Applied and Computational Mechanics最新文献_第4页

Natural frequencies analysis of functionally graded circular cylindrical shells 功能梯度圆柱壳的固有频率分析

Applied and Computational Mechanics Pub Date : 2021-10-01 DOI: 10.24132/acm.2021.654

Nabeel Alshabatat, Mohammad Zannon

{"title":"Natural frequencies analysis of functionally graded circular cylindrical shells","authors":"Nabeel Alshabatat, Mohammad Zannon","doi":"10.24132/acm.2021.654","DOIUrl":"https://doi.org/10.24132/acm.2021.654","url":null,"abstract":"In the present work, a study on natural frequencies of functionally graded materials (FGM) circular cylindrical shells is presented. TheFGM is considered to be a mixture of two materials. The volumetric fractions are considered to vary in the radial direction (i.e., through the thickness) in compliance with a conventional power-law distribution. The equivalent material properties are estimated based on the Voigt model. The analysis of the FGM cylindrical shells is performed using the third-order shear deformation shell theory and the principle of virtual displacements. Moreover, the third-order shear deformation shell theory coupled with Carrera’s unified formulation is applied for the derivation of the governing equations associated with the free vibration of circular cylindrical shells. The accuracy of this method is examined by comparing the obtained numerical results with other previously published results. Additionally, parametric studies are performed for FGM cylindrical shells with several boundary conditions in order to show the effect of several design variables on the natural frequencies such as the power-law exponent, the circumferential wave number, the length to radius ratio and the thickness to radius ratio.","PeriodicalId":37801,"journal":{"name":"Applied and Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41540063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A New Solution for the Classical Problem of a Rigid Body Motion in a Liquid 液体中刚体运动经典问题的新解

Applied and Computational Mechanics Pub Date : 2021-10-01 DOI: 10.22055/JACM.2021.38552.3245

H. Yehia, S. Megahid

引用次数: 0

Design of Doubly Salient Permanent Magnet Generator for Output Power Enhancement using Structural Modification 利用结构改进提高输出功率的双凸极永磁发电机的设计

Applied and Computational Mechanics Pub Date : 2021-10-01 DOI: 10.22055/JACM.2021.37952.3131

Pattasad Seangwong, A. Siritaratiwat, W. Sriwannarat, N. Fernando, P. Khunkitti

{"title":"Design of Doubly Salient Permanent Magnet Generator for Output Power Enhancement using Structural Modification","authors":"Pattasad Seangwong, A. Siritaratiwat, W. Sriwannarat, N. Fernando, P. Khunkitti","doi":"10.22055/JACM.2021.37952.3131","DOIUrl":"https://doi.org/10.22055/JACM.2021.37952.3131","url":null,"abstract":"The doubly salient permanent magnet generator (DSPMG) is widely known as an efficient machine for electrical production from renewable energy. In this paper, we aim to improve the output power of the DSPMG using a structural modification, which is targeted for low-speed electrical generations. Structural parameters including the stator pole depth, thickness of permanent magnet, stator pole arc, and number of winding turns were adjusted, then an optimal value of those parameters was selected based on the characteristics of the generator tested during no-load and on-load conditions. Simulations were based on the finite element method. The generator was targeted to be used for the rated power of 200 W. It was found that the optimally designed generator had a higher electromotive force of 36.1%, a lower cogging torque of 20%, and a higher output power of 12.2% than the conventional structure. The leakage flux of the proposed structure was also improved from the conventional one. Thus, the generator designed in this work could be another capable choice for electrical generation from renewable energy. The proposedly modified technique can also be adapted for output profile improvement of the doubly salient permanent magnet machines which are extensively used for renewable energy production nowadays.","PeriodicalId":37801,"journal":{"name":"Applied and Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44371397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Simulation of Hydraulic Fracture Propagation in Fractured Coal Seams with Continuum-discontinuum Elements 裂隙煤层水力裂隙扩展的连续-非连续元模拟

Applied and Computational Mechanics Pub Date : 2021-10-01 DOI: 10.22055/JACM.2021.37475.3022

Hai-chao Zhou, Huixing Gao, C. Feng, Zizheng Sun

引用次数: 2

Size Effect on the Axisymmetric Vibrational Response of Functionally Graded Circular Nano-Plate Based on the Nonlocal Stress-Driven Method 基于非局部应力驱动法的功能梯度圆形纳米板轴对称振动响应的尺寸效应

Applied and Computational Mechanics Pub Date : 2021-09-21 DOI: 10.22055/JACM.2021.38131.3159

