Publikacje

Abstract:

The analysis of the ductile failure evolution in front of the crack is based on the assumption that this process starts when the critical effective plastic strain is reached. In turn, the critical strain at the
onset of the crack growth depends on the stress triaxiality factor and Lode parameter. Thus, in the first step of the analysis a careful calibration of the stress-strain curves is performed, using the modified Bai-
Wierzbicki methodology. It takes into account the evolution of the stress triaxiality and Lode factor during the loading history and the material softening due to the void growth and coalescence. Next, using
five specimen geometries, three materials and three different temperatures the experimental program was carried out and the finite elements analyses were performed using ABAQUS program. The critical
effective plastic strain surfaces were determined in the space: critical strain-triaxiality parameter-Lode factor, and using these surfaces the analysis of the ductile failure processes is performed. The theoretical
analysis is verified by experimental tests. SEN(B) specimens were loaded and the loading was interrupted at the presumed onset of the crack growth. After the tests the scanning microscope observations were
made to analyze the evolution of voids in front of the crack.

B I B L I O G R A F I A[1] Bai, Y., Wierzbicki, T., A new model of metal plasticity and fracture with pressure and Lode dependence, International Journal
of Plasticity, 24 (2008), pp. 1071–1096,
[2] Neimitz A., Gałkiewicz J., Dzioba I., Calibration of constitutive equations under conditions of large strains and stress triaxiality.
Archives of Civil and Mechanical Engineering, 18, 2018, pp. 1123-1135.
[3] Rice, J.R., Tracey, D.M., „On the ductile enlargement of voids in triaxial stress fields”, Journal of the Mechanics and Physics of
Solids, Tom 17, str. 201-217 (1969).

POWRÓT

Strona główna > Publikacje

The Analysis of Ductile Failure Evolution in Front of the Crack Extended abstract