{"id":369069,"date":"2024-05-29T14:05:04","date_gmt":"2024-05-29T14:05:04","guid":{"rendered":"\/forum\/forums\/topic\/which-beam-properties-to-use-to-build-a-beam-with-arbitrary-sections\/"},"modified":"2024-05-29T14:13:17","modified_gmt":"2024-05-29T14:13:17","slug":"which-beam-properties-to-use-to-build-a-beam-with-arbitrary-sections","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/which-beam-properties-to-use-to-build-a-beam-with-arbitrary-sections\/","title":{"rendered":"Which beam properties to use to build a beam with arbitrary sections"},"content":{"rendered":"

Hey gals and guys,<\/p>\n

I am about to build up a beam for a wind turbine blade. I have a cross sectional analysis tool that gives me the 6×6 stiffness and mass matrices of the blade cross sections. These can be extracted for diferent reference systems.<\/p>\n

    \n
  1. A coordinate system of the cross section with in a reference point in the cross section as I define it<\/li>\n
  2. In the same coordinate system as defined by me but with the origin moved to the elastic center of the cross section (Additional output: location elastic center)<\/li>\n
  3. In the principal axis system moved to the elastic center of the cross section. (Additional output: location elastic center and angle of principal axes)<\/li>\n<\/ol>\n

    Which matrices should I use? And where do I put the element nodes – elastic center or reference point of cross section?<\/p>\n

     <\/p>\n

    I build the cross section in Ansys classic APDL with the below code. Here X1,Y1,Z1 would be the either the reference point or the elastic center of the cross sections. K is the stiffness matrix and M the mass matrix for the composite cross section.<\/p>\n

        ! nodes
        N,1,X1,Y1,Z1
        N,2i,X2,Y2,Z2
        
        ! beam properties
        SECTYPE,      1,COMB,MATRIX,    
        CBMX,1,  K(1,1), K(1,2),  K(1,3),  K(1,4),  K(1,5), K(1,6)
        CBMX,2,              K(2,2),  K(2,3),  K(2,4),  K(2,5), K(2,6)
        CBMX,3,                           K(3,3),  K(3,4),  K(3,5), K(3,6)
        CBMX,4,                                        K(4,4),  K(4,5), K(4,6)
        CBMX,5,                                                     K(5,5), K(5,6)
        CBMX,6,                                                                 K(6,6)
        
        CBMD,1,  M(1,1), M(1,2),  M(1,3),  M(1,4),  M(1,5), M(1,6)
        CBMD,2,              M(2,2),  M(2,3),  M(2,4),  M(2,5), M(2,6)
        CBMD,3,                           M(3,3),  M(3,4),  M(3,5), M(3,6)
        CBMD,4,                                        M(4,4),  M(4,5), M(4,6)
        CBMD,5,                                                     M(5,5), M(5,6)
        CBMD,6,                                                                 M(6,6)
        
        ! elements
        SECNUM,1
        E,1,1,2<\/p>\n

     <\/p>\n

    Thank you for your help \ud83d\ude42<\/p>\n","protected":false},"template":"","class_list":["post-369069","topic","type-topic","status-closed","hentry","topic-tag-beam","topic-tag-beam-analysis-1","topic-tag-beam188","topic-tag-composite","topic-tag-cross-section"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t