), inspired by the bouligand structure, to enhance energy absorption performance and lateral constraint ability of conventional circular honeycombs (CH) under in-plane compression. Experimental and finite element analyses reveal that the bionic orthogonal arrangement pattern leads to a localized symmetric depression at the vertically intersecting interface of adjacent layers of circular tubes, which makes the tubes embedded in each other and forms an interlocking structure. This interlocking structure enhances the lateral constraint of the circular honeycomb and suppresses the generation of X-deformation bands, resulting in more uniform and stable deformation. Furthermore, the localized depression mentioned above increases the plastic deformation region of individual circular tubes, enhancing LOACH’s energy absorption capacity. The specific energy absorption (SEA) of LOACH improved by 99.3% compared to CH, reaching 8.67 J/g. On the other hand, the appropriate wall thickness is the key to obtaining LOACH with high energy absorption, which is shown by the results that the maximum SEA of 10.12 J/g is obtained at a wall thickness of 0.30 mm. These findings demonstrate LOACH’s superior energy absorption and lateral constraint capabilities, offering valuable guidance for designing advanced energy-absorbing honeycomb structures.

为了提高传统圆形蜂窝在面内压缩条件下的吸能性能和侧向约束能力，研究了一种受砾石结构启发、分层正交排列的新型圆形蜂窝结构。实验和有限元分析表明，仿生正交排列模式在相邻层圆管的垂直相交界面处形成局部对称凹陷，使圆管相互嵌套，形成互锁结构。这种互锁结构增强了圆形蜂窝的侧向约束，抑制了x -变形带的产生，使变形更加均匀稳定。此外，上述局部凹陷增加了单个圆管的塑性变形区域，增强了LOACH的吸能能力。泥鳅的比能吸收（SEA）达到8.67 J/g，比CH提高了99.3%。另一方面，适当的壁厚是获得高能量吸收的关键，结果表明，当壁厚为0.30 mm时，获得的最大SEA为10.12 J/g。这些发现证明了LOACH优越的吸能和侧向约束能力，为设计先进的吸能蜂窝结构提供了有价值的指导。

{"title":"Enhanced in-plane mechanical performance of a novel circular honeycomb with bionic layer-by-layer orthogonal arrangement","authors":"Zhigang Xu , Ziyi Li , Enpeng Guo , Diao Yang , Chuanbin Wang","doi":"10.1016/j.tws.2025.114416","DOIUrl":"10.1016/j.tws.2025.114416","url":null,"abstract":"<div><div>This study proposed a novel layer-by-layer orthogonally arranged circular honeycomb (LOACH), inspired by the bouligand structure, to enhance energy absorption performance and lateral constraint ability of conventional circular honeycombs (CH) under in-plane compression. Experimental and finite element analyses reveal that the bionic orthogonal arrangement pattern leads to a localized symmetric depression at the vertically intersecting interface of adjacent layers of circular tubes, which makes the tubes embedded in each other and forms an interlocking structure. This interlocking structure enhances the lateral constraint of the circular honeycomb and suppresses the generation of X-deformation bands, resulting in more uniform and stable deformation. Furthermore, the localized depression mentioned above increases the plastic deformation region of individual circular tubes, enhancing LOACH’s energy absorption capacity. The specific energy absorption (SEA) of LOACH improved by 99.3% compared to CH, reaching 8.67 J/g. On the other hand, the appropriate wall thickness is the key to obtaining LOACH with high energy absorption, which is shown by the results that the maximum SEA of 10.12 J/g is obtained at a wall thickness of 0.30 mm. These findings demonstrate LOACH’s superior energy absorption and lateral constraint capabilities, offering valuable guidance for designing advanced energy-absorbing honeycomb structures.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114416"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842275","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}

引用次数: 0

Radiative energy transfer model and dynamic stress estimation based on Levinson beam theory 基于Levinson梁理论的辐射能量传递模型及动应力估计

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114423

Bochuan Yao , Chenghao Dai , Wenjie Zhang , Hongjun Zhang , Kunwei Liu , Haibo Chen

A novel energy flow model is developed by integrating Levinson beam theory (LBT) with the radiative energy transfer method (RETM) for high-frequency dynamic stress estimation in beam structures. A stress reconstruction procedure that explicitly resolves the transverse shear stress distribution through the cubic axial displacement function of LBT is proposed. The LBT-RETM model inherently satisfies stress-free boundary conditions and therefore eliminates non-physical stress concentrations in the traditional Timoshenko beam theory (TBT)-based model. This model is validated against the wave propagation approach. Comparative analysis with the TBT-RETM model demonstrates the superior fidelity of the LBT-RETM model, with von Mises stress distributions aligning closely with the finite element method benchmarks. The proposed LBT-RETM model achieves a Pearson’s correlation coefficient of 0.990, an average relative error of 12.13%, a peak stress error of 2.09% and outperforms the TBT-RETM model with corresponding values of 0.975, 29.80%, and 21.79%, respectively. The findings conclusively establish LBT’s advantage in high-frequency vibration stress analysis and provides critical insights into the safety design of aerospace components under extreme dynamic loads.

