Plane Stress State Conditions Research Articles

Dependence of strain hardening under linear and plane stress-state conditions on austenitic steel structural parameters

1. The analytical expression obtained for values of yield point with repeated straining taking account of a reduction in structural defect density due to partial annihilation of dislocations having an opposite sign due to changes in loading direction is applicable to austenitic structural steels. 2. It was established that repeated strain curves in the range ɛi2p = 0.2-5% do not depend on loading method, and this makes it possible to evaluate steel resistance to repeated plastic deformation beyond the yield point under plane stress conditions from the data of changes in structural defect density with uniaxial tension.

Material cyclic creep and endurance with simple and complex loading under plane stress state conditions

Material cyclic creep and endurance with simple and complex loading under plane stress state conditions

Determination of the fatigue strength of composite materials under plane stress state conditions

Determination of the fatigue strength of composite materials under plane stress state conditions

Determination of the fatigue strength of materials under plane stress state conditions

Determination of the fatigue strength of materials under plane stress state conditions

592. High frequency apparatus for investigation of fatigue of sheet materials in conditions of plane stressed state and elevated temperatures

592. High frequency apparatus for investigation of fatigue of sheet materials in conditions of plane stressed state and elevated temperatures

Twinning in iron at low temperatures under plane stress state conditions

1. Statistical distribution of twin orientations was determined on coarsely granular (dav=1.7 mm) iron tube specimens subjected to five forms of loading in a plane stress state at subzero temperatures. In general the grouping of twin orientations corresponded to the theoretically predicted oreintation of traces produced by planes of the action of the maximum shear stress intersecting the specimen surface. The only exception were the results of tests on specimens strained in nonuniform biaxial tension (K=+0.667). The results as a whole prove that macroscopic shear stresses play a decisive part in the nucleation and growth of twins in polycrystals. 2. The deformation due to twinning constituted a negligible part of the total deformation of specimens at rupture and was not markedly dependent on temperature or stress state conditions. It appears that, regardless of temperature and stress state (in the ranges of those parameters studies), the process of twinning starts and ends in a narrow stress range. 3. The position of the sites of microcrack nucleation and the differences in the way in which twins and microcracks depend on temperature and stress state conditions made it possible to conclude that twins cannot be regarded as the main cause of the nucleation of cleavage in coarsely crystalline iron at temperatures ranging from +20 to −175°C. 4. No evidence of any substantial dependence of the twin density on stress state conditions was observed at any of the test temperatures use. Since the formation of a twin depends on a certain critical stress τcr being reached, it may be concluded that the spherical tensor in the range investigated (τcr 5.16 ⋄ σ0⋄ τσ/0.75) has no significant influence on the twinning phenomena; at the same time it plays an important part in the opening of microcracks formed as a result of plastic deformation of iron.