International Journal of Solids and Structures最新文献

Multiaxial yield behavior of transversely isotropic closed-cell aluminum foams

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-28 DOI: 10.1016/j.ijsolstr.2025.113322

Erdong Wang , Jingjing Cai , Xintao Huo , Xiao Guo

Mechanical properties of metallic foams will exhibit direction-dependency when the cell shape anisotropy is generated during the manufacturing process. To provide effective design and analysis for the foam-based structures in engineering applications, it is essential to gain a robust understanding of the multiaxial yield properties of anisotropic foams. High-fidelity Voronoi foam model is constructed based on the statistical microstructure information that are measured using micro-CT technique. Transversely isotropic Voronoi foams are generated and adopted to conduct virtual multiaxial experiments. Numerical results show that large plastic deformation is mainly concentrated nearby the rigid platens in uniaxial, biaxial and triaxial compression, while a shear-like deformation localization bands is formed in the compression-shear loading. Sufficient yield points are determined in multiaxial loadings as per a total dissipation energy-based criterion. Numerical isotropic yield surfaces are plotted in the mean-effective stress plane and expand with increasing relative density, which can be well fitted using Zhang yield criteria. For transversely isotropic foams, the dispersion degree of yield points in the mean-effective stress plane is increased with increasing geometric stretch factor. The transversely isotropic yield surfaces are scaled proportionally with the uniaxial yield strength along transverse direction. The extended Hill’s anisotropic yield criterion can generally capture initial yielding behavior of transversely isotropic foams with different anisotropy coefficients and relative densities, outperforming other isotropic yield criteria.

{"title":"Multiaxial yield behavior of transversely isotropic closed-cell aluminum foams","authors":"Erdong Wang , Jingjing Cai , Xintao Huo , Xiao Guo","doi":"10.1016/j.ijsolstr.2025.113322","DOIUrl":"10.1016/j.ijsolstr.2025.113322","url":null,"abstract":"<div><div>Mechanical properties of metallic foams will exhibit direction-dependency when the cell shape anisotropy is generated during the manufacturing process. To provide effective design and analysis for the foam-based structures in engineering applications, it is essential to gain a robust understanding of the multiaxial yield properties of anisotropic foams. High-fidelity Voronoi foam model is constructed based on the statistical microstructure information that are measured using micro-CT technique. Transversely isotropic Voronoi foams are generated and adopted to conduct virtual multiaxial experiments. Numerical results show that large plastic deformation is mainly concentrated nearby the rigid platens in uniaxial, biaxial and triaxial compression, while a shear-like deformation localization bands is formed in the compression-shear loading. Sufficient yield points are determined in multiaxial loadings as per a total dissipation energy-based criterion. Numerical isotropic yield surfaces are plotted in the mean-effective stress plane and expand with increasing relative density, which can be well fitted using Zhang yield criteria. For transversely isotropic foams, the dispersion degree of yield points in the mean-effective stress plane is increased with increasing geometric stretch factor. The transversely isotropic yield surfaces are scaled proportionally with the uniaxial yield strength along transverse direction. The extended Hill’s anisotropic yield criterion can generally capture initial yielding behavior of transversely isotropic foams with different anisotropy coefficients and relative densities, outperforming other isotropic yield criteria.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"314 ","pages":"Article 113322"},"PeriodicalIF":3.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

An anisotropic constitutive relationship by a series of 8 chain models

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-27 DOI: 10.1016/j.ijsolstr.2025.113288

Libin Yang , Teng Long , Lixiang Yang

Hyperelastic models have been widely used to model polymers and soft tissues. However, most hyperelastic models are phenomenological material models. Based on statistical mechanics and molecular chain configuration, the 8 chain model or Arruda-Boyce model is a physical model which can be used to understand how microstructures of chains affect macroscopic mechanical properties of polymers and soft tissues. Mechanical properties of many polymers and soft tissues are directional dependent. Polymer matrix can be reinforced by fibers. For soft tissues, ligaments and tendons will lead to anisotropic properties. Since matrix and reinforcements are composed of similar microstructural molecular chains, they can be modeled by using the same mathematical model. In this paper, a series of 8 chain models is used to understand composite properties. That is, an isotropic 8 chain model will be used to model matrix and anisotropic 8 chain models will be used to model fibers. Replacing

