Stable crack growth in fracture mechanics specimens, i.e. side-grooved compact tension C(T), side-grooved middle tension M(T) and side-grooved part-through surface tension PS(T) specimens, is experimentally performed and numerically analysed by finite element calculations using the node shift node release technique. The crack propagation is either controlled by J-resistance curves for the C(T) and M(T) specimens, which are modelled two-dimensionally assuming plane strain conditions, or by local CMOD-resistance curves for the PS(T) specimen, which is modelled three-dimensionally. The triaxiality, i.e. the ratio of the hydrostatic part of the stress tensor to its deviatoric part, is introduced as the quantity characterizing the stress state at the crack tip. For all specimens, the relation between the triaxiality and the slope of the J-resistance curves is shown and analysed, indicating that a decreasing triaxiality results in an increasing slope for the global J-resistance curves concerning the C(T) and M(T) specimens as well as for the local J-resistance curves regarding the PS(T) specimen.