Creep damage and crack initiation in P92–BNi2 brazed joint

Jiang, Wenchun; Zhang, Weiya; Zhang, Guodong; Luo, Yun; Zhang, Y.C.; Woo, Wanchuck; Tu, S.T.

doi:10.1016/j.matdes.2015.01.011

Cited by 17 publications

(2 citation statements)

References 28 publications

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“…The E and yield stress, S y , of the material at 600°C are 134 GPa and 300 MPa, respectively. At 650°C, the values of E = 125 GPa and S y = 180 MPa (extracted from Jiang et al 17 ) are employed. The plastic deformation (true stress-strain curve) at temperatures of 600°C and 650°C obeys the power law isotropic work hardening and is given by:…”

Section: Constitutive Materials and Damage Modelsmentioning

confidence: 99%

Evaluation of Monkman–Grant strain as a key parameter in ductility exhaustion damage model to predict creep rupture of grade 92 steel

Alang

Zhao

Nikbin

2021

The Journal of Strain Analysis for Engineering Design

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Conventional strain-based numerical prediction assumes that failure occurs when ductility is exhausted or accumulation of creep strain reaches the critical failure strain. Due to instability at the onset of rupture, the failure strain value appears to be scattered and leads to the erroneousness in prediction. In this paper, a new local constraint-based damage model incorporating the Monkman–Grant ductility, as a measure of strain during uniform creep deformation stage, was implemented into a Finite Element (FE) model to predict the creep damage and rupture of Grade 92 steel under uniaxial and multiaxial stress states. The prediction was applied on plain and notched bar specimens with various notch acuities. The uniaxial stress-dependent Monkman–Grant (MG) failure strain was adopted in the FE to simulate the influence of the constraints which were induced by the creep damage. The implication of reduced failure strain in long-term creep time on the rupture prediction is discussed. The multiaxial MG failure strain of the notched bar, which has a lower value than uniaxial failure strain due to the geometrical constraint, was estimated based on the linear inverse relationship between normalised MG failure strain and normalised triaxiality factor. It was found that the results obtained from the proposed technique were in good agreement with the experimental data within the scatter band of ± factor of 2. It was shown that MG failure strain can be used as an alternative to strain at fracture. MG strain outweighed strain at fracture because the determination of its value only required short-term testing to be performed. In most cases considered in the present investigation, the rupture-type fracture was predicted, however, there was evidence that under high constraint and low stress, stable crack propagation occurred before fracture. The location of the maximum creep damage was found to be dependent on the creep time, geometry or acuity level of the specimen. For sharp notch specimen, the failure was initiated near the notch root, however, as the notch radius increased, the initiation location moved further away towards the specimen centre.

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Section: Constitutive Materials and Damage Modelsmentioning

confidence: 99%

Evaluation of Monkman–Grant strain as a key parameter in ductility exhaustion damage model to predict creep rupture of grade 92 steel

Alang

Zhao

Nikbin

2021

The Journal of Strain Analysis for Engineering Design

View full text Add to dashboard Cite

show abstract

“…A study of notch effect on creep damage taking account of multiaxial stresses is very essential for the creep design of brazed joint, which has been addressed in this paper. Another issue is that residual stress is generated during the brazing and has a great effect on creep [9], which has also been considered in this paper. Wang et al [10] demonstrated that the effects of residual stress on creep crack initiation time are related to the creep ductility and primary load level.…”

Section: Introductionmentioning

confidence: 99%