CQAXIG

Format

Example

Definitions

Comments

1. Element identification numbers must be unique with respect to all other element identification numbers.
2. The property card entry to reference is PAXIG, which assigns the material and the axis-of-symmetry to the element.
3. In comparison with 2d axisymmetric elements CQAXI and CTAXI (which have two degrees of freedom at each node), general axisymmetric elements have an additional degree of freedom at each node circumferentially; they can also have torsional deformation about the axis-of-symmetry.
4. The grid ordering of G1 through G8 is defined as shown in Figure 1. All grids and the axis-of-symmetry must be on the same plane, and the grids cannot span across the axis-of-symmetry on this plane.

   
   
   Figure 1. CQAXIG Definition

5. If the PAXIG entry referenced in field 3 references a MAT3 entry, material properties and stresses are always given in the x_m-z_m coordinate system.
6. A concentrated load (as in, the load specified on a FORCE entry) at a grid Gi of this element denotes that force applied onto the circumference with radius of Gi. For example, to apply a load of 200 N/m on the circumference at Gi located at a radius of 0.4 m, the magnitude of the load specified on the static load entry is:
   $$\left(\text{200N/m}\right)\text{*}\text{2π}\text{*}\left(\text{0}\text{.4m}\right)\text{=}\text{502}\text{.655N}$$
7. General axisymmetric elements are supported in linear analyses (including static and dynamic analyses) and linear static preloading subcases.
8. 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.