M. Shariati, M. Shishesaz, R. Mosalmani, S. A. S. Roknizadeh

{"title":"Size Effect on the Axisymmetric Vibrational Response of Functionally Graded Circular Nano-Plate Based on the Nonlocal Stress-Driven Method","authors":"M. Shariati, M. Shishesaz, R. Mosalmani, S. A. S. Roknizadeh","doi":"10.22055/JACM.2021.38131.3159","DOIUrl":"https://doi.org/10.22055/JACM.2021.38131.3159","url":null,"abstract":"In this work, the axisymmetric-vibrational behavior of a size-dependent circular nano-plate with functionally graded material with different types of boundary conditions was investigated. The analysis was performed based on the Stress-driven model (SDM) and Strain-gradient theory (SGT) in conjunction with classical plate theory. The governing equations of motion and their corresponding equations for boundary conditions were obtained based on Hamilton’s principle and solved using the generalized differential quadrature rule. Results show that this method is applicable to the vibrational analysis of such structures with a fast convergence rate; as N approaches 6 for the first mode, and 10 for the second as well as the third and fourth modes, regardless of the type of boundary condition. In both models, the influences of various parameters such as size-effect parameter Lc, material heterogeneity index n, and types of boundary conditions were obtained on the first four modes and compared with each other. Results indicate that the natural frequencies in these modes increase with an increase in the heterogeneity index n, and size-effect parameter Lc. Additionally, these parameters appear to have a stiffening effect on the nano-plate vibrational behavior. However, for a nano-plate resting on a knife or simply supported edge, in the first mode, the SDM shows a more stiffening effect on the plate behavior as compared with the SGT. Nonetheless, for the clamped and free edge boundary conditions, both models predicted the same behavior. The SGT showed a higher-stiffening effect only in the fourth mode, for all types of considered boundary conditions.","PeriodicalId":37801,"journal":{"name":"Applied and Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42673047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Body of Optimal Parameters in the Weighted Finite Element Method for the Crack Problem 裂纹问题加权有限元法中的最优参数体

Applied and Computational Mechanics Pub Date : 2021-09-15 DOI: 10.22055/JACM.2021.38041.3142

S. Chamran, V. Rukavishnikov

引用次数: 3

Size Effect on Inclined Cracking in Unidirectional Composites 单向复合材料中尺寸对倾斜裂纹的影响

Applied and Computational Mechanics Pub Date : 2021-09-02 DOI: 10.22055/JACM.2020.33481.2234

A. Dönmez

引用次数: 1

Thermo-elastic creep analysis and life assessment of rotating thick pressurized cylindrical shells using third-order shear deformation theory 基于三阶剪切变形理论的旋转厚受压圆柱壳热弹性蠕变分析及寿命评估

Applied and Computational Mechanics Pub Date : 2021-09-01 DOI: 10.22059/JCAMECH.2021.306967.546

T. Taghizadeh, M. Z. Nejad

{"title":"Thermo-elastic creep analysis and life assessment of rotating thick pressurized cylindrical shells using third-order shear deformation theory","authors":"T. Taghizadeh, M. Z. Nejad","doi":"10.22059/JCAMECH.2021.306967.546","DOIUrl":"https://doi.org/10.22059/JCAMECH.2021.306967.546","url":null,"abstract":"In the present study, time-dependent thermo-elastic creep behavior and life assessment of rotating thick-walled cylindrical shells made of 304L austenitic stainless steel (304L SS) are investigated based on the third-order shear deformation theory (TSDT). Loading is composed of a uniform internal pressure, distributed temperature field, and a centrifugal body force due to rotating speed. Norton’s law is utilized as the material creep constitutive model. Using the minimum total potential energy principle, a system of differential equations in terms of displacement and boundary conditions are derived. Then, the governing equations are solved with an analytical approach, which leads to an accurate solution. Subsequently, an iterative procedure is also proposed to determine the stresses and deformations at different creep times. Larson-Miller Parameter (LMP) and Robinson's linear life fraction damage rule are employed for assessing the creep damages and the remaining life of cylindrical shells. To the best of the researcher’s knowledge, in the previous studies, there is no study carried out into third-order shear deformation theory for thermo-elastic creep analysis of cylinders. To validate the accuracy of the suggested method based on TSDT, a comparison among analytical results and those of the finite element method (FEM) is performed and very good agreement is found. The results indicate that the present analysis is accurate and computationally efficient.","PeriodicalId":37801,"journal":{"name":"Applied and Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48097068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

An analytical solution for nonlinear vibration of floating plate on the fluid by modified multiple scales method 流体上浮板非线性振动的修正多尺度法解析解

Applied and Computational Mechanics Pub Date : 2021-09-01 DOI: 10.22059/JCAMECH.2021.327315.639

F. Rabiee, A. Jafari

{"title":"An analytical solution for nonlinear vibration of floating plate on the fluid by modified multiple scales method","authors":"F. Rabiee, A. Jafari","doi":"10.22059/JCAMECH.2021.327315.639","DOIUrl":"https://doi.org/10.22059/JCAMECH.2021.327315.639","url":null,"abstract":"The aim of the present paper is to analytically study the nonlinear forced vibration of a rectangular plate floating on the fluid by Modified Multiple Time Scales method for the first time. It is assumed that the fluid is stationary, incompressible, non-viscous, and non-rotational, and the plate is subjected to transversal excitation. The boundary condition is considered to be simply supported. Using von Karman nonlinear strain displacement relationships, the extended Hamilton principle, and FSTD plate theory, the partial differential equations of motion are derived. The fluid is mathematically modeled by Bernoulli equation and the velocity potential function. Galerkin method is then applied for converting the nonlinear partial differential equations into time-dependent nonlinear ordinary differential equations. The resulted equations are solved analytically by the Modified Multiple Scales Method, thereafter. Despite the large number of derivatives and calculations of the conventional multiple scale method, this approach is very simple and straightforward. The results reveal an excellent agreement with the traditional Multiple Scales method results and existing studies, and are more accurate than other available results. The effect of the presence of fluid near the plate on natural frequency and amplitude of vibration of plate are studied. The effects of some key parameters of the system are also examined.","PeriodicalId":37801,"journal":{"name":"Applied and Computational Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42963224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A review on stress-driven nonlocal elasticity theory 应力驱动的非局部弹性理论综述

Applied and Computational Mechanics Pub Date : 2021-09-01 DOI: 10.22059/JCAMECH.2021.331410.653

M. Shariati, M. Shishesaz, Hossein Sahbafar, Mortaza Pourabdy, M. Hosseini

引用次数: 11