ELBOW elements

This problem contains basic test cases for one or more Abaqus elements and features.

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ProductsAbaqus/Standard

General loading

Problem description

Model:

Length 15.0
Elbow section data ro = 10.0, t = 1.0
Centrifugal axis of rotation (0, 0, 1) through midspan
Gravity load vector (0, 0, 1)

Material:

Young's modulus 3 × 106
Poisson's ratio 0.3
Density 1.0
Coefficient of thermal expansion 0.0001

Initial conditions

Initial temperature ALL, −10.0

General:

The boundary condition NODEFORM is used for load types BX, BY, BZ, GRAV, CENT, CENTRIF, and ROTA on ELBOW31 and ELBOW32 elements, preventing cross-sectional deformations.

Results and discussion

The calculated reactions are in agreement with the applied loads.

Closed-end pressure loading

Problem description

Closed-end pressure loading of ELBOW elements is verified. A single element is oriented at 45° to the x- and z-axis in a fluid of density 1 × 103. The magnitude of the acceleration resulting from gravity is 9.8, and the positive hydrostatic pressure gradient is in the negative 3-direction. The test consists of completely constraining all degrees of freedom and recovering the reaction forces under the hydrostatic pressure load on the elbow. According to Archimedes' Principle, the net reaction in the 3-direction should be the buoyant force, which in this case is 2203.04. All other reaction forces and moments should sum to zero. The results also indicate that the directions of the nonzero reaction forces and moments on individual nodes are correct.

The second test is of a curved elbow with closed-end conditions modeled by an ELBOW element. Internal pressure is applied to the elbow. The reaction forces should sum to 0. in all directions.

Model:

Length 1.0
Elbow section data ro = 0.275, t = 0.025
Effective diameter 0.535
Gravity vector (0, 0, 1)

Material:

Young's modulus 1 × 1010
Poisson's ratio 0.33

Loading:

Uniform pressure magnitude 10.0

Initial conditions

Zero pressure height 0.0
Reference pressure height −2.0
Reference pressure magnitude 1.96 × 104

Results and discussion

The calculated reactions are in agreement with the applied loads.