A Finite Element Study on the Integrity Evaluation Method of Subclad Cracks Under Pressurized Thermal Shock Transients

2003 ◽  
Vol 125 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Jin-Su Kim ◽  
Bon-Geol Koo ◽  
Jae-Boong Choi ◽  
Young-Jin Kim ◽  
Yun-Won Park
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Thermal Shock ◽  
Evaluation Method ◽  
Crack Depth ◽  
Parent Material ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Pressurized Thermal Shock

The reactor pressure vessel is usually clad with stainless steel to prevent corrosion and radiation embrittlement, and thus, the population of subclad cracks is higher than that of surface cracks. In fact, a number of subclad cracks have been found during in-service-inspections. These subclad cracks should be assumed for a safe operation under normal conditions and faulted conditions such as pressurized thermal shock (PTS). There are several elastic stress intensity factor (SIF) solutions for subclad cracks which are used for ASME fracture assessment procedures. However, these solutions are known to be overly conservative due to intrinsic assumptions. In this paper, full 3-D elastic-plastic finite element analyses were performed to investigate the validity of the present ASME code in evaluating the integrity of vessel under PTS conditions. The solution in ASME Section XI code gives accurate SIF values when the crack tip is close to cladding. However, the difference between the code solution and elastic plastic finite element analysis (EPFEA) results become significant with increasing crack depth. This difference is caused by the stress discontinuity at the interface between cladding and parent material. Elastic finite element analysis (EFEA) results, which do not consider plastic deformation at the clad material, also showed a big difference compared to those from EPFEA. Therefore, it is recommended to perform EPFEA for the accurate assessment of subclad cracks under PTS which causes plastic deformation at the cladding.

Study on Formation Precision for Metal Wire Bended

2012 ◽  
Vol 157-158 ◽  
pp. 833-838
Author(s):  
Fei Peng Guo ◽  
Bin Yao ◽  
Ke Hong
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Linear Relationship ◽  
Metal Wire ◽  
Rolling Angle ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Forming Angle

In this paper, a finite element analysis is used to predict accurately the elastic-plastic deformation of metal wire in roll-bended process; this method can transform the deflections of required rolling angle into the compensation of the CNC bending wire manufacture. The conclusion shows that the rolling angle keeps a linear relationship with the final forming angle in a certain range. And it has been proved to be correct and precise under certain conditions by the CNC roll-bended manufacture.

Finite element analysis of notched bars subjected to elastic-plastic deformation

2013 ◽  
Vol 10 (1) ◽  
pp. 55-64
Author(s):  
Mathew Tsang ◽  
Sangarapillai Kanapathipillai ◽  
Mahiuddin Chowdhury
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Element Analysis ◽  
Elastic Plastic

Overview of Code Case on Alternative Design Methodology by Using Elastic-Plastic Finite Element Analysis for Class 1 Vessels in the JSME Rules on Design and Construction

2010 ◽  
Author(s):  
Seiji Asada ◽  
Takashi Hirano ◽  
Tetsuya Nagata ◽  
Naoto Kasahara
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Methodology ◽  
Evaluation Method ◽  
Plastic Collapse ◽  
Element Analysis ◽  
Alternative Design ◽  
Elastic Plastic ◽  
Plastic Analysis ◽  
Design And Construction

An alternative design methodology by using elastic-plastic finite element analysis has been developed and published as a code case of the JSME Rules on Design and Construction for Nuclear Power Plants (The First Part: Light Water Reactor Structural Design Standard). This code case applies elastic-plastic analysis to evaluation of such failure modes as plastic collapse, shakedown, thermal ratchet and fatigue. Advantages of this evaluation method are no use of stress linearization/classification, consistent use of Mises equivalent stress and applicability to complex 3-dimentional structures which are hard to be treated by the conventional stress classification method. The evaluation method for plastic collapse consists of the Lower Bound Approach Method, Twice-Elastic-Slope Method and Elastic Compensation Method. Cyclic Yield Area (CYA) criterion based on elastic analysis is applied to screening evaluation of shakedown limit instead of secondary stress evaluation, and elastic-plastic analysis is performed when the CYA screening criterion is not satisfied. Strain concentration factors can be directly calculated based on elastic-plastic analysis.

Transient Thermo-Mechanical Plowing Contact Between Rigid Sphere and Elastic-Plastic Sphere

2012 ◽  
Author(s):  
Wenping Song ◽  
Andrey Ovcharenko ◽  
Longqiu Li ◽  
Guangyu Zhang ◽  
Frank E. Talke
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Contact Zone ◽  
Temperature Rise ◽  
Rigid Sphere ◽  
Mechanical Contact ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Plastic Sphere

Transient thermo-mechanical contact between a rigid sphere sliding over an elastic-plastic sphere with a larger radius is studied using finite element analysis. Plastic deformation and temperature rise in the contact zone between the two spheres are investigated.

Sign in / Sign up

Export Citation Format

Share Document