2. Benchmark solution#

2.1. Reference solution for linear water pressure#

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,

_images/Object_24.svg _images/Object_25.svg

designating the stresses, deformations and water pressures obtained in phase one has:

_images/Object_26.svg

In this writing,

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designates the Biot module and

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.

The conditions at the limits of zero flow and the conservation of the water body give

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The boundary conditions on the side walls and the fact that the stress state is homogeneous give:

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So we finally have to solve the two equations:

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And we get:

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In our case,

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2.2. Development of the analytical solution CJS#

We always have:

for deformations:

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for constraints:

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Elastic phase:

By simply writing the elastic law, it comes:

_images/Object_36.svg _images/Object_37.svg

Moreover, we also know that during this phase

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(\(\mathrm{=}\mathit{trace}(\sigma )\)) remains constant because

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. For the components of the diverter, we deduce:

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and

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either:

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and

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Therefore:

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So when we reach the criterion

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, we have:

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That is to say, the transition between the elastic and perfectly plastic states occurs for an axial deformation equal to:

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The corresponding stress state is noted:

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and

_images/Object_49.svg

Plastic phase:

We note

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The deviator of the inverse of the tensor s

In general, we have the following quantities:

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either:

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and

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Therefore:

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From this we deduce:

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and

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in addition:

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and

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As we have:

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So the tensor

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is written:

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and

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He then comes to

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:

_images/Object_69.svg _images/Object_70.svg

According to the elastic law, we also have:

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and

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where:

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and with:

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and

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or, according to the above, we have for

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:

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And for

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:

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From this we deduce that the deviatory load function is written as:

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Taking into account the fact that

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, we then find for the plastic multiplier:

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What happens with the formulas of

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and

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previous ones:

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The analytical expression of constraints is finally concluded:

By posing:

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We have:

_images/Object_88.svg _images/Object_89.svg

2.3. Benchmark results#

Constraints

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,

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and

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at points \(A\), \(B\), and \(C\).

2.4. Uncertainty about the solution#

Exact analytics solution for CJS1.