Please use this identifier to cite or link to this item:
|Title:||Cleavage fracture modeling of pressure vessels under transient thermo-mechanical loading||Authors:||Qian, X.
Dodds Jr., R.H.
Crack front constraint
Middle tension (M(T)) specimen
Modified boundary layer model
Reactor pressure vessels (RPVs)
|Issue Date:||Sep-2008||Citation:||Qian, X., Dodds Jr., R.H., Yin, S., Bass, R. (2008-09). Cleavage fracture modeling of pressure vessels under transient thermo-mechanical loading. Engineering Fracture Mechanics 75 (14) : 4167-4189. ScholarBank@NUS Repository. https://doi.org/10.1016/j.engfracmech.2008.03.011||Abstract:||The next generation of fracture assessment procedures for nuclear reactor pressure vessels (RPVs) will combine non-linear analyses of crack front response with stochastic treatments of crack size, shape, orientation, location, material properties and thermal-pressure transients. The projected computational demands needed to support stochastic approaches with detailed 3-D, non-linear stress analyses of vessels containing defects appear well beyond current and near-term capabilities. In the interim, 2-D models become appealing to approximate certain classes of critical flaws in RPVs, and have computational demands within reach for stochastic frameworks. The present work focuses on the capability of 2-D models to provide values for the Weibull stress fracture parameter with accuracy comparable to those from very detailed 3-D models. Weibull stress approaches provide one route to connect non-linear vessel response with fracture toughness values measured using small laboratory specimens. The embedded axial flaw located in the RPV wall near the cladding-vessel interface emerges from current linear-elastic, stochastic investigations as a critical contributor to the conditional probability of initiation. Three different types of 2-D models reflecting this configuration are subjected to a thermal-pressure transient characteristic of a critical pressurized thermal shock event. The plane-strain, 2-D models include: the modified boundary layer (MBL) model, the middle tension (M(T)) model, and the 2-D RPV model. The 2-D MBL model provides a high quality estimate for the Weibull stress but only in crack front regions with a positive T-stress. For crack front locations with low constraint (T-stress < 0), the M(T) specimen provides very accurate Weibull stress values but only for pressure load acting alone on the RPV. For RPVs under a combined thermal-pressure transient, Weibull stresses computed from the 2-D RPV model demonstrate close agreement with those computed from the corresponding crack front locations in the 3-D RPV model having large negative T-stresses. Applications of this family of 2-D models provide Weibull stress values in excellent agreement with very detailed 3-D models while retaining practical levels of computational effort. © 2008 Elsevier Ltd. All rights reserved.||Source Title:||Engineering Fracture Mechanics||URI:||http://scholarbank.nus.edu.sg/handle/10635/65302||ISSN:||00137944||DOI:||10.1016/j.engfracmech.2008.03.011|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Jun 12, 2019
WEB OF SCIENCETM
checked on Jun 12, 2019
checked on May 24, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.