I_{1}

in isotropic 8 chain model with

I_{4}

in anisotropic 8 chain model is physically corresponding to changing representative 8 chain cubic cell to 8 chain slender cell. This treatment not only simplifies exist anisotropic mathematical structures but also keeps microscopic physics of the 8 chain model unchanged.

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引用次数: 0

Prediction of necking instability under tension-shear stress state based on updated modified maximum force criterion 基于最新修正的最大力准则预测拉伸剪切应力状态下的颈缩不稳定性

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-26 DOI: 10.1016/j.ijsolstr.2025.113319

Nan Gu , Wen Zhang , Deyong Zhou , Meiying Yang , Xinghao Lu , Xincun Zhuang , Zhen Zhao

During the process from sheet forming to failure, the material might undergo uniform deformation, diffused necking (DN), localized necking (LN), and finally ductile fracture (DF). Researchers have found that a competitive mechanism exists between the LN-induced failure mode and DF-induced failure mode in the ductile metallic material. For tension shear (TS) stress state, most studies are focused on the DF prediction. This paper is concerned with necking instability in TS region and the prediction of necking failures. An updated modified maximum force criterion (uMMFC) model is proposed by considering the effect of in-plane shear stress, in which the strain path at LN onset under TS is no longer plane strain tension but varies with the initial path. Meanwhile, the effect of through-thickness normal stress is introduced into the uMMFC model. By comparing the forming limits obtained from the uMMFC, the original MMFC and the experimental results under uniaxial tension tests and Nakajima tests, it is concluded that the uMMFC model can well predict the forming limit curve under TS. Furthermore, the uMMFC model with the introduction of strain path modification after DN demonstrates a further improvement in prediction accuracy.

{"title":"Prediction of necking instability under tension-shear stress state based on updated modified maximum force criterion","authors":"Nan Gu , Wen Zhang , Deyong Zhou , Meiying Yang , Xinghao Lu , Xincun Zhuang , Zhen Zhao","doi":"10.1016/j.ijsolstr.2025.113319","DOIUrl":"10.1016/j.ijsolstr.2025.113319","url":null,"abstract":"<div><div>During the process from sheet forming to failure, the material might undergo uniform deformation, diffused necking (DN), localized necking (LN), and finally ductile fracture (DF). Researchers have found that a competitive mechanism exists between the LN-induced failure mode and DF-induced failure mode in the ductile metallic material. For tension shear (TS) stress state, most studies are focused on the DF prediction. This paper is concerned with necking instability in TS region and the prediction of necking failures. An updated modified maximum force criterion (uMMFC) model is proposed by considering the effect of in-plane shear stress, in which the strain path at LN onset under TS is no longer plane strain tension but varies with the initial path. Meanwhile, the effect of through-thickness normal stress is introduced into the uMMFC model. By comparing the forming limits obtained from the uMMFC, the original MMFC and the experimental results under uniaxial tension tests and Nakajima tests, it is concluded that the uMMFC model can well predict the forming limit curve under TS. Furthermore, the uMMFC model with the introduction of strain path modification after DN demonstrates a further improvement in prediction accuracy.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113319"},"PeriodicalIF":3.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Deformation and energy absorption characteristics of graded auxetic metamaterials featuring peanut-shaped perforations under in-plane compression

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-25 DOI: 10.1016/j.ijsolstr.2025.113318

