Reminder ===== **Mass calculation process added by modal synthesis** * Calculation of the natural modes of substructure 1 (mesh left cylinder) with interfaces blocked by CALC_MODES * Definition of two dynamic interfaces such as CRAIG - BAMPTON (imposed unit displacement): 'EST': corresponds to point :math:`\mathrm{PBLOC2}=L` 'SUD': corresponds to point :math:`\mathrm{PBLOC4}=G` * Definitions of 2 modal bases associated with these interfaces: operator DEFI_INTERF_DYNA [:ref:`U4.55.03 `]: .. csv-table:: ":math:`\mathrm{BAMO1}`:", "two dynamic modes and one constrained mode: unit displacement on :math:`\mathrm{PBLOC2}=L`" ":math:`\mathrm{BAMO2}`:", "two dynamic modes and one constrained mode: unit displacement on :math:`\mathrm{PBLOC4}=G`" * Definitions of 2 macroelements associated with these modal bases: operator MACR_ELEM_DYNA [:external:ref:`U4.55.05 `] * Definition of the generalized model: operator DEFI_MODELE_GENE [:external:ref:`U4.55.06 `]: Sub_structure_1: :math:`\mathrm{CYLINDR0}`: corresponds to the left cylinder (meshed) Sub_structure_2: :math:`\mathrm{CYLINDR1}`: corresponds to the right cylinder (not meshed) This second substructure is deduced from the first by rotation of −90°. ANGL_NAUT: (-90.,0.,0.) Link: :math:`\mathrm{EST}` and :math:`\mathrm{SUD}` This definition of the two substructures allows DEFI_MODELE_GENE to calculate the translation between the two substructures. * Creation of a full sky line profile based on the generalized model defined: operator NUME_DDL_GENE [:external:ref:`U4.55.07 `] * Assembly of generalized stiffness and mass matrices: operator ASSE_MATR_GENE [:external:ref:`U4.55.08 `] * Calculation of the mass matrix added from the Generalized Model defined: The modal bases attached to each of the two substructures define fields at the displacement nodes at the location of the 1st substructure in the mesh. The operator CALC_MATR_AJOU [:external:ref:`U4.55.10 `] transports the field to the nodes corresponding to the modal base of the second substructure via the translation and rotation defined above to assign it to the location of the second substructure in the mesh. The calculation of the added mass is therefore carried out following this field displacement at the nodes: it is thus possible to calculate the mass added on the 1st substructure, the mass added on the second substructure as well as the term of coupling between the two substructures, taking into account the fluid environment of each of the substructures. * Summation of the generalized assembled mass matrix to the added mass matrix: COMB_MATR_ASSE [:ref:`U4.53.01 `] * Calculation of the natural modes of the submerged global structure: CALC_MODES [:ref:`U4.52.02 `].