VM316

VM316
J-integral for a Middle-Crack Tension Specimen Under Elastic-Plastic Deformation

Overview

Reference: Anderson, T. L. (2005). The EPRI J-estimation procedure. Fracture Mechanics: Fundamentals and Applications (3rd ed., pp. 398-444). CRC press.
Analysis Type(s): Static Analysis (ANTYPE = 0)
Element Type(s):

2D 8-Node Structural Solid (PLANE183)

Input Listing:

vm316.dat

VM316 requires a supplemental .cdb input file which is too long to include full input listings. This file must be downloaded and placed in your working directory for the test case to run properly. Additionally, the geometry and mesh should be regenerated.

Download link: MAPDL Test Case Files for 2024 R2

vm316-1.cdb

vm316-2.cdb

Test Case

The problem analyzes a rectangular plate with a center crack subjected to uniform tension loading. The load causes elastic-plastic deformation in the model. Two analyses are performed, one with plane stress and the other with plane strain conditions. The J-integral result in each case is compared with the corresponding reference result based on the EPRI J-estimation method.

Figure 575: Model Geometry and Boundary Conditions

Model Geometry and Boundary Conditions

Figure 576: Mesh

Mesh

Material Properties Geometric PropertiesLoading

Young's modulus:

E = 200 GPa

Poisson's ratio:

ν = 0.3

Ramberg-Osgood parameters:

σ0 = 400 MPa
α = 1
n = 10

Crack size:

a = 10 mm

Width:

W = 40 mm

Height:

H = 200 mm

Traction: p = P/(2W)

where P = 22500 N/mm is total force load on full specimen

Analysis Assumptions and Modeling Notes

The problem is analyzed using 2D mesh based on PLANE183. Only one quarter of the plate is modeled due to symmetry. The symmetry boundary conditions are applied to the uncracked ligament (along y = 0) and to the vertical symmetry line (along x = –a). A uniform tensile traction is applied to the top edge of the plate using the SF command. A multilinear isotropic hardening (MISO) plasticity model is used to approximate the equivalent Ramberg-Osgood material model. The J-integral for the crack tip node is computed using CINT commands. The reference result based on the EPRI J-estimation is evaluated as follows.

(316–1)

The elastic part is equal to elastic energy release rate G and is calculated as:

(316–2)

The plastic part is calculated using the tabulated data published by EPRI (tables 9A.10 and 9A.11 in the reference).

Results Comparison

J Target Mechanical APDL Ratio
J (plane stress)23.7625.280.94
J (plane strain)14.6415.570.94