Zhuo Zhang, Yongpeng Lei, Hui Wang

The auxetic metamaterials perforated by peanut-shaped holes have been paid much attention recently due to the advantages in alleviating stress concentration, tuning negative Poisson’s ratio (NPR) and stiffness, and reducing material usage. However, few studies pay attention to their graded designs, which have exhibited promising applications in natural biomaterials. In this study, the innovative design of graded auxetic metamaterials featuring peanut-shaped perforations is explored, emphasizing their potential in customizing deformation and energy absorption. By exploring four distinct graded types, including unidirectional gradient (UG), inward gradient (IG), outward gradient (OG) and alternate gradient (AG) and three gradient-controlling ways, including porosity (K), shape coefficient (M), and porosity and shape coefficient changing simultaneously (KM), 12 unique graded structures are developed. The graded specimens under quasi-static compression exhibit distinct deformation behaviors. Subsequently, the graded structures are thoroughly explored by the validated finite element model and the deformation mode, dynamic Poisson’s ratio and energy absorption capacity are comprehensively investigated. Compared to the uniform structure, the distribution and quantity of NPR bands strongly depend on the perforation’s size and the gradient types. Furthermore, UG-KM can significantly amplify the NPR effect, achieving a maximum enhancement of 14.32%. In contrast, AG-K can considerably diminish the NPR effect, with a maximum reduction of 19.37%. Additionally, type OG exhibit superior energy absorption characteristics, with mean stress and specific energy absorption increasing by up to 28.89% and 46.73%, respectively. The findings provide an effective strategy for designing the auxetic metamaterials with tunable deformation and energy absorption characteristics.

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引用次数: 0

Modeling of diffusion-induced inter-/transgranular cracking in polycrystal NCM particles: Effects of external force and boundary constraints

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-23 DOI: 10.1016/j.ijsolstr.2025.113300

Yong Li , Yunpeng Guo , Yuwei Zhang , Wei Feng , Kai Zhang , Xin Wang , Fuqian Yang

Experimental results have evidenced that appropriate external forces can mitigate structural degradation and damage of active particles during electrochemical cycling of metal-ion batteries. Currently, there are few studies on structural degradation and damage of active particles under concurrent action of diffusion and external loading. Using finite-discrete element method (FDEM), we analyze diffusion-induced cracking in a polycrystal NCM (lithium nickel manganese cobalt oxide) particle under three different configurations: traction-free boundary, rigid confinement to opposite ends, and external loading to opposite ends under constant influx. The numerical results illustrate that appropriate external loading can suppress the nucleation and propagation of cracks induced by the diffusion of solute atoms and retard structural degradation/damage of polycrystal NCM particles. Increasing the amount of solute atoms and applying excessive external loading can promote the nucleation and propagation of cracks in polycrystal NCM particles due to large contact deformation and the deformation induced by the diffusion of solute atoms, which escalates structural degradation/damage of the electrodes in metal-ion batteries.

实验结果表明，在金属离子电池的电化学循环过程中，适当的外力可以缓解活性粒子的结构退化和损坏。目前，有关扩散和外部负载同时作用下活性颗粒结构退化和损坏的研究很少。我们采用有限离散元法（FDEM）分析了多晶 NCM（锂镍锰钴氧化物）颗粒在三种不同配置下的扩散诱导裂纹：无牵引边界、两端刚性约束和两端恒定流入的外部加载。数值结果表明，适当的外部加载可抑制溶质原子扩散引起的裂纹成核和扩展，并延缓多晶 NCM 粒子的结构退化/损坏。增加溶质原子的数量和施加过大的外部负载会因接触变形和溶质原子扩散引起的变形过大而促进多晶 NCM 颗粒裂纹的成核和扩展，从而加剧金属离子电池电极的结构退化/损坏。

