Does the cyclic J-integral describe the crack-tip opening displacement in the presence of crack closure?

In this paper, the correlation of the cyclic J-integral, Δ J , and the cyclic crack-tip opening displacement, Δ CTOD , is studied in the presence of crack closure to assess the question if Δ J describes the crack-tip opening displacement in this case. To this end, a method is developed to evaluate Δ J numerically within finite-element calculations. The method is validated for an elastic–plastic material that exhibits Masing behavior. Different strain ranges and strain ratios are considered under fully plastic cyclic conditions including crack closure. It is shown that the cyclic J-integral is the parameter to determine the cyclic crack-tip opening displacement even in cases where crack closure is present.