4. B modeling#

4.1. Characteristics of modeling#

Discrete elements of stiffness, damping and mass.

_images/Object_13.svg

Characteristics of the elements:

DISCRET:

nodal mass

M_T_D_N

linear stiffness

K_T_D_L

linear amortization

A_T_D_L (\(c\mathrm{=}\mathrm{0,01}{c}_{\mathit{critique}}\))

Boundary conditions: at node \(\mathrm{N1}\) DDL_IMPO DX = DY = DZ = 0.

Node names: \({P}_{1}=\mathrm{N1}\), \({P}_{2}=\mathrm{N2}\).

Calculation methods:

  • Integration on a modal basis with Fu-Devogelaere

No time \(\Delta t\mathrm{=}{10}^{\mathrm{-}3}s\)

  • Integration on a modal basis with 2nd order adaptive \(\Delta t\)

No initial time \(\Delta t\mathrm{=}{10}^{\mathrm{-}5}s\)

Maximum pitch \(\Delta t\mathrm{=}{10}^{\mathrm{-}3}s\)

Observation time: \(5s\).

4.2. Characteristics of the mesh#

Number of knots: 2

Number of meshes and type: 1 mesh SEG2

4.3. Tested sizes and results#

  • Move point \(B\)

Move

Move

Move

Time

Reference

DEVOG

Tolerance

ADAPT_ORDRE2

Tolerance

(\(s\))

(\(m\))

Aster (\(m\))

(%)

Aster (\(m\))

(%)

0.06

3.06503 E—4

3.06503 E—4

3.06503 E—4

3.06503 E—4

0.5%

0.13

—5.93807 E—4

—5.93807 E—4

0.5%

—5.93729 E—4

0.5%

0.25

—1.178772 E—3

—1.178772 E—3

0.5%

—1.17890 E—3

0.5%

0.69

2.91788 E—3

2.91788 E—3

2.91788 E—3

2.91744 E—3

0.5%

1.01

—3.83901 E—3

—3.83901 E—3

0.5%

—3.83567 E—3

0.5%

2.32

6.68206 E—3

6.68206 E—3

6.68206 E—3

6.68656 E—3

0.5%

3.64

—8,19821 E—3

—8,19821 E—3

0.5%

—8,204 E—3

0.5%

4.96

9.00847 E—3

9.00847 E—3

0.5%

9.0143 E—3

0.5%

Move

Move

Move

Time

Reference

RUNGE_KUTTA_54

Tolerance

RUNGE_KUTTA_32

Tolerance

(\(s\))

(\(m\))

Aster (\(m\))

(%)

Aster (\(m\))

(%)

0.06

3.06503 E—4

3.06420E-04

3.06420E-04

0.5%

3.06443E-04

0.5%

0.13

—5.93807 E—4

-5.93619E-04

-5.93619E-04

-5.93713E-04

0.5%

0.25

—1.17872 E—3

-1.178373E—3

0.5%

-1.17845E—3

0.5%

0.69

2.91788 E—3

2.91701E—3

2.91701E—3

2.91706E—3

0.5%

1.01

—3.83901 E—3

-3.83786E—3

0.5%

-3.83772E—3

0.5%

2.32

6.68206 E—3

6.68009E—3

6.68009E—3

6.67939E—3

0.5%

3.64

—8,19821 E—3

-8.19578E—3

0.5%

-8.19318E—3

0.5%

4.96

9.00847 E—3

9.00579E—3

0.5%

9.00479E—3

0.5%

  • Point B speed

Speed

Speed

Speed

Time

Reference

DEVOG

Tolerance

ADAPT_ORDRE2

Tolerance

(\(s\))

(\({\mathit{m.s}}^{-1}\))

Aster (\({\mathit{m.s}}^{-1}\))

(%)

Aster (\({\mathit{m.s}}^{-1}\))

(%)

0.04

8.95997 E—3

8.95997 E—3

0.5%

8.9722 E—3

0.5%

0.10

—2.33271 E—2

—2.33271 E—2

0.5%

—2.33499 E—2

0.5%

0.22

—5.20590 E—2

—5.20590 E—2

0.5%

—5.2113 E—2

0.5%

0.66

1.40500 E—1

1.40500 E—1

1.40500 E—1

0.5%

1.40591 E—1

0.5%

1.04

1.99889 E—1

1.99889 E—1

1.99889 E—1

1.99933 E—1

0.5%

2.36

—3.39933 E—1

—3.39933 E—1

0.5%

—3.39725 E—1

0.5%

3.68

4.10585 E—1

4.10585 E—1

4.10585 E—1

4.10585 E—1

0.5%

5.00

—4.4531 E—1

—4.45308 E—1

0.5%

—4.44429 E—1

0.5%

Speed

Speed

Speed

Time

Reference

RUNGE_KUTTA_54

Tolerance

RUNGE_KUTTA_32

Tolerance

(\(s\))

(\({\mathrm{m.s}}^{-1}\))

Aster (\({\mathrm{m.s}}^{-1}\))

(%)

Aster (\({\mathrm{m.s}}^{-1}\))

(%)

0.04

8.95997 E—3

8.89561E—3

0.5%

8.95719E—3

0.5%

0.10

—2.33271 E—2

-2.33194E—2

0.5%

-2.33211E—2

0.5%

0.22

—5.20590 E—2

-5.20435E—2

0.5%

-5.20573E—2

0.5%

0.66

1.40500 E—1

1.40458E—1

0.5%

1.40475E—1

0.5%

1.04

1.99889 E—1

1.99829E—1

1.99829E—1

1.99809E—1

0.5%

2.36

—3.39933 E—1

-3.39832E—1

0.5%

-3.39767E—1

0.5%

3.68

4.10585 E—1

4.10463E—1

4.10463E—1

4.10403E—1

0.5%

5.00

—4.4531 E—1

-4.45308E—1

-4.45308E—1

-4.45145E—1

0.5%

4.4. notes#

The results are tested at the peak level where the values are the most significant.

The observation period chosen allows you to see the effect of amortization. However, in this interval, the response of point \(B\) still remains transient but we are close to the steady state whose displacement amplitude is \({10}^{\mathrm{-}2}m\).