{"title":"Modeling of diffusion-induced inter-/transgranular cracking in polycrystal NCM particles: Effects of external force and boundary constraints","authors":"Yong Li , Yunpeng Guo , Yuwei Zhang , Wei Feng , Kai Zhang , Xin Wang , Fuqian Yang","doi":"10.1016/j.ijsolstr.2025.113300","DOIUrl":"10.1016/j.ijsolstr.2025.113300","url":null,"abstract":"<div><div>Experimental results have evidenced that appropriate external forces can mitigate structural degradation and damage of active particles during electrochemical cycling of metal-ion batteries. Currently, there are few studies on structural degradation and damage of active particles under concurrent action of diffusion and external loading. Using finite-discrete element method (FDEM), we analyze diffusion-induced cracking in a polycrystal NCM (lithium nickel manganese cobalt oxide) particle under three different configurations: traction-free boundary, rigid confinement to opposite ends, and external loading to opposite ends under constant influx. The numerical results illustrate that appropriate external loading can suppress the nucleation and propagation of cracks induced by the diffusion of solute atoms and retard structural degradation/damage of polycrystal NCM particles. Increasing the amount of solute atoms and applying excessive external loading can promote the nucleation and propagation of cracks in polycrystal NCM particles due to large contact deformation and the deformation induced by the diffusion of solute atoms, which escalates structural degradation/damage of the electrodes in metal-ion batteries.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113300"},"PeriodicalIF":3.4,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 calibration of out-of-plane shear anisotropy parameters of sheet metal

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-23 DOI: 10.1016/j.ijsolstr.2025.113313

Bojan Starman , Tomaž Pepelnjak , Andraž Maček , Miroslav Halilovič , Sam Coppieters

The accurate description of sheet metal forming processes such as blanking, riveting, incremental forming, and ironing strongly depends on understanding the material’s through-thickness shear resistance and plastic behavior. A three-dimensional model of plastic anisotropy is required to capture this behavior, but calibrating the out-of-plane shear parameters is often challenging. Researchers frequently assume isotropy or set the in-plane and out-of-plane shear parameters equal. More advanced approaches use a crystal plasticity model, which also requires calibration based on available material texture data. In this work, we introduce an out-of-plane shear test procedure that combines a macromechanical test with digital image correlation to inversely calibrate the shear anisotropy parameters of the YLD2004-18p yield function. This method efficiently characterizes both in-plane and out-of-plane shear anisotropy in medium-thick sheet metals.

对冲裁、铆接、增量成形和熨烫等金属板材成形工艺的准确描述，在很大程度上取决于对材料厚度剪切阻力和塑性行为的理解。要捕捉这种行为，需要塑性各向异性的三维模型，但校准平面外剪切参数往往具有挑战性。研究人员经常假设各向同性或将面内和面外剪切参数设置为相等。更先进的方法是使用晶体塑性模型，这也需要根据现有的材料纹理数据进行校准。在这项工作中，我们介绍了一种平面外剪切测试程序，它将宏观力学测试与数字图像相关性相结合，对 YLD2004-18p 屈服函数的剪切各向异性参数进行反向校准。这种方法能有效地表征中厚金属板的面内和面外剪切各向异性。

引用次数: 0

Energy-based PINNs using the element integral approach and their enhancement for solid mechanics problems

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-23 DOI: 10.1016/j.ijsolstr.2025.113315

Junwei Chen , Jianxiang Ma , Zhi Zhao , Xiaoping Zhou

Despite the growing interest in physics-informed neural networks (PINNs) for computational mechanics, significant challenges remain in their widespread application. This work proposes an energy-based PINN method rooted in the principle of virtual work, which states that the external work done on a system is equal to its strain energy. This proposed method discretizes the model into nodes and constructs elements based on these nodes. The strain energy of each element is computed through numerical integration, and the total strain energy of the model is obtained by summing these elemental contributions. Simultaneously, the external work is calculated based on the nodal forces. These calculations, combined with the principle of virtual work, allow for the definition of the model’s physical properties. A deep neural network (DNN) is then trained to map the model’s coordinates to their corresponding displacements, utilizing the defined physical properties. Furthermore, this paper proposes a method to accelerate the learning process of energy-based PINNs by using a simpler and converged model to speed up convergence and to improve the overall accuracy of more complex models. Numerical results demonstrate that the proposed approach effectively solves stress concentration and singularity problems in solid mechanics with high accuracy.

