J Resistance Curve Estimation of Inhomogeneous CT Specimen

2002 ◽  
Author(s):  
Kiminobu Hojo ◽  
Kazutoshi Ohoto ◽  
Itaru Muroya
Keyword(s):  
Fracture Toughness ◽  
Plane Strain ◽  
Stress Condition ◽  
Estimation Method ◽  
Fe Analysis ◽  
Fracture Toughness Test ◽  
Plane Stress Condition ◽  
Element Analysis ◽  
Curve Estimation ◽  
The Finite Element Analysis

In order to obtain the fracture toughness curve of inhomogeneous CT specimens, a simplified J-R curve estimation method has been proposed. To verify the applicability of this method, the fracture toughness test and the finite element analysis has been conducted. In overmatching case (mismatch ratio M = 2.2), the conventional ASTM standard’s J-R curve exceeded the J-R curve from the FE analysis in the plane strain condition by over 20%. On the other hand, the simplified J-R curve was located between J-R curves from the FE analyses in plane strain and plane stress condition. In undermatching case (M = 0.5), experimental J-R curves with and without the inhomogeneity effect were almost same and the conventional standard is applicable.

Sandwich Beam in Four-Point Bending Test: Experiment and Numerical Models

2014 ◽  
Vol 969 ◽  
pp. 316-319 ◽  
Author(s):  
Stanislav Piovár ◽  
Eva Kormaníková
Keyword(s):  
Stress Condition ◽  
Numerical Models ◽  
Sandwich Beam ◽  
Bending Test ◽  
Plane Stress Condition ◽  
Element Analysis ◽  
The Core ◽  
Four Point Bending ◽  
The Finite Element Analysis ◽  
Four Point Bending Test

The numerical modeling of lightweight sandwich beam in four-point bending, using combination of finite elements by help of two modeling approaches 2-D and 3-D models is presented. The mechanical results of hot-dipped zinc steel face layers and polyurethane foam core, obtained from comprehensive material testing program, were used as input data in order to implement the finite element analysis by the commercial ANSYS code. The material nonlinearities, most pronounced in the core, as well as geometric nonlinearities are included in the models. As was shown an advantage of plane stress condition can be applied in numerical models in one-way bending.

Limit Plastic Collapse on Remaining Ligament of Flawed Welds for ECA Application

2014 ◽  
Author(s):  
Antonio Carlucci ◽  
Kamel Mcirdi
Keyword(s):  
Fracture Toughness ◽  
Brittle Fracture ◽  
Mechanical Strain ◽  
Plastic Collapse ◽  
Fracture Toughness Test ◽  
Element Analysis ◽  
Critical Fracture ◽  
Failure Assessment ◽  
The One ◽  
Girth Welds

Engineering Critical Assessments (ECAs) are routinely used to provide defect acceptance criteria for pipelines girth welds. The Failure Assessment Diagram (FAD) concept is the most widely used methodology for elastic-plastic fracture mechanics analysis of structural components and adopted by standards/documents including BS7910 [1], API579-1/ASME FFS-1 [2], R6 [3]. It is defined by two criterion Kr and Lr which describe the interaction between brittle fracture and fully ductile rupture: Kr measures the proximity to brittle fracture whereas Lr reflects the closeness to plastic collapse. The BS7910 FAD level 2B is the most employed for assessment of flaws under mechanical strain lower than 0.4%, the FAD associated is material-specific and it based on single toughness value obtained from CTOD test, the latter-on gives no information about the tearing initiation. The objective of this paper is to propose an approach for determination of the critical fracture toughness (associated to zero-tearing: JΔa=0). This approach is based on the comparison between the load-CMOD curve provided from a fracture toughness test to the one obtained by Finite Element Analysis (FEA). The goals is to propose a conservative guidance on how to identify a remote strain level below which it may be considered guaranteed the integrity of the remaining ligament.

Plastic-Factor for the Fracture Toughness Test of the SA508Cl.1a Narrow-Gap Welding Part

2007 ◽  
Vol 353-358 ◽  
pp. 146-149
Author(s):  
Yong Huh ◽  
Sung Keun Cho ◽  
Hyung Ick Kim ◽  
Chang Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Nuclear Power ◽  
Piping System ◽  
Fracture Toughness Test ◽  
Narrow Gap ◽  
Narrow Gap Welding ◽  
Element Analysis ◽  
Testing Method ◽  
Toughness Test ◽  
Welding Part

In this study, the plastic η -factors of the SA508Cl.1a narrow-gap welding part, which is used for the primary piping system in a nuclear power plant were obtained by using finite element analysis and the modified fracture toughness testing method was suggested for the narrow-gap welding part. Also, we have performed the fracture toughness test for the SA508Cl.1a narrow-gap welding part by applying the new testing method and then we compared the results with those from the ASTM fracture toughness test.

An analytic procedure for determination of fracture toughness of paper materials

2012 ◽  
Vol 27 (2) ◽  
pp. 352-360 ◽  
Author(s):  
Petri Mäkelä ◽  
Christer Fellers
Keyword(s):  
Fracture Toughness ◽  
Closed Form ◽  
Test Data ◽  
Material Model ◽  
Fracture Toughness Test ◽  
Element Analysis ◽  
Analytic Procedure ◽  
Analytic Expressions ◽  
Commercial Paper

Abstract The aim of the present work was to develop an analytic procedure for determination of the fracture toughness of paper materials based on laboratory material test data. Isotropic deformation theory of plasticity was used to model the tensile material behaviour of six different commercial paper grades. Closed-form analytic expressions for calibrating the material model based on tensile test data were developed. The analytically calibrated material model was shown to predict the non-linear tensile stress-strain behaviour of the investigated paper grades excellently. A closed-form analytic expression for determination of fracture toughness was developed based on the used material model and J-integral theory. The fracture toughness of the investigated paper grades was determined analytically based on laboratory fracture toughness test data. The suggested analytic procedure for determination of the fracture toughness was shown to be in excellent agreement with determinations of fracture toughness based on finite element analysis.

scholarly journals Reproducibility of pop-in using heterogeneous welded joint specimen and cohesive surface model

2019 ◽  
Vol 300 ◽  
pp. 19004
Author(s):  
Sohei Kanna ◽  
Yoichi Yamashita ◽  
Tomoya Kawabata
Keyword(s):  
Fracture Toughness ◽  
Welded Joint ◽  
Surface Model ◽  
Fracture Toughness Test ◽  
Temperature Dependency ◽  
Brittle Crack ◽  
Element Analysis ◽  
Weld Metals ◽  
Cohesive Surface ◽  
Point Bend

When a pop-in as a phenomenon of initiation, propagation, and arrest of a brittle crack occurs in the fracture toughness test, the fracture toughness may be evaluated extremely low. In order to identify the cause of pop-in occurrence, an objective of this study was to demonstrate pop-ins in the three-point bend fracture toughness tests. It was possible to reproduce pop-ins at LBZ zone by preparing the specimens containing heterogeneous weld metals and considering the temperature dependency of the toughness in each welding material. Furthermore, the pop-in occurrence could be simulated by finite element analysis using a cohesive surface.

Sign in / Sign up

Export Citation Format

Share Document