European Journal of Mechanics A-Solids最新文献

{"title":"A chemomechanical coupling model for diffusion and stress analysis in polymer-based anti-corrosion coatings","authors":"Liangji Ma ,&nbsp;Bo Zhang ,&nbsp;Yin Yao ,&nbsp;Zhilong Peng ,&nbsp;Dawei Li ,&nbsp;Shaohua Chen","doi":"10.1016/j.euromechsol.2025.105603","DOIUrl":"10.1016/j.euromechsol.2025.105603","url":null,"abstract":"<div><div>The phenomenon of chemomechanical coupling significantly impacts the service performance and lifespan of organic anti-corrosion coatings. Due to differences in matrix materials, the chemomechanical coupling mechanism in organic anti-corrosion coatings is different from that in metal-based materials. How to accurately characterize the chemomechanical coupling behavior in organic anti-corrosion coatings has become an important issue. In this work, a new theoretical model of strong chemomechanical coupling is established for polymer-based anti-corrosion coatings, in which the stress-dependent chemical potential gradient is employed as the fundamental driving force for diffusion and the influence of stress on the diffusion coefficient is considered based on the concept of free volume theory. The model is further utilized to examine the distribution and evolution of the chemomechanical coupling field within a polymer-based anti-corrosion coating system under external loading. Compared with the analysis results of existing weak coupling models, it is found that strong chemomechanical coupling significantly affects the diffusion rate of substances, which in turn affects the concentration field and stress field within the coating. In addition, this model can also explain the experimental result that hydrostatic pressure diminishes the diffusion coefficient. The proposed strong coupling model should be significant in precisely analyzing the diffusion process and mechanical properties of materials or structures in chemomechanical coupling environments.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105603"},"PeriodicalIF":4.4,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143373073","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 3D micromechanical model for hyperelastic rubber-like materials and its numerical resolution by the Asymptotic Numerical Method (ANM)","authors":"Ayoub Ouardi ,&nbsp;Abdellah Hamdaoui ,&nbsp;Makrem Arfaoui ,&nbsp;Adnane Boukamel ,&nbsp;Noureddine Damil","doi":"10.1016/j.euromechsol.2025.105594","DOIUrl":"10.1016/j.euromechsol.2025.105594","url":null,"abstract":"<div><div>In this work, a <span><math><mrow><mn>3</mn><mi>D</mi></mrow></math></span> micromechanical model is developed to describe the behavior of macromolecular chains and to reflect the hyperelastic behavior of rubber-like materials. This model generalizes the <span><math><mrow><mn>2</mn><mi>D</mi></mrow></math></span> model recently developed in Ouardi (2023). The behavior law is defined by the minimization of a potential energy, each macromolecular chain has been represented by elastic segments linked by nonlinear elastic spiral nodes. We thus obtain a model with only three characteristic parameters. We investigate, in the <span><math><mrow><mn>3</mn><mi>D</mi></mrow></math></span> case, the effect of the number of macro-chain segments and the shape of the Representative Volume Element (RVE) using a high-order algorithm of the family of the Asymptotic Numerical Method (ANM) (Cochelin, 2007). In the ANM algorithm, the solution of the nonlinear problem is sought branch by branch, each branch being represented by a Taylor series. In this way, this high-order algorithm makes it easier to continuously investigate the solution curves. Numerical simulations are presented on different RVEs, four and eight chains models (Arruda and Boyce, 1993), under three types of boundary conditions: uniaxial tension, pure shear and equibiaxial tension. These numerical simulations are compared with experimental data from Treloar (1944) to identify the parameters material and to demonstrate the robustness of the proposed model. The studied chains models show a slight influence of the number of macro-chains and the number of segments in the RVE.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105594"},"PeriodicalIF":4.4,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395526","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":"Experimental and micromechanical investigation of precipitate size effects on the creep behaviour of a high chromium martensitic steel","authors":"Jun-Dong Yin ,&nbsp;Lei Wang ,&nbsp;Bao-Yin Zhu ,&nbsp;Xiao Jin ,&nbsp;Chen-Feng Li ,&nbsp;Esteban P. Busso ,&nbsp;Dong-Feng Li","doi":"10.1016/j.euromechsol.2025.105591","DOIUrl":"10.1016/j.euromechsol.2025.105591","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This work involves a mechanistic investigation of the high temperature behaviour of a commercial high-Cr martensitic steel (P91), focussing particularly on the size effects of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;M&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;C&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; carbides. To that purpose, a combination of microstructural observations, experimental measurements and crystal plasticity-based investigations of representative polycrystal aggregates of the steel microstructure are carried out. The tempered martensitic steel was found to exhibit a complex microstructure with hierarchical arrangements, including packets (10–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;50&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), blocks (2–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) and laths (0.2–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), and dispersed nanoscale MX-like precipitates and M&lt;sub&gt;23&lt;/sub&gt;C&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; carbides. The effects of the tempering treatment duration on both the creep behaviour of the steel at 600 °C and the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;M&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;C&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; carbide size were experimentally characterised. The results revealed that the size of the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;M&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mtext&gt;C&lt;/mtext&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; carbides increases with tempering time, resulting in a degradation of the material’s creep resistance.