A Kind Of Infinitesimal Deformation Elastic-plastic Model For Metallic Material Under Uniaxial Cyclic Loading Implementation

A major concern in metallic material under the cyclic loading is unexpected fatigue failures. Constututive relationship is a math ralationship which research the relationship between stress and strain. Because the change about stress and strain is nonlinear, the equation's establishment and studies is the practical application aspect has many difficulties, such as lots of parameter, the difficult determine and complex numerical calculation and so on. At present, studies in this modellings centrate in five kinds of models.Regarding the new models are few.The constitutive in the paper relationship which is used in the single axle cyclic loading simulation is no response.It is a big new spot.Therefore the main things in the present paper apply this kind of model in uniaxial cyclic loading about the metallic material.The main elements included in this article are as follows:(1):Firstly I has analyzed the difference between the cyclic loading and the single loading theoretically,and some experimental results which many scholars do.From these results, we forecast some possible results about metallic materials under uniaxial cyclic loading.Besides some mechanics knowledge about constitutive equation and the cyclic loading.These theories are used for the next several chapters.(2):This modelling used in the present paper is one kind of small distortion Lagrange elastic-plastic constitutive relation.Based on the Ilyushin suppostion, it has defined the plastic strain with the back stress.The result obtained the back stress increasement rule from the Ilyushin supposition.From this it has caused the Ilyushin suppositon the same as flow rule.And it is proved that is is able to describe the complex elastic-plastic characters.Besides it has analyzed this constitutive equation in the descripton metallic material under single axle load process theoretically.(3):This chapter has determined unkonw expression form and some parameters in above constitutive equation.I use the math method and the trial-correct error method.Besides I has carried on under the strain control single axle cyclic loading process to the 316L strainless steel.