Influence of changes of the bending plane position on the fatigue life

Abstract

The paper concerns influence of changes of the bending plane position on the fatigue life. The obtained results were analyzed and compared with the fatigue results for oscillatory bending.The applied specimens were smooth, they had round sections, and they were made of the leaded brass CuZn40Pb2 (MO58). The results obtained under cyclic bending with the plane position change were compared with the results obtained for the specimens with the same parameters under pure oscillatory bending. A change of the bending plane position occurred every 10% fatigue life determined under pure oscillatory bending at the given amplitude of the bending moment, according to the defined fatigue characteristics. Calculated values of nominal stress in a cross section were recalculated according with cyclic material properties and values of elastoplastic stress were obtained.

Strain characteristics of non-ferrous metals obtained on the basic of different loads

“…This applies both to the description of these results for individual tests, and the cumulative characteristic determined for all tests. The last characteristic used is the one proposed by the Authors of this study in form of (9). Another, fourth parameter to be determined appears in this characteristic.…”

“…It should be emphasised here that in the case of bending, these characteristics are most often developed using the model of a perfectly elastic body. This paper compares the characteristics of tensioncompression and oscillatory bending for the model of a perfectly elastic and elasto-plastic body, using the models of strain characteristics [7][8][9]. The analysis has been performed on the basis of fatigue tests completed for the 6082-T6 and 2017(A)-T4 aluminium alloys in the two considered loading states.…”

Low Cycle Fatigue of Steel in Strain Controled Cyclic Bending

“…For stress curves some comparison might be found in (Manson and Muralidharan, 1987;Troschenko, 1996, Megahed 1990). While in (Krzyżak et al, 2014) authors prove that changes in bending plane has an effect on fatigue strength relative to the constant surface bending (pendulum bending). Results from these comparisons show that on the level of fatigue limit the loading method does not affect fatigue life.…”

“…The two other models lack this flaw. What is more, author's proposal (8) is shaped like a letter 'S' which is sometimes advised for stress-life models . In addition, Fig.…”

The Influence of the Strain and Stress Gradient in Determining Strain Fatigue Characteristics for Oscillatory Bending

“…Few studies have paid attention to differences in fatigue resulting from the load [3][4][5][6][7][8][9][10][11][12]. A different fatigue life may correspond, as a result, to the same strain or stress curve.…”