Acta Mechanica最新文献_第9页

Free vibrational characteristics of various imperfect FG beam via a novel integral Timoshenko’s theory 通过新型积分季莫申科理论分析各种不完全 FG 梁的自由振动特性

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-08-07 DOI: 10.1007/s00707-024-04046-2

Khelifa Lakhdar, Mohamed Sadoun, Farouk Yahia Addou, Fouad Bourada, Abdelmoumen Anis Bousahla, Abdelouahed Tounsi, Khaled Mohamed Khedher, Abdeldjebbar Tounsi

{"title":"Free vibrational characteristics of various imperfect FG beam via a novel integral Timoshenko’s theory","authors":"Khelifa Lakhdar, Mohamed Sadoun, Farouk Yahia Addou, Fouad Bourada, Abdelmoumen Anis Bousahla, Abdelouahed Tounsi, Khaled Mohamed Khedher, Abdeldjebbar Tounsi","doi":"10.1007/s00707-024-04046-2","DOIUrl":"10.1007/s00707-024-04046-2","url":null,"abstract":"<div><p>In the current paper, a new first-order Timoshenko’s theory (N-FSDBT) based on the indefinite integral is proposed to examine the vibrational behavior of power-law (P-FG), sigmoid (S-FG), and exponential (E-FG) functionally graded beams. The developed formulation takes into consideration the effect of the transverse shear deformation. During the manufacturing process, faults, such as the presence of micro voids or porosities in FGMs, structural imperfections may arise in the material. For this purpose, this research has focused on the modification of the mixture rules including the porosity volume fraction. To illustrate the porosity variation throughout the body of the structures, the uniform, nonuniform and mass-density porosity distribution are considered in the present examination. Mathematical approach is used to simplify the FG beam governing equation based on classical beam theory (CBT) and new-FSDBT frame works for free vibration. The resultant equations of motion are solved using the Navier’s technique, for simply supported FG beams. To validate the results, a parameter study was presented to analyze the impact of the types of volume fraction (FG beam-type), the effects of porosity distribution, material exponent parameter, slenderness ratio, and porosity index on the dynamic behavior of imperfect FG beams.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6287 - 6304"},"PeriodicalIF":2.3,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944363","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

Closed-loop active shape control of radial rib in umbrella antenna based on fiber-optic shape sensing 基于光纤形状传感的伞形天线径向肋片闭环主动形状控制

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-08-05 DOI: 10.1007/s00707-024-04033-7

Yuhang Qie, Shujun Tan, Maoqi Wu, Feixiong Gao, Junchao Guo

{"title":"Closed-loop active shape control of radial rib in umbrella antenna based on fiber-optic shape sensing","authors":"Yuhang Qie, Shujun Tan, Maoqi Wu, Feixiong Gao, Junchao Guo","doi":"10.1007/s00707-024-04033-7","DOIUrl":"10.1007/s00707-024-04033-7","url":null,"abstract":"<div><p>Radial ribs are important supporting parts of umbrella antenna, and its shape is a crucial factor affecting the overall reflector accuracy. Considering the difficulty of in-orbit shape sensing, a fiber-optic shape sensing (FOSS) method for the radial rib is presented in this paper, then on the basis of FOSS a shape active control method for the radial rib driven by Macro-Fiber Composite actuators is proposed. Firstly, combining the deformation characteristics of the radial rib structure, an improved Ko displacement algorithm is proposed for its shape sensing using distributed fiber-optic. Then, establish the shape active control model with the Influence-Coefficient-Matrix method, and propose a closed-loop shape active control method with FOSS as feedback for the radial rib. In this paper, the optimization problem of solving control voltage is established by using the Least-Square method, and Root-Mean-Square error is taken as the convergence condition. Finally, numerical simulation and experiment show that the relative error of the shape sensing with fiber-optic is less than 5%, and the shape accuracy of radial rib after control is improved by more than 90% to reach submillimeter level, which verifies the effectiveness of the radial rib shape active control method based on FOSS.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6225 - 6248"},"PeriodicalIF":2.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944411","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

Behavior of a wave with absorption at discontinuity: telegrapher’s equation approach 波在不连续处的吸收行为：电报员方程方法

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-08-05 DOI: 10.1007/s00707-024-04045-3

