Bulk Data Entry Defines an axisymmetric triangular cross-section ring element.


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CTAXI 111 2 31 74 75 32 51 52


Field Contents SI Unit Example
EID Unique element identification number.

No default (Integer > 0)

PID A PAXI entry identification number.

Default = EID (Integer > 0)

G1, G3, G5 Identification numbers of connected corner grid points (by default). Cannot be omitted. See SYSSETTING,AXEGORD for more information.

No default (Integers > 0, all unique)

G2, G4, G6 Identification numbers of connected edge grid points (by default). Can be omitted. See SYSSETTING,AXEGORD for more information.

Default = blank (Integers > 0, all unique)

Theta Material orientation angle in degrees.

Default = 0.0 (Real)


  1. Element identification numbers must be unique with respect to all other element identification numbers.
  2. All the grid points must be in the x-y plane or in the x-z plane of the basic coordinate system with x = r ≥ 0. The grid points must be ordered consecutively starting at a corner grid point and proceeding around the perimeter in either direction.

    Corner grid points G1, G3 and G5 must be present. The edge points G2, G4 and G6 are optional. If any of the edge points are present, they all must be used.

    Note that this information is consistent only for the default SYSSETTING,AXEGORD,0. If this is switched to 1, then the corresponding grid point references should be interpreted accordingly.

    Figure 1. CTAXI Definition

  3. The continuation line is optional.
  4. If the PAXI entry referenced in field 3 references a MAT3 entry, material properties and stresses are always given in the (xm, zm) coordinate system shown in the figure above.
  5. A concentrated load (for example, the load specified on a FORCE entry) at a grid Gi of this element denotes that applied onto the circumference with radius of Gi. For example, in order to apply a load of 200N/m on the circumference at Gi which is located at a radius of 0.4m, the magnitude of the load specified on the static load entry must be:
    200N/m * * 0 .4m = 502 .655N MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaceaadaaakeaadaqadaqaaiaajkdacaqIWaGaaKimai aaj6eacaqIVaGaaKyBaaGaayjkaiaawMcaaiaaykW7caqIQaGaaGPa VlaajkdacaqIapGaaGPaVlaajQcacaaMc8+aaeWaaeaacaqIWaGaaK OlaiaajsdacaqITbaacaGLOaGaayzkaaGaaGPaVlaaj2dacaaMc8Ua aKynaiaajcdacaqIYaGaaKOlaiaajAdacaqI1aGaaKynaiaaj6eaaa a@503E@
  6. CTAXI and CTRIAX6 elements cannot be used simultaneously in an input model.
  7. Axisymmetric elements are supported only for Linear Static, Nonlinear Static (small and large displacement) and Heat Transfer (linear and non-linear, steady-state, and transient) Analysis. Currently, axisymmetric elements are not supported for Inertia Relief Analysis in Large Displacement Nonlinear Analysis.
  8. Axisymmetric elements are supported only for size optimization (only material property – DVMREL1, DVMREL2) and shape optimization, using stress responses. Refer to DRESP1 - Static Stress/Strain Item Codes for more details.
  9. The element grids numbering scheme is controlled by SYSSETTING,AXEGORD,0/1.
    SYSSETTING,AXEGORD Corner Grid Points Edge Grid Points
    C1 C2 C3 E1 E2 E3
    0 (default) G1 G3 G5 G2 G4 G6
    1 G1 G2 G3 G4 G5 G6
  10. PARAM,AXI2DTOR,YES can be used to convert 2D axisymmetric elements CQAXI and CTAXI in the model to general axisymmetric elements CQAXIG and CTAXIG, respectively, while PAXI is considered as PAXIG, which allows the elements to have torsional deformation about the axis-of-symmetry.
    Note: With this option, the elements may need additional constraints in the out-of-plane direction to eliminate rigid body motions. Currently this option is supported only for linear analyses (including static, dynamic and preloading analyses).
  11. This card is represented as an element in HyperMesh.