European Journal of Mechanics A-Solids最新文献

{"title":"Extracting mechanical properties and uniaxial stress-strain relation of materials from dual conical indentation by machine learning","authors":"Songjiang Lu","doi":"10.1016/j.euromechsol.2025.105598","DOIUrl":"10.1016/j.euromechsol.2025.105598","url":null,"abstract":"<div><div>Indentation testing is one of the most convenient methods to investigate the mechanical response of materials because of its comparative simplicity in sample preparation and capabilities in testing specimens with small-volumes where tensile experiments are difficult to perform. For indentation problems, it is attractive and meaningful to directly determine the elasto-plastic properties (parameters) or tensile stress-strain relations of materials from indentation responses. In this work, an artificial neural network (ANN) model is combined with finite element (FE) analysis to address this inverse indentation problem. To avoid the non-uniqueness issue, both indentation load-depth curves of two commonly used sharp indenters, namely conical and Berkovich indenters, are employed to inversely identify the material properties. A database generated by FE simulations is used to train the ANN model. The prediction performance of the trained ANN model was validated by testing the model on the simulated and experimental load-depth data. The results indicate that the ANN model can accurately predict the material parameters from only the loading part of indentation load-depth curves. In addition, the relationship between the prediction accuracy and the values of material parameters, the comparison between the prediction performances of ANN models based on single and dual conical indentation, and the effect of data noise on the prediction accuracy of the ANN model, are systematically discussed. The ANN-based method of inverse indentation analysis proposed in this study provides a convenient and effective alternative method for predicting material properties from indentation tests.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105598"},"PeriodicalIF":4.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compliance changes for a fatigue edge crack","authors":"James Vidler ,&nbsp;Andrei Kotousov ,&nbsp;Ching-Tai Ng","doi":"10.1016/j.euromechsol.2025.105592","DOIUrl":"10.1016/j.euromechsol.2025.105592","url":null,"abstract":"<div><div>The evaluation of the compliance of specimens or structures with cracks has a fundamental significance in fatigue and fracture. Compliance-based experimental methods are widely utilised to evaluate crack length, residual stresses, crack tip opening loads and the effective stress intensity factor. These methods are often based on linear elastic solutions and, in the absence of analytical and numerical elasto-plastic solutions for propagating fatigue cracks, are largely reliant on empirical criteria and best practice approaches. This article utilises the simplified strip-yield model to investigate the change in compliance for an edge crack in a semi-infinite plate propagating under constant amplitude cyclic loading under plane stress conditions. The main objective of the work is to develop an analytical model for the influence of crack tip plasticity, crack face contact and plasticity-induced crack closure on compliance changes during the loading and unloading parts of a fatigue cycle. The present modelling results agree well with several highly accurate experimental studies published in the past, and allow the investigation of general tendencies in the compliance changes associated with applied fatigue loading. The latter can be very useful in the analysis of outcomes of experimental studies and development of new compliance-based techniques.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105592"},"PeriodicalIF":4.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation-based fatigue assessment using the 4R method in different load conditions","authors":"Tero Pesonen ,&nbsp;Mariia Kozlova ,&nbsp;Antti Ahola ,&nbsp;Timo Björk ,&nbsp;Masoud Moshtaghi","doi":"10.1016/j.euromechsol.2025.105600","DOIUrl":"10.1016/j.euromechsol.2025.105600","url":null,"abstract":"<div><div>This study examines the use of simulation-based model for the fatigue assessment that combines computational weld mechanics (CWM) and mechanical analysis to obtain local fatigue-effective stresses. The applied CWM analysis includes sequentially coupled heat source modeling and mechanical analysis to predict local material properties, residual stresses, and welding deformations. Subsequentially, fatigue assessments are conducted based on the material cyclic simulations considering different load conditions, welding-induced residual stresses and estimated material condition changes at the heat-affected zone (HAZ). The current work evaluates the fatigue strength of a longitudinal gusset joint subjected to different load conditions: constant amplitude, variable amplitude, and quasi-statically overloaded constant amplitude loads. The computational fatigue assessments are performed using a multiparametric fatigue assessment approach, namely the 4R method, and computational results are verified with the experimental fatigue tests. The simulated welding-induced residual stresses and material properties at the HAZ showed reasonable agreement with the experimental results. In addition, the <em>S</em>–<em>N</em> master curve fitted to the experimental fatigue data and simulation stress results shows a relatively small scatter range index, equal to <em>T</em>_{<em>σ</em>,sim} = 1.25 considering different load conditions. The model sensitivity study to the estimated material properties showed that the cyclic strength coefficient is the most influential factor in fatigue life estimation.