PSI - Issue 2_A

Robert Płatek et al. / Procedia Structural Integrity 2 (2016) 285 – 292 Author name / Structural Integrity Procedia 00 (2016) 000–000

289

5

Table 1. Material properties of matrix and particle. Material

Young’s Modulus [MPa]

Poisson’s Ratio [-]

Matrix (epoxy resin) Particle (fused silica)

1200

0.37 0.17

70000

Maximal Principal Stress (MaxPS) was chosen for Fracture Initiation Criterion and the value that cause the failure was set to 60 [MPa]. Adhesion was taken into account during the simulation. Properties that have been assumed during the simulation are presented in Table below:

Table 2. Critical strain release rate and calculated K eff and T ult . G C [mJ/mm2] K eff [mJ/mm2]

T ult [MPa]

0.001

1600000

40

The values K eff and T ult have been calculated using the following equations:

2

G

K

C



(5)

eff

2

ratio  



fail

fail C ult T G  2 

(6)

where: G C – critical strain release rate T ult – nominal stress at damage initiation K eff – effective stiffness

δ ratio – constant. If the value is unknown δ ratio = 0.5 δ fail – the value dependent of the mesh density.

, where l cz – average element size in cohesion

fail  0.05 

l 

cz

connection. The following boundary conditions have been assumed and are presented in Fig. 3.

Fig. 3. Boundary conditions.

4.3. Results As the results the stress-strain curves, stress distribution and crack initiation locations have been obtained. Selected results are shown below. Stress-stress curve is presented in Fig. 4.