将Levinson梁理论（LBT）与辐射能量传递法（RETM）相结合，建立了一种用于梁结构高频动应力估计的能量流模型。提出了一种通过三次轴向位移函数明确求解横向剪应力分布的应力重建方法。LBT-RETM模型固有地满足无应力边界条件，因此消除了传统的基于Timoshenko梁理论（TBT）模型中的非物理应力集中。该模型与波传播方法进行了验证。与TBT-RETM模型的对比分析表明，LBT-RETM模型具有较好的保真度，von Mises应力分布与有限元基准非常接近。LBT-RETM模型的Pearson相关系数为0.990，平均相对误差为12.13%，峰值应力误差为2.09%，优于TBT-RETM模型的相应值分别为0.975、29.80%和21.79%。研究结果最终确立了LBT在高频振动应力分析中的优势，并为极端动态载荷下航空航天部件的安全设计提供了重要见解。

{"title":"Radiative energy transfer model and dynamic stress estimation based on Levinson beam theory","authors":"Bochuan Yao , Chenghao Dai , Wenjie Zhang , Hongjun Zhang , Kunwei Liu , Haibo Chen","doi":"10.1016/j.tws.2025.114423","DOIUrl":"10.1016/j.tws.2025.114423","url":null,"abstract":"<div><div>A novel energy flow model is developed by integrating Levinson beam theory (LBT) with the radiative energy transfer method (RETM) for high-frequency dynamic stress estimation in beam structures. A stress reconstruction procedure that explicitly resolves the transverse shear stress distribution through the cubic axial displacement function of LBT is proposed. The LBT-RETM model inherently satisfies stress-free boundary conditions and therefore eliminates non-physical stress concentrations in the traditional Timoshenko beam theory (TBT)-based model. This model is validated against the wave propagation approach. Comparative analysis with the TBT-RETM model demonstrates the superior fidelity of the LBT-RETM model, with von Mises stress distributions aligning closely with the finite element method benchmarks. The proposed LBT-RETM model achieves a Pearson’s correlation coefficient of 0.990, an average relative error of 12.13%, a peak stress error of 2.09% and outperforms the TBT-RETM model with corresponding values of 0.975, 29.80%, and 21.79%, respectively. The findings conclusively establish LBT’s advantage in high-frequency vibration stress analysis and provides critical insights into the safety design of aerospace components under extreme dynamic loads.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"220 ","pages":"Article 114423"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791288","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}

引用次数: 0

Vibration and acoustic response characteristics of re-entrant auxetic core quadrilateral sandwich panel with multi-phase composites facing under supersonic flow 超声速流动下多相复合材料复入型消声芯四边形夹层板的振动与声响应特性

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114419

Vinay Kumar Prajapati , Jeyaraj Pitchaimani , Lenin Babu Mailan Chinnapandi

Vibro-acoustics response and sound transmission loss (STL) characteristics of quadrilateral auxetic core sandwich panel (ACSP) having three-phase polymer/graphene nanoplatelets (GNP)/bio-inspired fiber (TP-PGF) composite facings under the influence of aerodynamic pressure is presented. Panel is modeled as layered structure and Hamilton’s principle is utilized to develop the governing equations. The solution is obtained using differential quadrature method (DQM) and acoustic response is analyzed using Rayleigh integral. The effects of various parameters, including bio-inspired layup scheme, mass fraction of GNP and fiber, GNP-distribution pattern, different fibers (Glass, Carbon and Kevlar), Poisson’s ratio of core (negative, zero, and positive) and facing material (isotropic and TP-PGF bio-inspired composite) are studied. Critical aerodynamic pressure (CAP) of sandwich panel is significantly influenced by the nature of bio-inspired layup scheme, mass fraction of GNP and fiber, fibers, GNP-distribution pattern of facings and core’s Poisson’s ratio. Panel with core having NPR provides the higher value of CAP. The acoustic responses such as sound power level and transmission loss are influenced by the aerodynamic pressure and maximum values are observed at CAP and nature of core does not influence the acoustic responses. Acoustic response is significantly influenced by the type of fiber, GNP-distribution pattern, and nature of core. However, the acoustic response is not influenced by the layup scheme.

研究了三相聚合物/石墨烯纳米片(GNP)/生物激发纤维（TP-PGF）复合材料面层的四边形增声芯夹层板（ACSP）在气动压力影响下的振声响应和传声损失特性。面板采用分层结构建模，利用汉密尔顿原理建立控制方程。采用微分求积法（DQM）求解，采用瑞利积分法分析声响应。研究了仿生铺层方案、GNP和纤维的质量分数、GNP分布模式、不同纤维（玻璃、碳和凯夫拉）、芯（负、零和正）和表面材料（各向同性和TP-PGF仿生复合材料）的泊松比等参数的影响。夹层板的临界气动压力（CAP）受仿生铺层方案的性质、GNP与纤维的质量分数、纤维、面板的GNP分布方式和芯材的泊松比等因素的显著影响。堆芯具有NPR的面板具有较高的CAP值。声响应如声功率级和透射损失受气动压力的影响，在CAP处观察到最大值，堆芯的性质不影响声学响应。光纤类型、gnp分布模式和芯层性质对声响应有显著影响。然而，声响应不受铺层方案的影响。

