Environmental Engineering Reference
In-Depth Information
they are translated to forces in every joining
material of the macroporous.
5. every contact is checked one by one in order to
break those that have exceeded the maximum
allowable force by the failure diagrams, (n, Q, pair
of values that produces the reach of the Tresca
criterion in the tablet joining material) obtained in
the FeM calculus. The contacts that had broken
are removed from the macroporous by deleting its
contribution to the stiffness matrix [F].
By increasing the load progressively further
displacements and inner forces are calculated to
check how many contacts had broken. in addition,
the position (dip and dip direction) of the broken
contacts are measured.
This process is repeated until the macroporous
cannot reach the equilibrium with the external
load. When this situation happens it is said that
the collapsed of the macroporous material had
taken place.
q
collapse surface
B
p
A
Figure 7. example of the trajectory of tensions during
a collapse calculi.
4
FiRsT ResUlTs
The model is actually in an early stage of
development and needs some improvements. But
the first results obtained with this methodology
are promising. For example, without having
reached the collapse, we have been able to observe
the following:
1. in the early steps of loading (point a in
Figure 7
), the first contacts to break had been
the ones with a low dip angle independently
Figure 8. contour plot of concentration of poles that
has broken on the advanced steps of loading.
of the dip direction. That is to say, the more
vertical contacts are the firsts to break as can be
seen in Figure 6.
2. But when the load is progressively increased
(deviatoric), from point a to point B, as can be
seen in Figure 7, new contacts broke. These new
ones are not horizontal but near to 45º of dip
angle instead. This can be seen in Figure 8.
it is thought that in more advanced steps of
loading; the concentration of poles among 45º
of dip angle will generalize in every dip direction,
leading to the collapsed of the macroporous.
5
conclUsions
in this research, the first steps on how to model
the collapse of a macroporous material had been
shown. The model is in an early stage of develop-
ment and this article is only trying to enounce one of
the possible ways to model this kind of fragile break.
Figure 6. contour plot of concentration of poles that
has broken on the early steps of loading.