{"title":"Energy-based PINNs using the element integral approach and their enhancement for solid mechanics problems","authors":"Junwei Chen , Jianxiang Ma , Zhi Zhao , Xiaoping Zhou","doi":"10.1016/j.ijsolstr.2025.113315","DOIUrl":"10.1016/j.ijsolstr.2025.113315","url":null,"abstract":"<div><div>Despite the growing interest in physics-informed neural networks (PINNs) for computational mechanics, significant challenges remain in their widespread application. This work proposes an energy-based PINN method rooted in the principle of virtual work, which states that the external work done on a system is equal to its strain energy. This proposed method discretizes the model into nodes and constructs elements based on these nodes. The strain energy of each element is computed through numerical integration, and the total strain energy of the model is obtained by summing these elemental contributions. Simultaneously, the external work is calculated based on the nodal forces. These calculations, combined with the principle of virtual work, allow for the definition of the model’s physical properties. A deep neural network (DNN) is then trained to map the model’s coordinates to their corresponding displacements, utilizing the defined physical properties. Furthermore, this paper proposes a method to accelerate the learning process of energy-based PINNs by using a simpler and converged model to speed up convergence and to improve the overall accuracy of more complex models. Numerical results demonstrate that the proposed approach effectively solves stress concentration and singularity problems in solid mechanics with high accuracy.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113315"},"PeriodicalIF":3.4,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Constitutive modelling and validating of annealed copper under various stress states, strain rates and temperatures

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-22 DOI: 10.1016/j.ijsolstr.2025.113312

Yutian Du , Zejian Xu , Hongzhi Hu , Mengyu Su , Ang Hu , Fenglei Huang

Metallic materials and structures are often subjected to a wide range of strain, strain rate, temperature and stress state during the engineering application. In order to study the plastic and deformation characteristics of metallic materials under complex stress states, it is necessary to use a constitutive model that considers the effects of stress states. Based on shear specimens suitable for hydraulic Instron testing machines and Hopkinson bar systems (SHPB and SHTB), the compression-shear and tension-shear specimens are designed to achieve complex stress states. Through a combination of test and parallel finite element simulation, stress–strain curves of the material under various stress states were obtained. Additionally, mechanical property tests were conducted on specimens under typical stress states (uniaxial compression, uniaxial tension, and shear) at a wide range of strain rates and temperatures. To describe the plastic mechanical behavior of materials, a new plastic constitutive model considering temperature, strain rate, and stress state is proposed. Then the model was embedded into the ABAQUS/Explicit finite element software through the VUMAT user material subroutine for numerical simulation. The performance of the new model was systematically compared and analyzed with that of Johnson-Cook model and Xu et al.’s model. The ability of the prediction of plastic deformation in Taylor impact test was evaluated for different models. The results show that the new constitutive model is suitable for predicting the impact deformation associated with complex strain rates, temperatures, and stress states.

