commit:futur:db
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commit:futur:db [2018/07/03 12:04] – [Data extraction] boemer | commit:futur:db [2018/07/17 12:03] (current) – boemer | ||
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- | ====== Commit 2018-07-03 ====== | + | ====== Commit 2018-07-17 ====== |
- | In this commit, the Metafor component of the new coupling procedure with Metalub is added. | + | ===== Description ===== |
+ | In this commit, the out-of-plane thickness evolution in the generalized plane strain state is coherently accounted for in the computation. | ||
- | ===== Versions and folder structure ===== | ||
- | This commit is related to the commits 1454 to 1456 of Metalub. | ||
- | The Metafor component | + | In the previous figure, the square is represented in 3D although the computation is performed in the generalized plane strain state. |
- | Concerning the folder structure, the Metafor component of the new coupling procedure with Metalub can be found in the folder '' | ||
+ | ===== Test case ===== | ||
- | ===== Geometry/ | + | The test case in the following figure is identical to what was decribed previously. |
- | The finite element model is constructed in a plane, which is normal to the rolling direction. | ||
- | **Add figure!!!** | ||
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- | It is important to notice that these points should not be taken into account in the computation of the mean line position, nor that of the relative contact area. | ||
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- | The upper edge of the strip and the lower edge of the roll are represented by linear segments. This could lead to contact detection problems depending on the particular geometry of the roll's edge. Currently, the profiles (without extensions for the roll) are, however, represented by single line segments, for which contact detection is relatively trivial. | ||
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- | ===== Mesh ===== | ||
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- | The mesh of the strip portion $S_{1}$ is a quadrilateral mesh parameterized by $n_{x}$, $n_{y}$ and $r_{ny}$, the number of elements along $\mathbf{x}$, | ||
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- | ===== Material ===== | ||
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- | The material law is the same than in the Metalub computation. | ||
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- | ===== Boundary conditions ===== | ||
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- | The following figure illustrates the boundary conditions of the FE model: | ||
- | * The edge which represents the roll profile is fixed in space. | ||
- | * The lateral edges of the strip can move only along the vertical axis. | ||
- | * The displacements of all nodes on the lower edge of the strip portion is identical along $\mathbf{z}$. | ||
- | * The evolution of the interface pressure $p_{i}$ is applied to the lower edge of the strip, which pushes it against the contact tool. | ||
- | * The evolution of the lubricant pressure $p_{l}$ is applied to the upper edge of the strip, which pushes it downwards. | ||
- | * The evolution of the out-of-plane elongation $\epsilon_{x}$ is applied to the strip portion. | ||
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- | The evolutions of $p_{i}$, $p_{l}$ and $\epsilon_{x}$ along the roll bite can be transformed into evolutions along time, simply by assuming that $x = t$, which is possible since the material model is independent of time. The velocities in the model should also be sufficiently small to have negligible inertial effects. | ||
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- | **Add figure!!!** | ||
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- | ===== Data extraction ===== | ||
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- | During the evolution of the interface pressure and the strip elongation, the relative contact area $A$ and the distance between updated mean lines $h_{t}$ is computed. | ||
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- | Different ways of computing the relative contact area are possible. | ||
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- | **Add figure!!!** | ||
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- | In this coupling procedure, the approach illustrated in the following figure was not only implemented to obtain a more objective measure of the relative contact area, but also to have a smoother evolution of the relative contact area, i.e. previously, the contact area increased suddenly by the nodal contact area, when the respective node of the strip got in contact with the roll. Although this smoothness intuitively seems to lead to better results, this has still to be tested. | ||
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- | **Add figure!!!** | ||
+ | The gap can be computed in various ways, numerically, | ||
+ | * '' | ||
+ | * '' | ||
+ | * '' | ||
+ | In all three cases, the gap should be the same. |
commit/futur/db.txt · Last modified: 2018/07/17 12:03 by boemer