Marco Nizama, Manuel O. Cáceres

引用次数: 0

Dynamic of an inhomogeneous three-layer sphere under cyclic pressure 非均质三层球体在循环压力下的动态变化

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-08-04 DOI: 10.1007/s00707-024-04041-7

Xi-meng Zhang, Hui Qi

{"title":"Dynamic of an inhomogeneous three-layer sphere under cyclic pressure","authors":"Xi-meng Zhang, Hui Qi","doi":"10.1007/s00707-024-04041-7","DOIUrl":"10.1007/s00707-024-04041-7","url":null,"abstract":"<div><p>In this paper, the dynamic characteristics of inhomogeneous three-layer spheres under spherical wave induced by cyclic pressure are studied. The density is assumed to have a square of inverse proportional function distribution along the radius. Firstly, on the basis of Lamb decomposition and variable separation method, the analytical expression of spherical wave is conducted, which satisfies the stress equilibrium on the outer and inner surfaces of the sphere, and the Euler equation is obtained due to inhomogeneity. Next, algebraic equations with respective boundary conditions are composed and solved by effective truncation techniques. Finally, a comparison and discussion are conducted between the model presented in this article and the homogeneous model obtained by the Legendre polynomial expansion. Obtained results enable to reveal the influence on the dynamic stress concentration factor intensity under proper conditions. The conclusions of this article are verified by comparing the analytical solutions to the ones obtained by finite element method. This paper can provide a theoretical method for the analysis of mechanical properties of inhomogeneous multilayered spherical structure under dynamic loading.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6181 - 6224"},"PeriodicalIF":2.3,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944410","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

Connecting rate-dependent loading and relaxation behaviors of glassy polymers by fractional models 用分数模型连接玻璃态聚合物随速率变化的加载和松弛行为

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-31 DOI: 10.1007/s00707-024-04038-2

Zhouquan Wang, Wei Cai, Changyu Liu, Leixiao Wu

引用次数: 0

Analysis of dynamic anti-plane characteristics of circular laminated structures with bimaterial media 双材料介质圆形层压结构的动态抗平面特性分析

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-31 DOI: 10.1007/s00707-024-04037-3

Linzhan Wang, Jie Yang, Fenghua Cao, Mingliang Yu

引用次数: 0

Modelling and analysis of imperfect and sliding interfaces on Love-type wave in non-planar non-homogeneous nearly incompressible elastic layered structure 非平面非均质近乎不可压缩弹性层状结构中不完美和滑动界面对爱型波的影响建模与分析

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-30 DOI: 10.1007/s00707-024-04040-8

Santan Kumar, Md Hasanuzzaman, Richa Kumari

{"title":"Modelling and analysis of imperfect and sliding interfaces on Love-type wave in non-planar non-homogeneous nearly incompressible elastic layered structure","authors":"Santan Kumar, Md Hasanuzzaman, Richa Kumari","doi":"10.1007/s00707-024-04040-8","DOIUrl":"10.1007/s00707-024-04040-8","url":null,"abstract":"<div><p>This work aims to develop a mathematical model for Love-type wave (LTW) propagation in non-planar non-homogeneous nearly incompressible elastic layered structure with imperfect and sliding interfaces following a geometrical model. Concretely, the geometrical model constitutes two unlike non-homogeneous nearly incompressible elastic materials forming a combination of stratum and substrate, which in turn involve imperfectness at the interface and non-planar boundaries (NPBs). With aid of applicable mathematical techniques, the expressions of displacement components (DCs) of LTW have been determined for both planar boundaries (PBs) and NPBs with imperfect interface. As a special case of the study, the expressions of DCs of LTW have also been deduced for both PBs and NPBs with sliding interface. Further, as an offshoot of the current study, dispersion relations (DRs) of LTW propagating in non-homogeneous and homogeneous nearly incompressible as well as isotropic elastic structures having imperfect, perfect and sliding interfaces have been established and validated with the results present in the literature. For graphical delineation, numerical computation of the DCs and phase velocity (PV) of LTW has been performed. The influences of non-homogeneity parameters, curvature parameters, interfacial parameter and wave number on DCs and PV of LTW have been figured out. It has been revealed that the presence of non-homogeneity in structure has substantial effect on the DCs and PV of LTW. Moreover, a comparative approach has been brought in to study the DCs and PV of LTW in non-homogeneous and homogeneous cases of nearly incompressible elastic structure (NIES) having imperfect and sliding interfaces.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6125 - 6156"},"PeriodicalIF":2.3,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867794","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

