Okay, opening statement:
The very fact that the buildings survived the crash of the planes into the buildings suggests that
a time dependent behavior at the material level affected the structural stability of the structure
to the point of failure. On the other hand, the failure per se reveals the existence of a weakest
link in the structural system, which ultimately failed because of a lack of redundancy.
So straight out of the gate, he has completely dismissed any cause of failure aside from a time dependent material behavior.
I'm going to continue reading this, but it is completely obvious from the first paragraph that the paper is framed in such a way that any question of causes that are outside the scope of the official explanation are dismissed before the research has even started.
This is not science, it is using a scientific title to rationalize a pre-coneived theory for the failure of a system.
In other words, this paper in no way invalidates any theories (and they are just theories) of explosives or any other outside elements being introduced to the system -- because the paper states outright from the opening statement that no such possibilities will be considered.
This engineer essentially states that "The very fact that the buildings survived the crash of the planes into the buildings," suggests that nothing could be responsible for the collapse except "a time dependent behavior at the material level."
Where is this logical leap proven? When have you ever seen a scientific paper make such a statement without conclusive evidence being provided to support said assumption?
Hopefully he will provide an explanation for this reasoning later in the paper, to clarify why he limited the scope of his research to time-dependent material behaviors. Otherwise it is completely useless for the purposes of this debate.