{"title":"Vibration and acoustic response characteristics of re-entrant auxetic core quadrilateral sandwich panel with multi-phase composites facing under supersonic flow","authors":"Vinay Kumar Prajapati , Jeyaraj Pitchaimani , Lenin Babu Mailan Chinnapandi","doi":"10.1016/j.tws.2025.114419","DOIUrl":"10.1016/j.tws.2025.114419","url":null,"abstract":"<div><div>Vibro-acoustics response and sound transmission loss (STL) characteristics of quadrilateral auxetic core sandwich panel (ACSP) having three-phase polymer/graphene nanoplatelets (GNP)/bio-inspired fiber (TP-PGF) composite facings under the influence of aerodynamic pressure is presented. Panel is modeled as layered structure and Hamilton’s principle is utilized to develop the governing equations. The solution is obtained using differential quadrature method (DQM) and acoustic response is analyzed using Rayleigh integral. The effects of various parameters, including bio-inspired layup scheme, mass fraction of GNP and fiber, GNP-distribution pattern, different fibers (Glass, Carbon and Kevlar), Poisson’s ratio of core (negative, zero, and positive) and facing material (isotropic and TP-PGF bio-inspired composite) are studied. Critical aerodynamic pressure (CAP) of sandwich panel is significantly influenced by the nature of bio-inspired layup scheme, mass fraction of GNP and fiber, fibers, GNP-distribution pattern of facings and core’s Poisson’s ratio. Panel with core having NPR provides the higher value of CAP. The acoustic responses such as sound power level and transmission loss are influenced by the aerodynamic pressure and maximum values are observed at CAP and nature of core does not influence the acoustic responses. Acoustic response is significantly influenced by the type of fiber, GNP-distribution pattern, and nature of core. However, the acoustic response is not influenced by the layup scheme.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"220 ","pages":"Article 114419"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145791289","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}

引用次数: 0

Experimental and analytical investigation on aluminium toroidal pressure vessel subjected to internal pressure 内压作用下铝环形压力容器的实验与分析研究

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114422

Mohan Krishna Paleti , Suriya Prakash S , V. Narayanamurthy

Toroidal pressure vessels (TPVs) are known to have better structural efficiency than cylindrical pressure vessels. Previous research has investigated TPVs made of steel and titanium. The performance of TPV made of aluminium alloy AA6061 is investigated by conducting hydrostatic experiments. A numerical model is developed using ABAQUS to predict the burst pressure of aluminium TPV by considering the thickness variations resulting from manufacturing tolerances. In addition, the degradation in material properties due to welding is incorporated by considering the local constitutive relation of the aluminium determined from tensile tests using the digital image correlation technique. Furthermore, the experimental and numerical failure pressures of the TPV are compared with the analytical predictions. It is found that the developed numerical model predicts the strain behaviour of the TPV (i.e., prediction of strain variation along the meridian) and the failure pressure with an accuracy of 7.2%. A parametric study is conducted to understand the effect of ratio of toroidal and meridional radii (

R / r

) on failure pressure, burst location, and strain behaviour.

环形压力容器比圆柱形压力容器具有更好的结构效率。之前的研究已经研究了由钢和钛制成的TPVs。通过流体静力试验研究了AA6061铝合金TPV的性能。利用ABAQUS建立了考虑制造公差引起的厚度变化的铝TPV破裂压力的数值模型。此外，通过考虑使用数字图像相关技术从拉伸试验中确定的铝的局部本构关系，考虑了焊接引起的材料性能退化。此外，还将TPV的实验破坏压力和数值破坏压力与分析预测结果进行了比较。结果表明，所建立的数值模型对TPV的应变行为（即沿子午线应变变化的预测）和破坏压力的预测精度为7.2%。为了了解环向半径和子午半径之比（R/ R）对破坏压力、破裂位置和应变行为的影响，进行了参数化研究。

{"title":"Experimental and analytical investigation on aluminium toroidal pressure vessel subjected to internal pressure","authors":"Mohan Krishna Paleti , Suriya Prakash S , V. Narayanamurthy","doi":"10.1016/j.tws.2025.114422","DOIUrl":"10.1016/j.tws.2025.114422","url":null,"abstract":"<div><div>Toroidal pressure vessels (TPVs) are known to have better structural efficiency than cylindrical pressure vessels. Previous research has investigated TPVs made of steel and titanium. The performance of TPV made of aluminium alloy AA6061 is investigated by conducting hydrostatic experiments. A numerical model is developed using ABAQUS to predict the burst pressure of aluminium TPV by considering the thickness variations resulting from manufacturing tolerances. In addition, the degradation in material properties due to welding is incorporated by considering the local constitutive relation of the aluminium determined from tensile tests using the digital image correlation technique. Furthermore, the experimental and numerical failure pressures of the TPV are compared with the analytical predictions. It is found that the developed numerical model predicts the strain behaviour of the TPV (i.e., prediction of strain variation along the meridian) and the failure pressure with an accuracy of 7.2%. A parametric study is conducted to understand the effect of ratio of toroidal and meridional radii (<span><math><mrow><mi>R</mi><mo>/</mo><mi>r</mi></mrow></math></span>) on failure pressure, burst location, and strain behaviour.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114422"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842763","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}

