VM-WB-MECH-099

VM-WB-MECH-099
Mode I Crack Growth Analysis of DCB Using Interface Delamination

Overview

Reference:	Krueger, R. (2012). Application of benchmark examples to assess the single and mixed-mode static delamination propagation capabilities in ANSYS (Report No. NASA/CR-2012-217588).
Solver(s):	Ansys Mechanical
Analysis Type(s):	Static Structural
Element Type(s):	2-D Structural Elements

Test Case

A double cantilever beam is fixed at one end and contains a crack of length a₀ at the other end. Equal and opposite displacements are applied to top and bottom vertices to cause crack growth.

Critical load and corresponding displacement values for Mode I failure are computed using the VCCT method of interface delamination and compared against results shown in Figure 14 of the reference material.

Figure 131: Problem Schematic

Material Properties	Geometric Properties	Loading
T300/1076 Unidirectional Graphite/Epoxy Prepreg E₁₁ = 139 GPa E₂₂ = 10.16 GPa E₃₃ = 10.16 GPa = 0.3 = 0.3 = 0.436 G_Ic = 0.170 kJ/m² G_IIc = 0.494 kJ/m² n (material constant) = 1.62	B = 25 mm 2h = 3 mm 2L = 150 mm a₀ = 20 mm	d = 1.96 mm

Material Properties

Geometric Properties

T300/1076 Unidirectional Graphite/Epoxy Prepreg

E₁₁ = 139 GPa

E₂₂ = 10.16 GPa

E₃₃ = 10.16 GPa

= 0.3

= 0.436

G_Ic = 0.170 kJ/m²

G_IIc = 0.494 kJ/m²

n (material constant) = 1.62

B = 25 mm

2h = 3 mm

2L = 150 mm

a₀ = 20 mm

d = 1.96 mm

Analysis Assumptions and Modeling Notes

The problem is solved using 2-D elements with plain strain element behavior. This problem is solved using two methods of VCCT-based interface delamination, node matching, and matched meshing.

Results Comparison

Result	Target	Mechanical	Error (%)
VCCT (G1) Node Matching (mJ/mm²)	0.17	0.17036	0.212
VCCT (G1) Matched Meshing (mJ/mm²)	0.17	0.17036	0.212