Modeling A ============== Characteristics of modeling ----------------------------------- We use Timoshenko's right beam element: POU_D_T .. image:: images/100014FE0000297200000A3B2B8B517498B7B1B2.svg :width: 534 :height: 132 .. _RefImage_100014FE0000297200000A3B2B8B517498B7B1B2.svg: **Problem 1:** .. csv-table:: "Cutting:", "beam :math:`\mathrm{AB}`: 40 meshes SEG2" "Boundary conditions: In all the knots in :math:`A`: in :math:`B`:", "DDL_IMPO =( GROUP_NO = 'AB', DZ=0., DRX =0, DRY =0.) (NOEUD ='A', DX=0., D=0.) (NOEUD ='B', DY=0.)" **Problem 2:** .. csv-table:: "Cutting:", "beam :math:`\mathrm{AB}`: 40 meshes SEG2 2 rigid elements :math:`\mathrm{AC}`, :math:`\mathrm{BC}`: 2 meshes SEG2" "Boundary conditions: In all the knots in :math:`C`: in :math:`D`:", "DDL_IMPO = (TOUT =' OUI ', DZ=0., DRX =0, DRY =0.) (NOEUD ='C', DX=0., DY=0.) (NOEUD ='D', DY=0.)" .. csv-table:: "Node names:", "Point :math:`A` = :math:`\mathrm{N100}` Point :math:`B` = :math:`\mathrm{N200}` ", "Point :math:`C` = :math:`\mathrm{N300}` Point :math:`D` = :math:`\mathrm{N400}`" Characteristics of the mesh ---------------------------- .. csv-table:: "Number of knots:", "43" "Number of meshes and types:", "42 SEG2" notes --------- Definition of rigid beams :math:`\mathrm{AC}` and :math:`\mathrm{BD}`: * Section: :math:`\mathrm{Hy}=0.2`, :math:`\mathrm{Hz}=0.2`. * Material: :math:`E={2.10}^{16}`, :math:`\rho =0`. Tested sizes and results ------------------------------ **Frequency (** :math:`\mathrm{Hz}` **)** .. csv-table:: "**Clean Mode**", "**Reference**", "**Aster**", "**Tolerance**" "**Problem 1**", "", "" "flexure 1", "431.555", "431.8916", "0.2%" "traction 1", "1265.924", "1266.0056", "0.2%" "flexure 2", "1498.295", "1500.7635", "0.2%" "flexure 3", "2870.661", "2873.5344", "0.2%" "traction 2", "3797.773", "3799.9692", "0.2%" "flexure 4", "4377.837", "4370.8206", "0.2%" .. csv-table:: "**Clean Mode**", "**Reference**", "**Aster**", "**Tolerance**" "**Problem 2**", "", "", "" "1", "392.8", "394.4774", "0.5%" "coupling 2", "922.2", "922.6072", "0.1%" "flexure 3", "1592.0", "1638.2311", "3%" "traction 4", "2629.2", "2778.7000", "5.8%" "compression 5", "3126.2", "3261.6699", "4.5%" We calculate the kinetic energy of the first beam element connected to point :math:`A` of problem 1: .. csv-table:: "**Option**", "**Component**", "**Reference (** NON_REGRESSION **)**", "**Aster**", "**% difference**" "ECIN_ELEM "," TOTALE ", "51366.0", "51366.027", "1%" notes --------- Calculations made by: Problem 1: .. code-block:: text CALC_MODES OPTION =' AJUSTE ' CALC_FREQ =_F (FREQ =( 430., 4500.)) Problem 2: .. code-block:: text CALC_MODES OPTION =' AJUSTE ' CALC_FREQ =_F (FREQ =( 380., 300.)) **Contents of the results file:** Problem 1: 6 first natural frequencies, eigenvectors and modal parameters. Problem 1: 5 first natural frequencies, eigenvectors and modal parameters.