Soil Behavior: Dynamic Soil-Structure Interactions - Dynamic Behavior of Concrete and Seismic Engineering - page 129

Figure 4.2. Cyclic strain-stress curve
When cyclic loading is not closed, the behavior becomes more complicated to
describe. An example of this is given in Figure 4.3. Up to b, the path followed is
identical to the one in Figure 4.2 (first loading curve then discharge curve). At point
b, where V b < V a , the loading sign gets inverted again; the path followed is given by
curve bc, then possibly by cH c if the loading changes its sign again in c. Yet if the
loading is continued beyond c, the path is represented by ca, then beyond c it
follows the first loading curve anew.