We have animated some of our FE calculations as a means of better understanding the mechanical connections in the field of fracture mechanics/damage mechanics.
The films which have been developed are present in mpg-format and can be viewed by clicking the appropriate reference. However it is necessary that a suitable Movieplayer is present in the Webbrowser prior to viewing the film (this can be found under Preferences/Help in all Webbrowsers).
Shown here is a rotationally symmetric unit cell under a uniaxial tensile force. In the centre of the unit cell is a spherical elastic particle which debonds from the surrounding matrix during the loading process. The colours represent the relative amount of plastic deformation (blue: small, red: large amount of plastic deformation). The cylindrical cell is cut open so that one may view the conditions of its interior.Film in MPEG-format (527 K)
Shown here is another rotationally symmetric unit cell under a uniaxial tensile force. As in the previous example, a particle is embedded inside the cell and is bonded to the surrounding matrix. During the process of increasing the load, the particle breaks when a certain (critical) stress has been obtained. As the load continues to rise, the cavity resulting from this break grows. This cell is also cut open so that one may view the conditions of its interior.Film in MPEG-format (806 K)
During a tension test, a zone of damaged material developes. This zone grows with further elongation of the specimen, and when the sample is broken, it extends over the entire sample cross-section. The development of this damaged zone is shown here (red).Film in MPEG-format (527 K)
The film shows the crack growth in an elastic-plastic material due to a vertically applied load. The crack growth is described with the aid of cohesive elements. Represented here is the development of the stress in the vertical direction, whose maximum travels along the path of the crack tip.Film in MPEG-format (1.8 M)
As in the previous film, shown here is the crack growth in a SE(B) sample made of an elastic-plastic material allowing for damage. Due to the applied load, in the area ahead of the crack tip, the material is damaged by the growth and coalescence of cavities. In the case of maximum damage (red area), the corresponding area of the sample failed. The macroscopic crack follows the path of the damaged elements. The calculation was performed using the GTN model.Film in MPEG-format (3.6 M)
The following is a punch test for a cruciform speciman made of sheet metal. The supports can be detected as green cylinders. The spherical penetrating stamp (not visible in the movie) deforms the sheet metal until a spherical crack develops, this can be detected by the red contour. In the second part of the film, the damaged area of the sample is enlarged to show detail.Film in MPEG-format (920 K)
Represented here is the creep deformation in a turbine blade as a function of time. A constant time centrifugal force and a gas temperature of 800° were assumed. The calculation was executed with a material law for visco-plastic behaviour (Chaboche model).Film in MPEG-format (250 K)
A notched tensile specimen deforms under cyclic loading. While during the first load cycle damage (red contour) is not visible, it appears during the second and third load cycle and causes failure of the specimen. The calculation was performed using the GTN-model with isotropic (!) hardening of the matrix material.Film in MPEG-format (250 K)
A textured representative volume element (RVE) loaded by pure shear and biaxial tension. Each element represents a single crystal, the whole RVE assembles a rolled plate of pure magnesium (hcp metal). Shown are deformed shape and contours of constant stress (third invariant of the stress tensor).Film in Quicktime-format (282 MB!)