commit:futur:db

# Differences

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commit:futur:db [2018/07/12 12:00] – [Test cases] boemer | commit:futur:db [2018/07/17 11:45] – [Test case] boemer | ||
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- | ====== Commit 2018-07-12 ====== | + | ====== Commit 2018-07-17 ====== |

- | In this commit, a new contact traction element was created to set the traction force to zero at the nodes that are in contact within a specified contact interaction. | + | ===== Description ===== |

+ | In this commit, the out-of-plane thickness evolution in the generalized plane strain state is coherently accounted for in the computation. | ||

- | ===== How to use the new feature ===== | ||

- | A '' | ||

- | prp = ElementProperties(ContactTraction2DElement) | + | In the previous figure, the square was represented in 3D although the computation is performed in the generalized plane strain state. The lateral movement of the left and right sides of the square is blocked. A pressure $p$, identical in both cases, pushes the square against to contact tool (frictionless). When the out-of-plane thickness of the square increases, as shown on the right, the resultat force created by the pressure increases due to the increase of the surface on which this pressure is applied. Moreover, if the increase of the out-of-plane thickness is not taken into account in the contact interaction,in the computation of the area in contact, the increase of the resultat pressure force will increase the gap. Hence, $\text{gap}_{1} < \text{gap}_{2}$ previously. . |

- | prp.put(PRESSURE,p[') | + | |

- | prp.put(NBR_CONTACT_INTERACTION, 3) | + | |

- | | + | |

- | Hence, if nodes in this ''in contact (in the previous mechanical iteration) in the contact interaction 3, the traction force applied to these nodes is set to zero. | + | |

- | ===== File structure ===== | + | ===== Test case ===== |

- | Instead of implementing the new feature directly in the '' | + | The test case in the following figure is identical to what was decribed previously. A square is pushed against a contact tool (frictionless) by a constant pressure $p$, its lateral movement is blocked and its out-of-plane thickness increases. |

- | | + | |

- | Some minor modifications: | + | |

- | * The new property ''in '' | + | |

- | * It was necessary to add '' | + | |

- | * Untabify in '' | + | |

- | * '' | + | |

- | * The method '' | + | |

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- | ===== Implementation ===== | + | |

- | | + | |

- | Concerning the implementation,the following virtual functions: | + | |

- | * ''is found, pointers to the slave nodes corresponding to the nodes of the '' | + | |

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- | * '' | + | |

- | | + | |

- | * ''was defined for the ''. Hence, this function can return '' | + | |

- | | + | |

- | * ''is used first and then the rows corresponding to the traction forces that were set equal to zero are also set equal to zero. The structure of this matrix is illustrated in a comment of the '' | + | |

- | | + | |

- | ===== Test cases ===== | + | |

- | | + | |

- | Two test cases were created in the folder '' | + | |

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- | | + | |

- | As shown in the previous figure, two squares are crushed by a compression pressure and a contact tool that moves downwards by $2 \; dy$. In the case on the left, the traditional ''is used, while the new ''and contact) is computation in the extractor ''of the cases with the ''. | + | |

+ | The gap can be computed in various ways, numerically, | ||

+ | * First, the numerical computation simply consists in extracting the gaps in the Metafor computation and choosing the one at $P_{4}$. | ||

+ | * Second, the analytical computation provides the value of the gap via the following formula: $\text{gap} = p/k_{n}$, where $k_{n}$ is the normal penalty coefficient. | ||

+ | * Thirdly, the semi-analytical/ |

commit/futur/db.txt · Last modified: 2018/07/17 12:03 by boemer