2006 Fiscal Year Final Research Report Summary
FORMULATION OF CONSTITUTIVE EQUATION OF FRICTION BASED ON CONCEPT OF SUBLADING SURFACE
| Project/Area Number |
17560446
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Geotechnical engineering
|
|---|
| Research Institution | KYUSHU UNIVERCITY |
|---|
Principal Investigator |
HASHIGUCHI Koichi Kyushu University, Faculty of Agriculture, Special Guest Professor, 大学院農学研究院, 学術特任教員 (10038250)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TSUTSUMI Seiitiro Kyushu University, Faculty of Engineering, Assistant Professor, 大学院工学研究院, 助手 (70344702)
OZAKI Singo Tokyo University of Science, Dept.Mech.Eng, Assistant Professor, 工学部, 助手 (20408727)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Keywords | Friction / Static friction / Kinetic friction / Time-dependence / Subloading surface / Elastoplasticity / Viscoplasticity / Hardening / softening |
|---|
| Research Abstract |
Description of the friction phenomenon as a constitutive equation has been attained first as a rigid-plasticity. Further, it has been extended to an elastoplasticity However, the interior of the sliding-yield surface has been assumed to be an elastic domain and thus the plastic-sliding velocity due to the rate of traction inside the sliding-yield surface is not described. Therefore, the accumulation of plastic-sliding due to the cyclic loading of contact traction cannot be described by these models. On the other hand, the first author of the present article has proposed the subloading surface model which is capable of describing the plastic strain rate by the rate of stress inside the yield surface. Further, the authors proposed the subloading-friction model which describes the smooth transition from the elastic-to plastic-sliding state by incorporating the concept of subloading surface.
It is widely known that when bodies at rest begin to slide to each other, a high friction coefficient appears first, which is called the static-friction, and then it decreases approaching a stationary value, called the kinetic-friction. Further, it has been found that if the sliding ceases for a while and then it starts again, the friction coefficient recovers and the identical behavior as that in the initial sliding is reproduced.
In this research, the subloading-friction model was extended so as to describe the decrease of friction coefficient from the static-to kinetic-friction by the isotropic softening due to the plastic-sliding and the recovery of friction coefficient by the isotropic hardening due to the creep deformations of surface asperities under the contact pressure. The qualitative property of the present model is examined by numerical experiments and the validity for prediction of friction behavior of real materials is verified comparing with test data for the linear sliding phenomenon.
|
