VM255

VM255
Delamination Analysis using Contact Based Debonding Capability

Overview

Reference:

G. Alfano and M. A. Crisfield, Finite Element Interface Models for the Delamination Analysis of Laminated Composites: Mechanical and Computational Issues, International Journal for Numerical Methods in Engineering, Vol. 50, pp. 1701-1736 (2001).

Analysis Type(s):

Static analysis (ANTYPE = 0)

Element Type(s):

2D 4-Node Structural Solid Element (PLANE182)

2D 3-Node Surface-to-Surface Contact Element (CONTA172)

2D Target Segment Element (TARGE169)

Input Listing:

vm255.dat

Test Case

A double cantilever beam of length l, width w and height h with an initial crack of length a at the free end is subjected to a maximum vertical displacement U_max at top and bottom free end nodes. Determine the vertical reaction at point P based on the vertical displacement using contact based debonding capability.

Figure 434: Double Cantilever Beam Sketch

Material Properties

Geometric Properties

Composite

E₁₁ = 135.3 GPa

E₂₂ = 9.0 GPa

E₃₃ = 9.0 GPa

G₁₂ = 5.2 GPa

ν₁₂ = 0.24

ν₁₃ = 0.24

ν₂₃ = 0.46

Interface

C1 = 1.7 MPa

C2 = 0.28 N/mm

C5 = 1.0E-5

L = 100 mm

a = 30 mm

h = 3 mm

w = 20 mm

U_max= 10 mm

Analysis Assumptions and Modeling Notes

A double cantilever beam has been analyzed under displacement control using 2D plane strain formulation with a regular mesh of 4 x 200 4-node PLANE182 elements. An imposed displacement of Uy = 10 mm acts at the top and bottom free nodes. The interface is modeled with contact elements with a bonded contact option and a cohesive zone material model.

Bilinear material behavior with linear softening characterized by maximum traction and critical energy release rate (TBOPT = CBDE) cohesive zone material option is used with maximum traction t_o = 1.7 MPa and critical energy rate G_c= 0.28 N/mm. Debonding is often characterized by convergence difficulties during material softening. To overcome this problem artificial damping parameter of 1.0e-8 is used.

Based on the interface material parameters used, results obtained using Mechanical APDL should be compared to the results shown in Figure 15(a) in the reference.

Results Comparison

	Target	Mechanical APDL	Ratio
Max RFORCE and corresponding DISP using debonding:
RFORCE FY (N)	50.00	50.663	1.013
DISP UY(mm)	1.50	1.50	1.000
RFORCE and corresponding DISP U = 10.0 using debonding:
RFORCE FY (N)	24.00	24.862	1.036
DISP UY(mm)	10.00	10.00	1.00