&lt;/div&gt;&lt;div&gt;A novel multi-scale micromechanics-based modelling framework is proposed to describe the measured phenomena. It relies on representative microstructural models of the martensitic steel digitally reconstructed from EBSD measurements, and on a rate-dependent crystal plasticity formulation to describe the inelastic behaviour of the individual martensitic blocks. The latter also incorporates the effects of precipitate size into the internal slip system variable, viz. the slip resistance, through a strengthening term that is inversely proportional to the mean carbide diameter. The crystal plasticity formulation has been implemented numerically into the finite element method and calibrated from data obtained in this work. It is shown that predictions of the polycrystalline aggregate creep response are consistent with the experimental data for a relatively wide range of stress levels and temperatures. Furthermore, the predicted strong effect of carbide size on the steady state creep rate is analysed further to interpret its role on the typically observed scatter on the martensitic steel’s creep data in the 600 to 650 °C temperature range. Finally, the predicted equivalent ine","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105591"},"PeriodicalIF":4.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376435","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":"Investigation on structural design and grounding characteristics of two dimensional double-U honeycomb non-pneumatic tires","authors":"Liguo Zang ,&nbsp;Xinlei Peng ,&nbsp;Jing Sun ,&nbsp;Song Cui ,&nbsp;Yuxing Bai","doi":"10.1016/j.euromechsol.2025.105599","DOIUrl":"10.1016/j.euromechsol.2025.105599","url":null,"abstract":"<div><div>Non-pneumatic tires (NPTs) are subjected to cyclic tension-compression loads during rolling. To address the issues of poor auxetic characteristics and short service life in traditional NPTs, this paper proposes a two dimensional double-U honeycomb (2D DUH) NPT with negative Poisson's ratio (NPR) support structure. Firstly, the support structure for NPT is designed based on the NPR structure of two dimensional double-U unit cells. Then, two typical tire grounding conditions, bottom grounding and top grounding of U-shaped unit cells, are selected according to the structure of the NPT's support part and the grounding characteristics of the tire is investigated. Finally, the influences of height ratio and density of 2D DUH unit cells on tire grounding characteristics are investigated. The results show that the support structure of the grounding part of the 2D DUH NPT has a tendency to shrink inward when compressed by the radial load, increasing the radial stiffness. In addition, the lower ground stress of 2D DUH NPTs increases their service life. The support structure composed of low height ratio and high unit cell density can effectively improve the load-bearing performance and driving stability of 2D DUH NPTs. The results provide a theoretical basis and reference for the structural design of NPTs.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105599"},"PeriodicalIF":4.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143271103","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":"Hysteresis characteristics of entangled porous metallic pseudo-rubber under complex topological structures and thermomechanical coupling effects","authors":"Qinwei Wang ,&nbsp;Zhiying Ren ,&nbsp;Linwei Shi ,&nbsp;Zihao Huang ,&nbsp;Shaotong Feng ,&nbsp;Shuaijun Li","doi":"10.1016/j.euromechsol.2025.105597","DOIUrl":"10.1016/j.euromechsol.2025.105597","url":null,"abstract":"<div><div>Entangled porous metallic pseudo-rubber (EPMPR) is formed by interlaced helical metal wires, and its unique structure can convert mechanical vibration energy into heat, providing significant damping effects. This study innovatively proposes a method for constructing the elastic hysteresis curve of EDMMR at the physical level, and decomposes and extracts the hysteresis curve using virtual manufacturing technology (VMT). Based on finite element numerical calculation nodes, this study constructs the stiffness curve of EPMPR's series-parallel structure, and considers the contact behavior of EPMPR, especially under high-temperature conditions, through dynamic evolution analysis of discretized numerical models of spatial contact behavior, further studying its damping hysteresis behavior. Specifically, this study also proposes for the first time and comprehensively analyzes the dynamic and static parameters of EPMPR under different temperatures and loads, providing in-depth insights into its mechanical behavior and energy dissipation mechanisms. Experimental results demonstrate that under the complex topology structure and thermomechanical coupling, the elastic hysteresis curve of EPMPR can accurately predict its damping characteristics under different high-temperature environments, providing a theoretical foundation for EPMPR's application in advanced equipment and structural extreme environments.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105597"},"PeriodicalIF":4.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376433","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":"On the inadequacy of a stepped-beam approach in predicting shear stresses in tapered slender solids","authors":"Giovanni Migliaccio ,&nbsp;Francesco D’Annibale","doi":"10.1016/j.euromechsol.2025.105590","DOIUrl":"10.1016/j.euromechsol.2025.105590","url":null,"abstract":"<div><div>The stress state in slender elastic cylinders with a straight axis and tapered cross-sections is investigated. Compared to the de Saint-Venant’s cylinder, the continuous variation in the dimensions of the cross-sections along the cylinder’s axis results in additional, non-trivial shear stress distributions within the cross-sections. This paper analytically investigates the dependence of these stresses on taper, a topic of significant practical interest for the design of tapered structural elements commonly employed in various engineering applications, such as components of wind turbines, aircraft, and bridges. The analytical study in this paper is based on a set of partial differential equations and boundary conditions, derived in a recent work, that govern the stress state in three-dimensional tapered cylinders undergoing cross-sectional warping, in- and out-of-plane. A new analytical solution is derived for rectangular cross-sectioned tapered cylinders, resembling the shear webs of large wind turbine blades, with external loads applied at the ends. By examining this paradigmatic case, the inadequacy of approaches based on stepped-beam models in predicting shear stresses in tapered slender solids is demonstrated analytically. Numerical examples, including comparisons to results from the literature and benchmark solutions based on finite element methods, are also provided and corroborate the analytical findings of this study.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"111 ","pages":"Article 105590"},"PeriodicalIF":4.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136062","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":"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}