Dynamic Behavior of Concrete: Constitutive Models - Dynamic Behavior of Concrete and Seismic Engineering - page 79

- F D and F F vary with accumulated visco-plastic work;

V V [2.42]

F , Wk , 0 F , W 0 k W W

D p F p p p

where W p = viscoplastic work, W p * = energy dissipated at time t*', t* = time when
F F is reached, and where k controls energy dissipation and represents the
deterioration of threshold surface;

2.6.2.4. Han and Chen

- Reference: [HAN 85].

- Principle: non-associated plasticity;.

- Application field: high pressure.

- Can model: elasto-plastic phase, strain hardening.

- Cannot model: damage.

- Model data: 4-parameter failure surface (Ottosen, Hsieh-Ting-Chen), and 5-
parameter elastic threshold surface (Willam-Warnke).

Figure 2.17. Elastic threshold surface and failure surface of
the Han and Chen model (from [HAN 85])

The shape of the failure surface is different from the shape of the elasticity initial
surface. As is the case with Ottosen, the equation of the loading surface is:

f r r 0 [2.43]

f