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105600"},"PeriodicalIF":4.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of temperature dependent elastic anisotropy on residual stresses and ratcheting in transpiration cooled Nickel gas turbine blades","authors":"Kefan Qiu ,&nbsp;Yang Liu ,&nbsp;Simon Gill ,&nbsp;Christos Skamniotis","doi":"10.1016/j.euromechsol.2025.105595","DOIUrl":"10.1016/j.euromechsol.2025.105595","url":null,"abstract":"<div><div>The conditions required for the ratcheting of a structure due to thermal and load cycling are typically calculated assuming a constant Young's modulus throughout the cycle. We show that this type of incremental collapse occurs at lower cyclic loads when the variation in Young's modulus with temperature is taken into account. This is because the increase of Young's modulus upon unloading from the high temperature operation state to the room temperature shutdown state enhances the residual stress field <span><math><mrow><mi>ρ</mi></mrow></math></span>, and therefore the cyclic variation of stresses. In this respect, we find that Koiter's kinematic shakedown theorem still works as if the material has a room temperature yield stress that decreases as <span><math><mrow><mi>ρ</mi></mrow></math></span> increases. This more broadly implies that conventional shakedown and low cycle fatigue analysis methods which have relied upon the fictitious elastic stress cannot be deemed credible for high temperature problems, since any location of a structure experiences an enhanced cyclic stress variation compatible with the enhancement of <span><math><mrow><mi>ρ</mi></mrow></math></span> with Young's modulus. Our practical example is a double plate unit of a transpiration cooled single crystal Nickel gas turbine blade, whereby the two-fold increase of Young's modulus upon cooldown from <span><math><mrow><mn>1100</mn><mo>°C</mo></mrow></math></span> to <span><math><mrow><mn>20</mn><mo>°C</mo></mrow></math></span> leads to compressive ratcheting at over 30% lower temperature differences than previously predicted. Our work informs the design of clean energy, transport and defence assets suffering severe thermal loads, including fusion/fission reactors, re-useable rockets, cryogenic hydrogen and transpiration cooling systems.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105595"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-monotonic dependence of martensitic transformation on crystal orientation of NiTi shape memory alloy","authors":"Aimeng Zhang ,&nbsp;Shaobin Zhang ,&nbsp;Fa Wu ,&nbsp;Chun Li","doi":"10.1016/j.euromechsol.2025.105593","DOIUrl":"10.1016/j.euromechsol.2025.105593","url":null,"abstract":"<div><div>Crystal orientation is considered a pivotal factor influencing phase transformation of shape memory alloys (SMAs), which has been confirmed by comparing several specific orientations. A comprehensive atomic-scale understanding of the physical mechanisms of the crystal orientation effects could significantly contribute to the development of high-performance SMAs. This study systematically explores the dependence of the transformation behavior of NiTi SMA on the crystal orientation, focusing on preferred martensite variants and their corresponding energy evolutions, utilizing molecular dynamic simulations. The research reveals that crystal orientation plays a crucial role in selecting preferred martensite variants during phase transformation from austenite to martensite phase, and the selection rules can be predicted through a simple theoretical model based on the minimum free energy criterion. This phenomenon leads to a non-monotonic variation in the energy barriers during phase transformation and the mechanical properties, such as transformation stress and energy hysteresis, with the crystal orientation. Furthermore, the study validates the significance of this understanding in developing high-performance bicrystal SMA by constructing crystal grains with different orientations.