Dear experts
I have a hollow cylinder modeled in ANSYS APDL. I need to provide material properties which are in cylindrical coordinate as Er = 1000, Etheta = 2000 and Ez = 5000 with their corresponding Poisson's ratio as nur(theta) = 0.123, nur(z) = 0.0143, nu(theta)z = 0.141. Do I need to change the active CS to cylindrical CS or, do I need to use the coordinate system as Er = Ex; Etheta = Ey; Ez = Ez where z represents the axis of the cylinder; x and y are two transverse directions.
Thank you for sharing the model. Why are the shear moduli G_xy, G_yz and G_xz identical to zero? The density of the material is missing. What about boundary conditions?
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,EX , 1, 1, 1000.00000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,EY , 1, 1, 2000.00000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,EZ , 1, 1, 5000.00000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,GXY , 1, 1, 0.00000000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,GYZ , 1, 1, 0.00000000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,GXZ , 1, 1, 0.00000000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,PRXY, 1, 1, 0.123000000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,PRYZ, 1, 1, 0.141000000 ,
MPTEMP,R5.0, 1, 1, 0.00000000 ,
MPDATA,R5.0, 1,PRXZ, 1, 1, 1.430000000E-02,
Dr Nils Wagner Thanks for the query regarding shear moduli and density of the material. The information regarding the shear moduli and density of the material is not mentioned in the literature. There they have provided only the orthotropic material properties in cylindrical coordinate and their corresponding Poisson's ratio. In boundary conditions, it is assumed that the top surface of the cylinder is constrained in all directions and uniform pressure of say 500 MPa is applied on the bottom surface along the axial direction.
You have Ez = Ez in Cartesian and in cylindrical CS. But you cannot set Er = Ex; Etheta = Ey because after theta=pi/2 you have Er = Ey; Etheta = Ex.
You also need the shear moduli because for orthotropic material they cannot be calculated from Young's modulus and Poisson's ratio as it is done for isotropic material.
Thanks for the reply Prof Staat. In that case Prof Staat, how to implement the same in ANSYS APDL....In APDL as per my knowledge there is no option to directly put material property in cylindrical coordinate.
Sorry, I have no experience with a FEM code that can use cylindrical coordinates.
If shear moduli cannot be found for orthotropic material, some people guess G_ij=E_i/2/(1+v_ij). This holds for isotropic materials and for one of the shear moduli of transversely isotropic materials. But it does not hold for orthotropic material. If you follow this guess, please do not say that I have suggested it.
The guess cannot hold because G_ij=G_ji but v_ij/E_i=v_ji/E_j.
- Badges
- Science topic