{"title":"Constitutive modelling and validating of annealed copper under various stress states, strain rates and temperatures","authors":"Yutian Du , Zejian Xu , Hongzhi Hu , Mengyu Su , Ang Hu , Fenglei Huang","doi":"10.1016/j.ijsolstr.2025.113312","DOIUrl":"10.1016/j.ijsolstr.2025.113312","url":null,"abstract":"<div><div>Metallic materials and structures are often subjected to a wide range of strain, strain rate, temperature and stress state during the engineering application. In order to study the plastic and deformation characteristics of metallic materials under complex stress states, it is necessary to use a constitutive model that considers the effects of stress states. Based on shear specimens suitable for hydraulic Instron testing machines and Hopkinson bar systems (SHPB and SHTB), the compression-shear and tension-shear specimens are designed to achieve complex stress states. Through a combination of test and parallel finite element simulation, stress–strain curves of the material under various stress states were obtained. Additionally, mechanical property tests were conducted on specimens under typical stress states (uniaxial compression, uniaxial tension, and shear) at a wide range of strain rates and temperatures. To describe the plastic mechanical behavior of materials, a new plastic constitutive model considering temperature, strain rate, and stress state is proposed. Then the model was embedded into the ABAQUS/Explicit finite element software through the VUMAT user material subroutine for numerical simulation. The performance of the new model was systematically compared and analyzed with that of Johnson-Cook model and Xu et al.’s model. The ability of the prediction of plastic deformation in Taylor impact test was evaluated for different models. The results show that the new constitutive model is suitable for predicting the impact deformation associated with complex strain rates, temperatures, and stress states.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113312"},"PeriodicalIF":3.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Measurement and calculation method for circumferential plastic strain ratio of anisotropic aluminum alloy tubes

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-22 DOI: 10.1016/j.ijsolstr.2025.113311

Xiao-Lei Cui , Qianxi Sun , Yichun Wang , Shijian Yuan

To improve the finite element analysis (FEA) accuracy of forming hollow tubular components, it is urgent to determine the circumferential mechanical properties of thin-walled tube blanks, especially the plastic strain ratio r_θ, and further investigate their anisotropic deformation and hardening behaviors. In this paper, a new segment-type ring expansion test (SRET) method was established for directly measuring r_θ based on digital image correlation (DIC). It was shown by theoretical analysis that an approximately uniaxial and uniform stress state can be generated when the number of segments is 12 and the initial width-to-diameter ratio of the specimen is about 0.10. It was experimentally proved that the relative error of the measured r_θ of 304 stainless steel welded tube was less than 1 % compared with the r-value of the original 304 sheet. Then, the r_θ of aluminum alloy (6061) tubes was obtained by the SRET method, and the biaxial tensile deformation of the tubes was realized by a controllable biaxial tension test. It is shown that the axial and circumferential plastic strain ratios were 0.460 and 0.638, respectively. The strain path of equal-biaxial stress deviated from the equal-biaxial strain path, and the strain paths of σ_z / σ_θ = 0.75 and 1.333 (reciprocal) were asymmetrically distributed along the equal-biaxial strain line. These results indicate the tubes’ apparent anisotropic deformation behaviors. Finally, the effect of r_θ and yield criterion on predicting the anisotropic hardening behavior was analyzed using the effective stress–strain curve. The results illustrate that r_θ must be considered, and the Balart89 yield criterion with higher order has higher accuracy compared with the Hill48 yield criterion. This research is significant for improving and evaluating the prediction accuracy of plastic constitutive models.