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105593"},"PeriodicalIF":4.4,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient feature extraction for morphologically complex self-assembled porous microstructures using computational homology and unsupervised machine learning","authors":"Farshid Golnary,&nbsp;Mohsen Asghari","doi":"10.1016/j.euromechsol.2025.105589","DOIUrl":"10.1016/j.euromechsol.2025.105589","url":null,"abstract":"<div><div>Porous microstructures formed during the self-assembly process exhibit complex morphologies that directly influence their material properties. This study proposes an efficient method for microstructural parametrization, specifically designed for these complex structures. The method effectively combines computational homology and unsupervised machine learning techniques to achieve this goal. Computational homology is a technique that analyzes topological spaces by examining \"holes\" of different dimensions. Therefore, it is particularly effective for the morphological analysis of random and heterogeneous porous microstructures. In this regard, computational homology is used to extract simpler disjoint regions within the microstructure. convolutional autoencoder, k-means clustering, and other quantitative analyses are employed to analyze these regions as grayscale images.</div><div>A microstructure may consist of numerous disjoint regions. To efficiently represent these regions in a lower-dimensional space, a convolutional autoencoder is used. K-means clustering is then applied to group the low-dimensional representations of these disjoint regions based on morphological similarity. By clustering the microstructural regions, we can analyze the microstructures more efficiently and interpretably. Each disjoint region belongs to a cluster, and the microstructure is thus represented by low-dimensional features, indicating the percentage of disjoint regions in each cluster. To enhance interpretability, the feature orders are sorted based on their correlation with relative density. The correlation analysis revealed that the proposed microstructural representation features are interpretable, as the majority of features exhibit correlations with material properties such as Young's modulus and Poisson's ratio as well as topological features such as Betti numbers.</div><div>The proposed method is computationally efficient due to its low-dimensional representation of the microstructure and is interpretable, with features sorted and organized based on their correlation with relative density. To demonstrate its efficiency, numerical experiments were performed on microstructures created during the spinodal decomposition process. The results show that the method is effective for computational tasks such as material properties prediction and inverse design.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105589"},"PeriodicalIF":4.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A modification of Holzapfel–Ogden hyperelastic model of myocardium better describing its passive mechanical behavior","authors":"Jiří Vaverka,&nbsp;Jiří Burša","doi":"10.1016/j.euromechsol.2025.105586","DOIUrl":"10.1016/j.euromechsol.2025.105586","url":null,"abstract":"<div><div>The passive mechanical behavior of the myocardium is usually mathematically described within the framework of hyperelasticity. One of the most popular models of this kind is that proposed by Holzapfel and Ogden in 2009. It is an orthotropic model formulated in terms of a reasonably selected set of scalar invariants representing different components of the myocardium. Several modifications of the model have emerged over the years. In this paper, we present another one which is characterized by an innovative approach to the modeling of myocardial “sheets”, i.e. lamellar collagenous structures that endow the myocardium with orthotropic mechanical properties. We describe their contribution by means of a less common scalar invariant which expresses the change of area of an oriented planar element (representing the plane of a sheet). To compare our formulation with the original model, we matched both of them to the biaxial tension and simple shear experimental data from the literature using a nonlinear least-squares optimization algorithm. The objective function for each model included both biaxial and simple shear data in order to obtain a single set of parameters for both deformation modes. The results show that our modified model can accurately describe both types of tests. The total residual is lowered by approximately 80% by our modification and <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> increases from 0.877 to 0.978 which demonstrates the significance of our modification on the quality of the fit.