引用次数: 0

Semi-analytical modeling and vibration analysis of thin-walled plate structures with arbitrary geometric profiles 任意几何轮廓薄壁板结构的半解析建模与振动分析

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114420

Chen-Guang Wang , Xu-Yuan Song , Ye-Wei Zhang , Qing-Kai Han , Li-Qun Chen

Based on the Rayleigh–Ritz method, this study proposes a multidimensional region discrete mapping (MRDM) method for the dynamic modeling of thin-walled plate structures with arbitrary geometric profiles, aiming to overcome the limitations of traditional theoretical modeling methods, which are only applicable to regular geometries. The structures are discretized into a uniformly spaced array of data points, facilitating the description of complex geometric contours using mathematical formulas. Simultaneously, a series of discretized orthogonal displacement tolerance function arrays, incorporating weighted maps of the geometric surface functions, are constructed using the modified discrete recurrence formula to accurately approximate the modal shapes of plates with arbitrary geometric profiles. The curved surface features of the special-shaped plate structure are transformed into a two-dimensional discretized energy array through geometric mapping, and the global energy of the structure is calculated using the weighted numerical integration method. The Rayleigh–Ritz method is employed to determine the modal shapes and response of structures with arbitrary geometric profiles. Then, a series of investigations was conducted to confirm the impact of key parameters on the convergence, accuracy, and efficiency of MRDM calculations. On that basis, several specific examples were provided to demonstrate the excellent performance of the MRDM method in dealing with plates with arbitrary shapes, nonuniform thicknesses, and complex constrained boundary conditions.

基于Rayleigh-Ritz方法，针对传统理论建模方法仅适用于规则几何形状的局限性，提出了一种适用于任意几何轮廓薄壁板结构动态建模的多维区域离散映射（MRDM）方法。这些结构被离散成均匀间隔的数据点阵列，便于使用数学公式描述复杂的几何轮廓。同时，利用改进的离散递推公式构造了一系列包含几何曲面函数加权映射的离散正交位移容差函数阵列，以精确逼近任意几何轮廓板的模态振型。通过几何映射将异形板结构的曲面特征转化为二维离散能量阵列，采用加权数值积分法计算结构的整体能量。采用瑞利-里兹法确定了具有任意几何轮廓的结构的模态振型和响应。然后，进行了一系列的研究，以确定关键参数对MRDM计算的收敛性、精度和效率的影响。在此基础上，给出了几个具体的算例，证明了MRDM方法在处理任意形状、非均匀厚度和复杂约束边界条件下的板的优异性能。

{"title":"Semi-analytical modeling and vibration analysis of thin-walled plate structures with arbitrary geometric profiles","authors":"Chen-Guang Wang , Xu-Yuan Song , Ye-Wei Zhang , Qing-Kai Han , Li-Qun Chen","doi":"10.1016/j.tws.2025.114420","DOIUrl":"10.1016/j.tws.2025.114420","url":null,"abstract":"<div><div>Based on the Rayleigh–Ritz method, this study proposes a multidimensional region discrete mapping (MRDM) method for the dynamic modeling of thin-walled plate structures with arbitrary geometric profiles, aiming to overcome the limitations of traditional theoretical modeling methods, which are only applicable to regular geometries. The structures are discretized into a uniformly spaced array of data points, facilitating the description of complex geometric contours using mathematical formulas. Simultaneously, a series of discretized orthogonal displacement tolerance function arrays, incorporating weighted maps of the geometric surface functions, are constructed using the modified discrete recurrence formula to accurately approximate the modal shapes of plates with arbitrary geometric profiles. The curved surface features of the special-shaped plate structure are transformed into a two-dimensional discretized energy array through geometric mapping, and the global energy of the structure is calculated using the weighted numerical integration method. The Rayleigh–Ritz method is employed to determine the modal shapes and response of structures with arbitrary geometric profiles. Then, a series of investigations was conducted to confirm the impact of key parameters on the convergence, accuracy, and efficiency of MRDM calculations. On that basis, several specific examples were provided to demonstrate the excellent performance of the MRDM method in dealing with plates with arbitrary shapes, nonuniform thicknesses, and complex constrained boundary conditions.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114420"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842276","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}

引用次数: 0

Isogeometric analysis for non-manifold stiffened arbitrary surfaces via subdivision-based nested model (SNM) 基于细分嵌套模型（SNM）的非流形加筋任意曲面等几何分析

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-18 DOI: 10.1016/j.tws.2025.114378

