15300

1493 دكتري

دكتري

سازه

اصفهان : دانشگاه صنعتي اصفهان

1398

[دوازده]، [196]ص. : مصور، جدول، نمودار

بيژن برومند

نيما نورمحمدي

محمد مهدي سعادت پور، مجتبي ازهري، فرشيد مسيبي برزي

1398/08/25

كتابنامه

مهندسي عمران

مهندسي عمران

1398/09/03

2577128

The Use of Numerical Methods in Solution of Static and Dynamic Problems Defined by Eringen s Nonlocal Integral Model and Introduction of a Novel Method in Crack Propagation Modeling Reza Abdollahi reza abdollahi@cv iut ac ir Date of Submission October 16 2019 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree Ph D Language FarsiSupervisor Bijan Boroomand Prof boromand@cc iut ac ir Advisor Nima Noormohammadi Assist Prof Department Graduate Program Coordinator Farhad Behnamfar Assoc Prof AbstractWhen the size of the material is at the nanoscale their properties such as color strength andmechanical properties change drastically Among the properties of these materials the studyof their mechanical behavior falls within the field of structural engineering In order to studythe behavior of materials it is needed to gain some knowledge about the governing theory sofirst of all a few non local continuum theories proposed in the field of nanomaterialmechanics are presented here In these theories the set of atoms together with the set ofempty spaces in between them is considered as a continuous matter and after somesimplifications the non local effects are only attributed to the stress strain constitutiverelation Among these theories Eringen s integral theory is chosen as the governing model fornanomaterials After presenting the theories the methods so far developed to solve boundary value problemsin this field are discussed A common and noteworthy point in the existing solution methodsis the fact that they are computationally expensive which can be attributed to the existence ofintegrals in the constitutive relation Therefore reducing the computational cost can be ofparticular importance In an attempt to achieve this goal first in this thesis a variety of newnumerical methods are presented Afterwards by presenting the accuracy and computationalcost of each method the efficiency of the methods is examined in different static anddynamic examples The application of nonlocal theories is not limited to nanostructures and in fact anotheradvantage of using nonlocal theories is the elimination of singular stresses at the crack tip This issue has been investigated using the developed numerical methods through which thesmoothness of the stress distribution around the crack tip has been demonstrated Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 Iran

بيژن برومند

نيما نورمحمدي

محمد مهدي سعادت پور، مجتبي ازهري، فرشيد مسيبي برزي