Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational Principle Involving the Stress Tensor in Elastodynamics   In the mechanics of inviscid conservative fluids, it is classical to generate
the equations of dynamics by formulating with adequate variables, that the
pressure integral calculated in the time-space domain corresponding to the
motion of the continuous medium is stationary. The present study extends this
principle to the dynamics of large deformations for isentropic motions in
thermo-elastic bodies: we use a new way of writing the equations of motion in
terms of potentials and we substitute the trace of the stress tensor for the
pressure term.

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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
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The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat