13.209. SHELL209 - 3-Node Axisymmetric Shell

Matrix or Vector	Shape Functions	Integration Points
Stiffness and Stress Stiffness Matrix; and Thermal and Newton-Raphson Load Vectors	Equation 11–19, Equation 11–20, and Equation 11–24	Along-the-length: 2 Thru-the-thickness: 1, 3, 5, 7, or 9 per layer
Mass Matrix and Pressure Load Vector	Same as stiffness matrix	Along-the-length: 3 Thru-the-thickness: 1, 3, 5, 7, or 9 per layer

Load Type	Distribution
Element Temperature	Linear along length and linear thru thickness
Nodal Temperature	Linear along length and constant thru thickness
Pressure	Linear along length

References: Ahmad([1]), Cook([5])

13.209.1. Other Applicable Sections

Structures describes the derivation of structural element matrices and load vectors as well as stress evaluations.

13.209.2. Assumptions and Restrictions

Normals to the centerline are assumed to remain straight after deformation, but not necessarily normal to the centerline.

13.209.3. Shear Correction

The element uses an equivalent energy method to compute shear-correction factors. These factors are predetermined based on the section lay-up at the start of solution.