Lingzhi Jin , Zhengyang Zhang , Yu Wang , Shuhao Ma , Peng Hao

Stiffened Thin-Walled Struct.ures are widely used as load-bearing components in engineering due to their excellent mechanical properties. When modeling complex stiffened shells, traditional spline models face issues with piecewise splicing and difficulties in ensuring watertightness. While subdivision modeling provides an effective solution, in dealing with non-manifold stiffened surface structures, it both requires highly detailed meshes and is prone to mesh distortion. To address these challenges, this paper proposes a novel modeling method for stiffened arbitrary surfaces using the subdivision-based nested model (SNM) and extends subdivision-based isogeometric analysis (IGA) to this model. In terms of model representation, the SNM proposed based on the nested idea adopts Catmull-Clark subdivision surfaces to describe the skins and spline control curves explicitly defined on the control meshes to represent stiffeners. Additionally, through its implicit mapping, SNM enables intuitive modeling and precise description of complex stiffened surfaces. In particular, to satisfy the continuity requirements, a geometric continuity correction algorithm is proposed to ensure

G^{1}

continuity of stiffener curves on complex surfaces. In terms of numerical analysis, built on the IGA framework, a degenerate shell element formulation based on the Catmull-Clark subdivision is implemented. To achieve automatic strong coupling analysis, a degenerate stiffener element suitable for SNM is implemented, which integrates modeling and analysis while reducing the degrees of freedom (DOFs). Three common linear analysis formats for stiffened Thin-Walled Struct.ures, including static, buckling, and free vibration, are established. The effectiveness and robustness of the proposed method are fully verified by two benchmarks and three engineering examples.

加劲薄壁结构。金属具有优良的力学性能，在工程中被广泛用作承重构件。传统的样条模型在建模复杂的加筋壳时，面临着分段拼接和水密性难以保证的问题。虽然细分建模提供了一种有效的解决方案，但在处理非流形强化表面结构时，它既需要非常详细的网格，又容易产生网格畸变。为了解决这些问题，本文提出了一种新的基于细分的嵌套模型（SNM）的加筋任意曲面建模方法，并将基于细分的等几何分析（IGA）扩展到该模型中。在模型表示方面，基于嵌套思想提出的SNM采用Catmull-Clark细分曲面来描述蒙皮，并在控制网格上明确定义样条控制曲线来表示加强筋。此外，通过其隐式映射，SNM能够直观地建模和精确地描述复杂的加筋表面。特别为满足连续性要求，提出了一种几何连续性校正算法，以保证在复杂曲面上加筋曲线的G1连续性。在数值分析方面，基于IGA框架，实现了基于Catmull-Clark细分的简并壳元公式。为了实现自动强耦合分析，设计了一种适合于SNM的退化加劲单元，将建模和分析集成在一起，同时降低了自由度。加筋薄壁结构的三种常用线性分析格式。建立了静态、屈曲和自由振动等参数。通过两个基准测试和三个工程实例，充分验证了该方法的有效性和鲁棒性。

{"title":"Isogeometric analysis for non-manifold stiffened arbitrary surfaces via subdivision-based nested model (SNM)","authors":"Lingzhi Jin , Zhengyang Zhang , Yu Wang , Shuhao Ma , Peng Hao","doi":"10.1016/j.tws.2025.114378","DOIUrl":"10.1016/j.tws.2025.114378","url":null,"abstract":"<div><div>Stiffened Thin-Walled Struct.ures are widely used as load-bearing components in engineering due to their excellent mechanical properties. When modeling complex stiffened shells, traditional spline models face issues with piecewise splicing and difficulties in ensuring watertightness. While subdivision modeling provides an effective solution, in dealing with non-manifold stiffened surface structures, it both requires highly detailed meshes and is prone to mesh distortion. To address these challenges, this paper proposes a novel modeling method for stiffened arbitrary surfaces using the subdivision-based nested model (SNM) and extends subdivision-based isogeometric analysis (IGA) to this model. In terms of model representation, the SNM proposed based on the nested idea adopts Catmull-Clark subdivision surfaces to describe the skins and spline control curves explicitly defined on the control meshes to represent stiffeners. Additionally, through its implicit mapping, SNM enables intuitive modeling and precise description of complex stiffened surfaces. In particular, to satisfy the continuity requirements, a geometric continuity correction algorithm is proposed to ensure <span><math><msup><mrow><mi>G</mi></mrow><mn>1</mn></msup></math></span> continuity of stiffener curves on complex surfaces. In terms of numerical analysis, built on the IGA framework, a degenerate shell element formulation based on the Catmull-Clark subdivision is implemented. To achieve automatic strong coupling analysis, a degenerate stiffener element suitable for SNM is implemented, which integrates modeling and analysis while reducing the degrees of freedom (DOFs). Three common linear analysis formats for stiffened Thin-Walled Struct.ures, including static, buckling, and free vibration, are established. The effectiveness and robustness of the proposed method are fully verified by two benchmarks and three engineering examples.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114378"},"PeriodicalIF":6.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885352","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}

引用次数: 0

Synergistic enhancement of 6061 Al/CFRTP joints via laser texturing and chemical etching process for fused deposition modeling 6061 Al/CFRTP接头激光织构与化学蚀刻协同增强熔敷成型

