### Abstract

applications.

Original language | English |
---|---|

Pages (from-to) | 365-366 |

Number of pages | 2 |

Journal | Proceedings in Applied Mathematics and Mechanics, PAMM |

Volume | 14 |

Issue number | 1 |

Early online date | 21 Mar 2014 |

DOIs | |

Publication status | Published - Dec 2014 |

Event | 85th Annual Meeting of the International Association of Applied Mathematics and Mechanics, GAMM 2014 - Erlangen-Nürnberg, Germany Duration: 10 Mar 2014 → 14 Mar 2014 |

### Fingerprint

### Keywords

- cyclic analysis
- design limits
- fatigue assessment
- creep-fatigue strength

### Cite this

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**Cyclic yield strength in definition of design limits for fatigue and creep.** / Gorash, Yevgen; Mackenzie, Donald.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Cyclic yield strength in definition of design limits for fatigue and creep

AU - Gorash, Yevgen

AU - Mackenzie, Donald

PY - 2014/12

Y1 - 2014/12

N2 - This study proposes a cyclic yield strength (CYS, σc ) as a key characteristic for the definition of safe design for engineering structures operating under fatigue and creep conditions. CYS is defined on a cyclic stress-strain curve, while monotonic yield strength (MYS, σm ) is defined on a monotonic stress-strain curve. Both values of σc and σm are identified using a 2-steps fitting procedure of the experimental stress-strain curves using Ramberg-Osgood and Chaboche material models. Comparison of σc and fatigue endurance limit σf on the S-N fatigue curve reveals that they are approximately equal. Hence, basically safe fatigue design is guaranteed in purely elastic domain defined by the σc . A typical creep rupture curve in time-to-failure approach for creep analysis has 2 inflections corresponding to the σc and σm . These stresses separate 3 sections on the creep rupture curve, which are characterised by 3 different creep fracture modes and 3 creep deformation mechanisms. Thus, basically safe creep design is guaranteed in linear creep domain with brittle failure mode defined by the σc . These assumptions are confirmed for several structural low- and high-alloy steels for normal and high-temperature applications.

AB - This study proposes a cyclic yield strength (CYS, σc ) as a key characteristic for the definition of safe design for engineering structures operating under fatigue and creep conditions. CYS is defined on a cyclic stress-strain curve, while monotonic yield strength (MYS, σm ) is defined on a monotonic stress-strain curve. Both values of σc and σm are identified using a 2-steps fitting procedure of the experimental stress-strain curves using Ramberg-Osgood and Chaboche material models. Comparison of σc and fatigue endurance limit σf on the S-N fatigue curve reveals that they are approximately equal. Hence, basically safe fatigue design is guaranteed in purely elastic domain defined by the σc . A typical creep rupture curve in time-to-failure approach for creep analysis has 2 inflections corresponding to the σc and σm . These stresses separate 3 sections on the creep rupture curve, which are characterised by 3 different creep fracture modes and 3 creep deformation mechanisms. Thus, basically safe creep design is guaranteed in linear creep domain with brittle failure mode defined by the σc . These assumptions are confirmed for several structural low- and high-alloy steels for normal and high-temperature applications.

KW - cyclic analysis

KW - design limits

KW - fatigue assessment

KW - creep-fatigue strength

UR - http://onlinelibrary.wiley.com/doi/10.1002/pamm.201410170/pdf

U2 - 10.1002/pamm.201410170

DO - 10.1002/pamm.201410170

M3 - Article

VL - 14

SP - 365

EP - 366

JO - Proceedings in Applied Mathematics and Mechanics, PAMM

JF - Proceedings in Applied Mathematics and Mechanics, PAMM

SN - 1617-7061

IS - 1

ER -