Page 427 - Biaxial Multiaxial Fatigue and Fracture

Cyclic Behaviour of a Duplex Stainless Steel Under Multiaxial Loading: Experiments and Modelling 41 1

Table 3. Constitutive equations of model NP1.

Strain decomposition
Hooke law ge = &g
- --
Yield function f(a,R,X)=J (o-X)-R-k
= = 2==

Table 4. Constitutive equations of model NP2.

Strain decomposition
- E=$ +gP
-
Hooke law E' = A:g
- --
Yield function f(a,R,X)=J (0-eR-k
= = 2==
Flow rule

Kinematic hardening rule = X=cX. and &=$iip-yiq(p)pzi with i = 1,2,3
=1
I
cp(P) = cp, + (1
C, and C, are constants whereas
C3 = I(A)(CAs-C3)fi with I(A) = (@,-o,)A + 0,
+ C, (A" ( 1 -A) + A( 1 -A)")
= q,A + I-A
2 k:x)z
A=l-cos'a and COS a-

Isotropic hardening rule R = bl(Ql - R)fi
Material parameters E, V, G, k, CI, YI, C2, YZ, ~ 3 ~ (~m, ,0x9 Ox CO, C-3 Cx, n, Ilx, bl, QI
0
9