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-17 DOI: 10.1016/j.tws.2025.114412

Haoran Liu , Shijia Wang , Jianhui Su , Chunlin Qin , Haoyue Li , Qian Zhi , Caiwang Tan , Bo Chen , Xiaoguo Song

Integrated metal/thermoplastic manufacturing is the trend for industrial applications due to lightweight. However, the joining reliability of metal and carbon fiber reinforced thermoplastic (CFRTP) hybrid joints is relatively low owing to the inherent physical incompatibility, which constrains the development of lightweight integrated components. In this work, the micro-cross pits with a certain direction were fabricated by laser texturing process on the 6061 Al surface, and the nanostructure was processed by chemical etching process to enhance the 6061 Al/CFRTP nylon 6 (PA6) hybrid joints. The surface free energy and roughness were significantly increased at the bonding interface. The tensile-shear strength of 6061 Al/CFRTP joint substantially increased, then gradually declined with the increase of chemical etching time. The results showed that the Al-O-C bond was formatted on bonding interface and the diffusion of elements at the interface of dual-scale processed samples was wider, promoting the joining strength at the joining interface. The laser textured sample with the optimized chemical etching time (30 s) exhibited the maximum shear-tensile strength of 11.23 MPa, which increased by 348% relative to untreated cases. The integrated preparation of 6061 Al/CFRTP joints was achieved via the fused deposition modeling process with dual-scale modification modulation, which breaks through the single structure limitation of traditional metal/thermoplastics joints.

由于重量轻，集成金属/热塑性制造是工业应用的趋势。然而，金属与碳纤维增强热塑性塑料（CFRTP）混合接头由于其固有的物理不相容性，连接可靠性较低，制约了轻量化一体化部件的发展。本文采用激光织构法在6061 Al表面制造具有一定方向的微交叉坑，并采用化学蚀刻工艺加工纳米结构，以增强6061 Al/CFRTP尼龙6 （PA6）杂化接头。在键合界面处，表面自由能和粗糙度显著增加。随着化学腐蚀时间的增加，6061 Al/CFRTP接头的抗拉剪切强度先大幅增加，后逐渐下降。结果表明：Al-O-C键在键合界面上形成，双尺度处理试样在界面处元素扩散更广，提高了连接界面处的连接强度；经过优化的化学刻蚀时间（30 s）后，激光织构样品的最大抗剪强度为11.23 MPa，比未处理的样品提高了348%。采用双尺度改性调制熔融沉积成型工艺，实现了6061 Al/CFRTP接头的一体化制备，突破了传统金属/热塑性塑料接头单一结构的局限。

{"title":"Synergistic enhancement of 6061 Al/CFRTP joints via laser texturing and chemical etching process for fused deposition modeling","authors":"Haoran Liu , Shijia Wang , Jianhui Su , Chunlin Qin , Haoyue Li , Qian Zhi , Caiwang Tan , Bo Chen , Xiaoguo Song","doi":"10.1016/j.tws.2025.114412","DOIUrl":"10.1016/j.tws.2025.114412","url":null,"abstract":"<div><div>Integrated metal/thermoplastic manufacturing is the trend for industrial applications due to lightweight. However, the joining reliability of metal and carbon fiber reinforced thermoplastic (CFRTP) hybrid joints is relatively low owing to the inherent physical incompatibility, which constrains the development of lightweight integrated components. In this work, the micro-cross pits with a certain direction were fabricated by laser texturing process on the 6061 Al surface, and the nanostructure was processed by chemical etching process to enhance the 6061 Al/CFRTP nylon 6 (PA6) hybrid joints. The surface free energy and roughness were significantly increased at the bonding interface. The tensile-shear strength of 6061 Al/CFRTP joint substantially increased, then gradually declined with the increase of chemical etching time. The results showed that the Al-O-C bond was formatted on bonding interface and the diffusion of elements at the interface of dual-scale processed samples was wider, promoting the joining strength at the joining interface. The laser textured sample with the optimized chemical etching time (30 s) exhibited the maximum shear-tensile strength of 11.23 MPa, which increased by 348% relative to untreated cases. The integrated preparation of 6061 Al/CFRTP joints was achieved via the fused deposition modeling process with dual-scale modification modulation, which breaks through the single structure limitation of traditional metal/thermoplastics joints.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"220 ","pages":"Article 114412"},"PeriodicalIF":6.6,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790929","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}

引用次数: 0

Inverse design of growth-inspired disordered metamaterials with programmable nonlinear force deflection responses 具有可编程非线性力挠度响应的生长激发无序超材料的反设计

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-17 DOI: 10.1016/j.tws.2025.114418

