Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Role of Compaction Ratio in the Mathematical Model of Progressive
  Collapse   We derive a mathematical model of progressive collapse and examine role of
compaction. Contrary to a previous result by Ba\v{z}ant and Verdure, J. Engr.
Mech. ASCE 133 (2006) 308, we find that compaction slows down the avalanche by
effectively increasing the resistive force. We compare currently available
estimates of the resistive force, that of Ba\v{z}ant and Verdure (2006)
corrected for compaction for World Trade Center (WTC) 2, and of Beck,
www.arxiv.org:physics/0609105, for WTC 1 and 2. We concentrate on a damage wave
propagating through the building before the avalanche that figures in both
models: an implicit heat wave that reduces the resistive force of the building
by 60% in Ba\v{z}ant and Verdure (2006), or a wave of massive destruction that
reduces the resistive force by 75% in Beck (2006). We show that the avalanche
cannot supply the energy to the heat wave as this increases the resistive force
by two orders of magnitude. We thus reaffirm the conclusion of Beck (2006) that
the avalanche is initiated in the wake of the damage wave.

27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an