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105586"},"PeriodicalIF":4.4,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free vibration properties of novel sandwich plates with a layered and rotational core","authors":"Youlong Wang ,&nbsp;Yuxiang Cai ,&nbsp;Kamal Hosen ,&nbsp;Junwei Pan","doi":"10.1016/j.euromechsol.2025.105588","DOIUrl":"10.1016/j.euromechsol.2025.105588","url":null,"abstract":"<div><div>The layered sandwich plate structure is widely used in various fields due to its lightweight and high-strength characteristics. To further enhance the functionality of these structures and expand their application areas, this study investigates the impact of an innovative method for adjusting the interlayer angle. This study adopts experimental analysis and numerical simulation methods, taking honeycomb core and grid core as examples, to explore the influence of interlayer angle on the first 9 natural frequencies and vibration modes of bilayer and tri-layer circular sandwich plates, and explain the mechanism of the influence of interlayer angle on the structural natural frequency through theoretical analysis. The results indicate that 1) at different angles, the natural frequencies of the same order vibration modes exhibit significant differences. For instance, in the case of the grid core, the minimum change rate of the natural frequency can exceed 10%, and the maximum can reach 16.68%; 2) compared to the unadjusted layered plates, which exhibit localized deformation in higher-order vibration modes, the stiffness distribution becomes more uniform after rotation, transforming the vibration modes into overall continuous deformations; 3) the proposed method allows for considerable changes in natural frequencies of various orders while maintaining stable structural mechanical properties without adding weight. This effectively avoids resonance with the working environment and promotes uniform stiffness distribution, making the structure suitable for use in more demanding stable environments.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105588"},"PeriodicalIF":4.4,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thermodynamically consistent wear modeling approach based on damage accumulation","authors":"Quentin Caradec ,&nbsp;Matthieu Breuzé ,&nbsp;Claude Stolz ,&nbsp;Habibou Maitournam","doi":"10.1016/j.euromechsol.2025.105583","DOIUrl":"10.1016/j.euromechsol.2025.105583","url":null,"abstract":"<div><div>Due to the diversity of mechanisms involved, wear is very complex to model. Wear models are mostly empirical, and they sometimes fail to accurately predict wear evolution. In this paper, a damage-based wear modeling approach is developed in the framework of continuum thermodynamics. The model is physically consistent and aims at accounting for the progressive accumulation of near-surface degradation leading to material detachment. A thermodynamic driving force associated with wear is derived under the form of an energy release rate. Wear evolution is then driven by the accumulation of near-surface damage, and wear occurs when the surface damage value reaches a threshold. The damage evolution problem is treated using the thick level set approach, providing a non-local formulation for damage evolution. Numerical simulations are conducted on a fretting test case using the finite element method, and the results compared to those obtained with a classical friction energy wear law.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105583"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plane strain problems for flexoelectric semiconductors","authors":"Jinchen Xie ,&nbsp;Xiaowen He","doi":"10.1016/j.euromechsol.2025.105573","DOIUrl":"10.1016/j.euromechsol.2025.105573","url":null,"abstract":"<div><div>The flexoelectric effect, which is induced by strain gradients, is a pervasive phenomenon in dielectric and semiconductor materials. Flexoelectric semiconductors have considerable potential for application in the field of micro- and nanoelectronics, although their theoretical research is still in its infancy. In particular, there is a paucity of research on the exact solutions of the multiphysics field coupling problems for flexoelectric semiconductors. In light of these considerations, this paper presents the first comprehensive and rigorous investigation into the plane strain issues pertaining to flexoelectric semiconductors. The coupled governing equations for flexoelectric semiconductors under plane strain conditions are reformulated for decoupling purposes. On this basis, we derive the exact solutions to a series of plane-strain problems for flexoelectric semiconductors, including bending of beams, deformation of pressurized cylinders, cylindrical cavities, cylindrical inhomogeneities, and cylindrical inclusion problems with eigenstrain. By employing these exact solutions, we investigate the size effect of multiphysics field coupling in flexoelectric semiconductors and the influence of the initial doping concentration. Furthermore, we employ a mixed finite element method for numerical simulations of flexoelectric semiconductors. The high degree of agreement between the finite element solutions and the analytical exact solutions validates the utility of the exact solutions derived in this study as benchmark solutions for related numerical methods. This study offers insights and guidance for the design of flexoelectric semiconductor devices and provides a deeper understanding of the multiphysics field coupling behavior of flexoelectric semiconductors containing defects.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105573"},"PeriodicalIF":4.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}