Junwei Chen , Yu Li , Xiao Kang , Wen Yao

Inspired by biological materials, aperiodicity and disorder significantly expand the design freedom of mechanical structures and prove effective in optimizing linear elastic and elastoplastic properties. However, customizing the nonlinear force deflection responses of disordered metamaterials under dynamic impact remains challenging due to the vast design space, irregular structural forms, and complex structure-property relationships. In this work, a novel framework for the design of disordered metamaterials is proposed, consisting of a forward prediction network and an inverse design network, to enable programmable stress-strain behaviors. The disordered metamaterials are generated through a virtual growth program, which assembles predefined building blocks in a stochastic yet controllable manner. Unlike conventional methods, the proposed framework enables diverse equivalent stress-strain responses solely by altering the spatial distribution of building blocks, without changing the generation frequency. In addition, four distinct types of representative structures are identified through investigation of the energy absorption performance of disordered metamaterials. Structural chamber graphs and nodes with different coordination numbers are introduced to elucidate the mechanism by which the spatial distribution of building blocks affects macroscopic mechanical behavior. Furthermore, the inverse design framework generates an energy-absorbing structure that outperforms the maximum-SEA_v sample in the dataset by 8.41%. Finally, dynamic experiments are conducted to validate the effectiveness of the proposed method. This framework provides a new pathway for realizing complex, predefined nonlinear force deflection responses and advances the data-driven design of disordered metamaterials.

受生物材料的启发，非周期性和无序性极大地扩展了机械结构的设计自由度，并被证明是优化线弹性和弹塑性性能的有效方法。然而，由于无序超材料的设计空间巨大、结构形式不规则、结构-性能关系复杂，定制动态冲击下的非线性力挠度响应仍然具有挑战性。在这项工作中，提出了一个新的框架设计无序超材料，包括一个正向预测网络和一个逆向设计网络，以实现可编程的应力-应变行为。无序的超材料是通过虚拟生长程序生成的，该程序以随机但可控的方式组装预定义的构建块。与传统方法不同，所提出的框架仅通过改变构建块的空间分布就能实现不同的等效应力-应变响应，而不改变产生频率。此外，通过对无序超材料吸能性能的研究，确定了四种不同类型的代表性结构。引入不同配位数的结构室图和节点，阐明了砌块空间分布对宏观力学行为的影响机制。此外，逆设计框架生成的吸能结构比数据集中的最大seav样本性能高8.41%。最后，通过动态实验验证了所提方法的有效性。该框架为实现复杂的、预定义的非线性力挠度响应提供了新的途径，并推动了无序超材料的数据驱动设计。

{"title":"Inverse design of growth-inspired disordered metamaterials with programmable nonlinear force deflection responses","authors":"Junwei Chen , Yu Li , Xiao Kang , Wen Yao","doi":"10.1016/j.tws.2025.114418","DOIUrl":"10.1016/j.tws.2025.114418","url":null,"abstract":"<div><div>Inspired by biological materials, aperiodicity and disorder significantly expand the design freedom of mechanical structures and prove effective in optimizing linear elastic and elastoplastic properties. However, customizing the nonlinear force deflection responses of disordered metamaterials under dynamic impact remains challenging due to the vast design space, irregular structural forms, and complex structure-property relationships. In this work, a novel framework for the design of disordered metamaterials is proposed, consisting of a forward prediction network and an inverse design network, to enable programmable stress-strain behaviors. The disordered metamaterials are generated through a virtual growth program, which assembles predefined building blocks in a stochastic yet controllable manner. Unlike conventional methods, the proposed framework enables diverse equivalent stress-strain responses solely by altering the spatial distribution of building blocks, without changing the generation frequency. In addition, four distinct types of representative structures are identified through investigation of the energy absorption performance of disordered metamaterials. Structural chamber graphs and nodes with different coordination numbers are introduced to elucidate the mechanism by which the spatial distribution of building blocks affects macroscopic mechanical behavior. Furthermore, the inverse design framework generates an energy-absorbing structure that outperforms the maximum-SEA<sub>v</sub> sample in the dataset by 8.41%. Finally, dynamic experiments are conducted to validate the effectiveness of the proposed method. This framework provides a new pathway for realizing complex, predefined nonlinear force deflection responses and advances the data-driven design of disordered metamaterials.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"220 ","pages":"Article 114418"},"PeriodicalIF":6.6,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840474","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}

引用次数: 0

A new modified strain gradient theory with anisotropy matrices and thickness-dependent contact models for impact analysis of composite microplates exposed to various shapes of indenters 基于各向异性矩阵和厚度相关接触模型的新型修正应变梯度理论用于复合材料微板在不同形状压头下的冲击分析