Qualitative properties for a Moore–Gibson–Thompson thermoelastic problem with heat radiation 带有热辐射的摩尔-吉布森-汤普森热弹性问题的定性特性

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-30 DOI: 10.1007/s00707-024-04035-5

José R. Fernández, Ramón Quintanilla

引用次数: 0

Static behavior of FG sandwich beams under various boundary conditions using trigonometric series solutions and refined hyperbolic theory 利用三角级数解法和精炼双曲理论分析 FG 夹层梁在各种边界条件下的静态行为

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-30 DOI: 10.1007/s00707-024-04039-1

Farouk Yahia Addou, Abdelhakim Kaci, Abdeldjebbar Tounsi, Abdelmoumen Anis Bousahla, Abdelouahed Tounsi, Mohammed A. Al-Osta, Sherain M. Y. Mohamed, Saad Althobaiti, Mahmoud M. Selim

{"title":"Static behavior of FG sandwich beams under various boundary conditions using trigonometric series solutions and refined hyperbolic theory","authors":"Farouk Yahia Addou, Abdelhakim Kaci, Abdeldjebbar Tounsi, Abdelmoumen Anis Bousahla, Abdelouahed Tounsi, Mohammed A. Al-Osta, Sherain M. Y. Mohamed, Saad Althobaiti, Mahmoud M. Selim","doi":"10.1007/s00707-024-04039-1","DOIUrl":"10.1007/s00707-024-04039-1","url":null,"abstract":"<div><p>A refined hyperbolic shear deformation theory is presented to analyze the mechanical behavior of isotropic and sandwich functionally graded material (FGM) beams under various boundary conditions. The material properties are considered to be isotropic at each point and change across the thickness direction. The volume fraction gradation follows a power law distribution with respect to the FGM core or skins of the beam. The solution is attained by minimizing the total potential energy. This recent theory is a new type of third-order shear deformation theory that includes undetermined integral variables. The recent theory describes the variation of transverse shear strains throughout the thickness of a beam. It shows how these strains satisfy the zero traction boundary conditions on the top and bottom surfaces, all without the need for shear correction factors. An analytical solution based on trigonometric series is developed to solve the problem while satisfying various boundary conditions. Comparative studies are conducted to validate the accuracy and efficiency of this method. The current model can accurately predict the static responses of functionally graded isotropic and sandwich beams with arbitrary boundary conditions.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6103 - 6124"},"PeriodicalIF":2.3,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867793","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

High temperature creep and embrittlement in metals and alloys under conditions of the long-term usage 金属和合金在长期使用条件下的高温蠕变和脆化

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-07-26 DOI: 10.1007/s00707-024-04026-6

Regina Saitova, Alexander Arutyunyan, Holm Altenbach

{"title":"High temperature creep and embrittlement in metals and alloys under conditions of the long-term usage","authors":"Regina Saitova, Alexander Arutyunyan, Holm Altenbach","doi":"10.1007/s00707-024-04026-6","DOIUrl":"10.1007/s00707-024-04026-6","url":null,"abstract":"<div><p>Since the fundamental works of Kachanov and Rabotnov, creep damage mechanics is an established field of research in solid mechanics. The starting point is the creep behavior of materials under moderate loads but elevated temperatures. The final stage of creep behavior is accompanied by damage and other microstructural changes such as embrittlement. In the present paper a detailed analysis of literature is given. A special focus is made on the different types of representation of damage by scalar, vectorial and tensorial variables. In addition, some Russian sources are presented which are not widely known yet. The survey is representative, but not complete - due to the large number of sources, it is not possible to provide a complete overview. Considering the huge number of parameters of tensorial damage variables which should be established experimentally in the second part of the paper a simple model for the high temperature creep and embrittlement in metals and alloys under conditions of the long-term usage is introduced. The model is an extension of R. Arutunyan’s model developed in the 90th of the last century. The extension includes the consideration of a compressible medium, the introduction of the mass conservation law and true stress, and definition of the damage parameter as a relative change in the density of the material. The parameters are experimentally estimated and the comparison of simulations and experiments is given.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"235 10","pages":"6033 - 6055"},"PeriodicalIF":2.3,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782055","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