Free torsional vibration of cracked nanobeams incorporating surface energy effects

作     者：R. NAZEMNEZHAD P. FAHIMI R. NAZEMNEZHAD P. FAHIMI

作者机构：School of Engineering Damghan University Damghan 36716-41167 Iran School of Mechanical Engineering Iran University of Science and Technology Tehran 16846-13114 Iran School of Mechanical Engineering College of Engineering University of Tehran Tehran 14399-57131 Iran 

出 版 物：《Applied Mathematics and Mechanics(English Edition)》 (应用数学和力学（英文版）)

年 卷 期：2017年第38卷第2期

页      面：217-230页

核心收录：

学科分类：08[工学] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

主　　题：torsional vibration cracked nanobeam surface energy 

摘      要：This paper investigates surface energy effects, including the surface shear modulus, the surface stress, and the surface density, on the free torsional vibration of nanobeams with a circumferential crack and various boundary conditions. To formulate the problem, the surface elasticity theory is used. The cracked nanobeam is modeled by dividing it into two parts connected by a torsional linear spring in which its stiffness is related to the crack severity. Governing equations and corresponding boundary conditions are derived with the aid of Hamilton＇s principle. Then, natural frequencies are obtained analytically, and the influence of the crack severity and position, the surface energy, the boundary conditions, the mode number, and the dimensions of nanobeam on the free torsional vibration of nanobeams is studied in detail. Results of the present study reveal that the surface energy has completely different effects on the free torsionl vibration of cracked nanobeams compared with its effects on the free transverse vibration of cracked nanobeams.