IF 6.6 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures

Pub Date : 2025-12-17 DOI: 10.1016/j.tws.2025.114409

M. Shariyat

The present article provides crucial insights into the essential but commonly neglected concepts in the development of the contact models, the application of the nonlocal theories, and the integration of the micro-dimensional orthotropy/anisotropy matrices in thin-walled structures, through investigation of the low-velocity impact behaviors of the composite microplates. A new modified strain gradient theory with five categories of scalar- and matrix-type sets of micro-dimension anisotropy multipliers is proposed. The original modified strain gradient theory was valid only for isotropic structures. Instead of using the common Hertz half-space contact law, new contact models that account for the material orthotropy, micro-thickness, boundary conditions of the plate, and the shape (spherical, flat-ended cylindrical, and conical) of the indenter tip are proposed. The nonlinear governing equations are found through Hamilton’s principle, weighted residual finite element method, adequate decomposition of the nonlinear terms, and a successive approximation-based Runge-Kutta time integration scheme. Choosing nonidentical micro-dimension coefficients is also examined. The predictions of the modified strain gradient theory for the time histories of the contact force and lateral deflection are compared with those of the modified couple stress theory, nonlocal strain gradient theory, and classical plate theory. While the predictions of the present contact model were closer to the experimental results than the Hertz contact model, it is proven that the nonlocal-elasticity-based theories, such as the nonlocal strain gradient theory, predict an extremely compliant microstructure and lead to erroneous results, in contrast to the modified couple stress and the more accurate modified strain gradient theories. Although the proposed anisotropy micro-dimension matrices offer the most accurate results, using the concept of the closest isotropic material to an orthotropic material may lead to highly accurate results, too. Moreover, the cylindrical indenter leads to the largest contact force, followed by the spherical and conical indenters. Conversely, the lateral deflection and contact time exhibit the reverse order. Among the three micro-dimension coefficients, the l₂ coefficient showed the dominant effect on the impact responses.

本文通过对复合材料微孔板的低速冲击行为的研究，为接触模型的发展、非局部理论的应用以及薄壁结构中微观正交异性/各向异性矩阵的集成提供了重要的但通常被忽视的概念。提出了一种新的修正应变梯度理论，该理论包含五类微维各向异性乘法器的标量和矩阵型集合。原来的修正应变梯度理论只适用于各向同性结构。提出了考虑材料正交异性、微厚度、板的边界条件以及压头尖端形状（球形、平头圆柱形和圆锥形）的新型接触模型，取代了常用的赫兹半空间接触定律。通过Hamilton原理、加权残差有限元法、非线性项的充分分解和基于逐次逼近的龙格-库塔时间积分格式得到非线性控制方程。本文还研究了不同微尺度系数的选择。将修正应变梯度理论对接触力和侧向挠度时程的预测结果与修正偶应力理论、非局部应变梯度理论和经典板理论进行了比较。虽然该接触模型的预测结果比Hertz接触模型更接近实验结果，但证明了基于非局部弹性的理论，如非局部应变梯度理论，预测了一个非常柔韧的微观结构，并导致错误的结果，与修正的耦合应力和更精确的修正应变梯度理论相反。虽然提出的各向异性微尺寸矩阵提供了最精确的结果，但使用最接近各向同性材料的概念也可能导致高度精确的结果。圆柱压头产生的接触力最大，其次是球形压头和锥形压头。相反，侧向挠度和接触时间呈现相反的顺序。在3个微观系数中，l2系数对冲击响应的影响最为显著。

{"title":"A new modified strain gradient theory with anisotropy matrices and thickness-dependent contact models for impact analysis of composite microplates exposed to various shapes of indenters","authors":"M. Shariyat","doi":"10.1016/j.tws.2025.114409","DOIUrl":"10.1016/j.tws.2025.114409","url":null,"abstract":"<div><div>The present article provides crucial insights into the essential but commonly neglected concepts in the development of the contact models, the application of the nonlocal theories, and the integration of the micro-dimensional orthotropy/anisotropy matrices in thin-walled structures, through investigation of the low-velocity impact behaviors of the composite microplates. A new modified strain gradient theory with five categories of scalar- and matrix-type sets of micro-dimension anisotropy multipliers is proposed. The original modified strain gradient theory was valid only for isotropic structures. Instead of using the common Hertz half-space contact law, new contact models that account for the material orthotropy, micro-thickness, boundary conditions of the plate, and the shape (spherical, flat-ended cylindrical, and conical) of the indenter tip are proposed. The nonlinear governing equations are found through Hamilton’s principle, weighted residual finite element method, adequate decomposition of the nonlinear terms, and a successive approximation-based Runge-Kutta time integration scheme. Choosing nonidentical micro-dimension coefficients is also examined. The predictions of the modified strain gradient theory for the time histories of the contact force and lateral deflection are compared with those of the modified couple stress theory, nonlocal strain gradient theory, and classical plate theory. While the predictions of the present contact model were closer to the experimental results than the Hertz contact model, it is proven that the nonlocal-elasticity-based theories, such as the nonlocal strain gradient theory, predict an extremely compliant microstructure and lead to erroneous results, in contrast to the modified couple stress and the more accurate modified strain gradient theories. Although the proposed anisotropy micro-dimension matrices offer the most accurate results, using the concept of the closest isotropic material to an orthotropic material may lead to highly accurate results, too. Moreover, the cylindrical indenter leads to the largest contact force, followed by the spherical and conical indenters. Conversely, the lateral deflection and contact time exhibit the reverse order. Among the three micro-dimension coefficients, the <em>l</em><sub>2</sub> coefficient showed the dominant effect on the impact responses.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"221 ","pages":"Article 114409"},"PeriodicalIF":6.6,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842765","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}

引用次数: 0