{"title":"Measurement and calculation method for circumferential plastic strain ratio of anisotropic aluminum alloy tubes","authors":"Xiao-Lei Cui , Qianxi Sun , Yichun Wang , Shijian Yuan","doi":"10.1016/j.ijsolstr.2025.113311","DOIUrl":"10.1016/j.ijsolstr.2025.113311","url":null,"abstract":"<div><div>To improve the finite element analysis (FEA) accuracy of forming hollow tubular components, it is urgent to determine the circumferential mechanical properties of thin-walled tube blanks, especially the plastic strain ratio <em>r<sub>θ</sub></em>, and further investigate their anisotropic deformation and hardening behaviors. In this paper, a new segment-type ring expansion test (SRET) method was established for directly measuring <em>r<sub>θ</sub></em> based on digital image correlation (DIC). It was shown by theoretical analysis that an approximately uniaxial and uniform stress state can be generated when the number of segments is 12 and the initial width-to-diameter ratio of the specimen is about 0.10. It was experimentally proved that the relative error of the measured <em>r<sub>θ</sub></em> of 304 stainless steel welded tube was less than 1 % compared with the <em>r</em>-value of the original 304 sheet. Then, the <em>r<sub>θ</sub></em> of aluminum alloy (6061) tubes was obtained by the SRET method, and the biaxial tensile deformation of the tubes was realized by a controllable biaxial tension test. It is shown that the axial and circumferential plastic strain ratios were 0.460 and 0.638, respectively. The strain path of equal-biaxial stress deviated from the equal-biaxial strain path, and the strain paths of <em>σ<sub>z</sub></em> / <em>σ<sub>θ</sub></em> = 0.75 and 1.333 (reciprocal) were asymmetrically distributed along the equal-biaxial strain line. These results indicate the tubes’ apparent anisotropic deformation behaviors. Finally, the effect of <em>r<sub>θ</sub></em> and yield criterion on predicting the anisotropic hardening behavior was analyzed using the effective stress–strain curve. The results illustrate that <em>r<sub>θ</sub></em> must be considered, and the Balart89 yield criterion with higher order has higher accuracy compared with the Hill48 yield criterion. This research is significant for improving and evaluating the prediction accuracy of plastic constitutive models.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113311"},"PeriodicalIF":3.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Ductile damage analysis under extreme low-cycle biaxial shear loadings: Experiments and simulations

IF 3.4 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-02-21 DOI: 10.1016/j.ijsolstr.2025.113292

Zhichao Wei , Marleen Harting , Steffen Gerke , Michael Brünig

This paper addresses the experimental and numerical analysis of ductile damage under extremely low-cycle loading conditions with a large strain range. Shear cyclic loading stress states with stress triaxiality of approximately zero are generated using the biaxially loaded cruciform X0-specimen, with equal positive and negative forces applied to different loading axes. Monotonic and various symmetric cyclic loading patterns are designed to investigate the influence of loading histories on the material response at both macro- and micro-levels. The numerical calculations are performed using a novel anisotropic continuum damage model. For plasticity, the hydrostatic sensitivity Drucker–Prager yield condition with combined hardening is used to characterize the isotropic plastic behavior. Additionally, an anisotropic damage strain tensor that considers stress state influences is used to predict the occurrence and development of damage. Digital image correlation (DIC) technique and scanning electron microscopy (SEM) technique enable comparison of experimental and numerical results in different aspects. The numerical results for load–displacement curves, total strain field, and damage strains agree well with the experimental data, as confirmed by quantitative error analysis in load–displacement curves and statistical analysis of SEM images.

{"title":"Ductile damage analysis under extreme low-cycle biaxial shear loadings: Experiments and simulations","authors":"Zhichao Wei , Marleen Harting , Steffen Gerke , Michael Brünig","doi":"10.1016/j.ijsolstr.2025.113292","DOIUrl":"10.1016/j.ijsolstr.2025.113292","url":null,"abstract":"<div><div>This paper addresses the experimental and numerical analysis of ductile damage under extremely low-cycle loading conditions with a large strain range. Shear cyclic loading stress states with stress triaxiality of approximately zero are generated using the biaxially loaded cruciform X0-specimen, with equal positive and negative forces applied to different loading axes. Monotonic and various symmetric cyclic loading patterns are designed to investigate the influence of loading histories on the material response at both macro- and micro-levels. The numerical calculations are performed using a novel anisotropic continuum damage model. For plasticity, the hydrostatic sensitivity Drucker–Prager yield condition with combined hardening is used to characterize the isotropic plastic behavior. Additionally, an anisotropic damage strain tensor that considers stress state influences is used to predict the occurrence and development of damage. Digital image correlation (DIC) technique and scanning electron microscopy (SEM) technique enable comparison of experimental and numerical results in different aspects. The numerical results for load–displacement curves, total strain field, and damage strains agree well with the experimental data, as confirmed by quantitative error analysis in load–displacement curves and statistical analysis of SEM images.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"313 ","pages":"Article 113292"},"PeriodicalIF":3.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0