6. D modeling#

6.1. Characteristics of modeling#

The symmetry of the problem makes it possible to represent only a quarter of the model in 3D: The sphere and the block are represented respectively by a quarter sphere and a quarter of a cylinder, meshed with 3D solid elements CUB8.

A node-mesh contact is defined between the sphere and the block.

An imposed displacement load is applied to the upper part of the sphere, which is rigidified by a high Young’s modulus.

_images/100000000000015E00000190A4972D35F145E88B.png

Boundary condition:

  • Symmetry conditions:

the nodes located in plane \((O,y,z)\) (node groups \(«\mathrm{SBYZ}»\) and \(«\mathrm{SSYZ}»\)) are blocked in the direction \(X\) (DX= 0),

the nodes located in plane \((O,x,y)\) (node groups \(«\mathrm{SBXY}»\) and \(«\mathrm{SSXY}»\)) are blocked in the direction \(Z\) (DZ= 0).

  • Embedding the base:

the nodes of \(«\mathrm{BASE}»\) (plane \(Y=0.\)) are blocked in the directions \(X\), \(Y\), and \(Z\) (DX = DY = DZ = 0).

  • Rigid body movements are suppressed by imposing a following link y between node \(E\) belonging to the sphere and node \(S\) belonging to the massif.

Loads:

An imposed displacement is applied to the upper part of the sphere (group of nodes \(«\mathrm{CHIMPO}»\)) in the direction \(Y\): Loading from 0 to \(–100.\mathrm{mm}\)

6.2. Characteristics of the mesh#

Number of knots: 6993

Number of meshes and type: 5544 HEXA8, 407 PENTA6 and 191 QUAD4

6.3. Tested values#

Identification

Movations

Reference

Aster

% tolerance

Reaction \((N)\)

\(d=–20\mathrm{mm}\)

—3.201351E+06

-3.82828724E+06

25

Reaction \((N)\)

\(d=–40\mathrm{mm}\)

—6.402702E+06

-7.38942843E+06

20

Reaction \((N)\)

\(d=–60\mathrm{mm}\)

—9.604053E+06

-1.06420713E+07

15

Reaction \((N)\)

\(d=–80\mathrm{mm}\)

—1.280540E+07

-1.28912992E+07

10

Reaction \((N)\)

\(d=–100\mathrm{mm}\)

—1.600675E+07

-1.56376456E+07

5

6.4. notes#

The results are almost identical to those of modeling C. But the calculation is even more tedious because a quarter of the sphere is meshed.