已为您找到该学者11条结果 成果回收站
【期刊论文】Surface effects on buckling of nanowires under uniaxial compression
王刚锋, Gang-Feng Wang, a) and Xi-Qiao Feng
APPLIED PHYSICS LETTERS 94, 141913(2009),-0001,():
-1年11月30日
Based on the conventional Euler buckling model, uniaxial compression tests have been utilized recently to measure the mechanical properties of nanowires. However, owing to the increasing ratio of surface area to bulk at nanoscale, the influence of surface energy becomes prominent and should be taken into consideration. In this letter, an analytical relation is given for the critical force of axial buckling of a nanowire by accounting for both the effects of surface elasticity and residual surface tension. This study might be helpful to characterize the mechanical properties of nanowires or design nanobeam-based devices in a wide range of applications.
-
40浏览
-
0点赞
-
0收藏
-
0分享
-
135下载
-
0
-
引用
【期刊论文】Surface Effects on the Near-Tip Stresses for Mode-I and Mode-III Cracks
王刚锋, Gang-Feng Wang, Xi-Qiao Feng, Tie-Jun Wang, Wei Gao
JANUARY 2008, Vol.75,-0001,():
-1年11月30日
Based on the surface elasticity theory and using a local asymptotic approach, we analyzed the influences of surface energy on the stress distributions near a blunt crack tip. The dependence relationship of the crack-tip stresses on surface elastic parameters is obtained for both mode-I and mode-III cracks. It is found that when the curvature radius of a crack front decreases to nanometers, surface energy significantly affects the stress intensities near the crack tip. Using a kind of surface elements, we also performed finite element simulations to examine the surface effects on the near-tip stresses. The obtained analytical solution agrees well with the numerical results.
crack, surface elasticity, stress, nanomechanics
-
32浏览
-
0点赞
-
0收藏
-
0分享
-
194下载
-
0
-
引用
王刚锋, Gang-Feng Wanga), Xi-Qiao Feng
APPLIED PHYSICS LETTERS 90, 231904 2007 ,-0001,():
-1年11月30日
Surface effects often play a significant role in the physical properties of micro-and nanosized materials and structures. In this letter, the authors presented a theoretical model directed towards investigation of the effects of both surface elasticity and residual surface tension on the natural frequency of microbeams. A thin surface layer was introduced on the upper and lower surfaces to rationalize the near-surface material properties that are different from the bulk material. An explicit solution is derived for the natural frequency of microbeams with surface effects. This study might be helpful for the design of microbeam-based sensors and some related measurement techniques.
-
63浏览
-
0点赞
-
0收藏
-
0分享
-
96下载
-
0
-
引用
【期刊论文】A piezoelectric constitutive theory with rotation gradient effects
王刚锋, Gang-Feng Wang, Shou-Wen Yu, Xi-Qiao Feng∗
European Journal of Mechanics A/Solids 23(2004)455-466,-0001,():
-1年11月30日
Some recent experiments evidenced that the piezoelectric coefficients of such piezoelectric materials as PZT and BiTiO3 have an evident dependence on the grain size. With respect to the success of strain gradient theories in interpreting size effect phenomena of conventional (non-piezoelectric) solids and the dependence of piezoelectricity on rotation of polar clusters, a new piezoelectric theory with rotation gradient effects is formulated in the present paper to elucidate the size effect problems of piezoelectric solids. The constitutive relations of materials with different symmetries are specialized, and their corresponding independent material constants are discussed. For the typical 6 mm class of piezoelectric crystalline materials, a potential function method is presented for solving plane problems. The analytical solution of a thin piezoelectric film bonded on a rigid substrate illustrates the size-dependent prediction of the present theory.
Piezoelectricity, Constitutive relation, Rotation gradient, Size effect, Couple stress
-
47浏览
-
0点赞
-
0收藏
-
0分享
-
100下载
-
0
-
引用
【期刊论文】The Contact Problem in a Compressible Hyperelastic Material
王刚锋, G.F. Wang, T.J. Wang
JULY 2007, Vol.74,-0001,():
-1年11月30日
We consider the contact problem for a particular class of compressible hyperelastic materials of harmonic type undergoing finite plane deformations. Using complex variable techniques, we derive subsidiary results concerning a half-plane problem corresponding to this class of materials. Using these results, we solve the contact problem for a harmonic material in the case of a uniform load acting on a finite area. Finally, we show how we can then deduce the corresponding results for the case of a point load.
contact problem, finite elastic deformations, harmonic materials
-
46浏览
-
0点赞
-
0收藏
-
0分享
-
50下载
-
0
-
引用