Figure 1. shows a generalized HUB for the wind turbine. This is a simple model which has been created by ALDOTT and simplified in order to show the Hub strength FEM calculation procedure.

### Mesh

The maximum equivalent stress like von-Mises stress has occurred at the outer surface of components. Therefore, hexagonal meshes on the surface give much better results than tetrahedral mesh on the solid body according to FEM theory. ALDOTT uses HEX-DOMINANT mesh scheme of which all outer surfaces of the solid body are composed of hexagonal and internal rest of body has tetrahedral meshes.

Bearing loads MACRO at pitch bearing rings

!****************************************************************** ! The SAMPLE of EXTREME load MACRO !******************************************************************

MX_1=500e6
MY_1=40e6

FX_1=8e3

FY_1=-50e3
MX_2=-230e6
MY_2=-1050e6

FX_2=-70e3 FY_2=20e3 FZ_2=200e3

MX_3=-100e6
MY_3=70e6

FX_3=7e3 FY_3=20e3 FZ_3=160e3

*DO,f,1,3,1 CMSEL,S,FLANGE%i%

CSYS,199+i MX=MX_%i%

MY=MY_%i%

FX=FX_%i% FY=FY_%i% FZ=FZ_%i%

*GET,NODE_TOT,NODE,,COUNT *GET,NMIN,NODE,,NUM,MIN

PCD = NX(NMIN)

. . . . .

/SOLU SOLVE FINISH /EOF