Multiple Bird-strikes On Box Structure

Chapter 40: Multiple Bird-strikes on Box Structure

40

Multiple Bird-strikes on Box Structure 

Summary



Introduction



FEM Solution



Pre- and Postprocess with SimXpert



Results



Input File(s)

590 591 593

651 655

598

590 MD Demonstration Problems CHAPTER 40

Summary Title

Chapter 40: Multiple Bird-strikes on Box Structure

Features

• Multi Material Euler • General Lagrangian-Eulerian Coupling • Failed Coupling Surface

Geometry Bird 2 Bird 1

Structure Outer Euler Zone Inner Euler Zone

Material properties

Material

Density

(kg/m3)

Titanium

Air

4527

1.1848

930

930 2.2e9

Mass (kg)

0.36

0.285

Initial Velocity (m/s)

150

200

1.03e11

Poisson’s ratio

0.314

Yield strength (Pa)

1.38e8

Gamma Thickness (m)

1.4 0.0015

Radius (m)

0.25

Length (m)

0.25

Fail (Eq. Plastic Strain)

Boundary conditions

Bird 2

2.2e9

Bulk Modulus (Pa)

Analysis characteristics

Bird 1

0.1

Explicit Transient Dynamic (SOL 700) • Plate Structure fixed at ends • Outer flow on the boundary of outer Euler zone.

Element types

• Multi Lagrange: 4-node shell element • Euler: 8-node hex element which is generated automatically using Mesh entry

FE results

1. Failure at primary structure followed by impact on secondary structure 2. Time history of total z-force on the coupling surface

CHAPTER 40 591 Multiple Bird-strikes on Box Structure

Introduction Bird strike on a box structure is a typical problem in aircraft industries. The box structure simulates the leading edge of lifting surfaces, e.g. wing, vertical, and horizontal stabilizers. The box can be simplified to consist of a curve leading edge panel and a front spar. The acceptable design criteria for bird strike are that the leading edge panel may fail but the front spar strength may not degrade to a certain level. In this example, two cylindrical panels are concentric. Two birds strike the upper panel. One bird strikes in horizontal direction and the second one vertically. The second bird will perforate the first panel and impact the second one. The birds are modeled as cylindrical slugs of jelly. The plate is constrained in such a way that the edges can only move in radial direction.

Bird 2

Bird 1

150 m/s

200 m/s

60o

Figure 40-1

Initial Situations

The properties and initial conditions of the plate and birds are as follows: Plate

Ambient B

Bird 1

Bird 2

Material

Titanium

Air

Jelly

Jelly

Density (kg/m3)

4527

1.1848

930

930

Bulk modulus (Pa)

1.03e11

2.2e9

2.2e9

Poisson’s ratio

0.314

Yield stress (Pa)

1.38e8

Gamma

1.4

Thickness (m)

0.0015

Radius (m)

0.25

592 MD Demonstration Problems CHAPTER 40

Plate Length (m)

Ambient B

Bird 1

Bird 2

0.25

Mass (kg)

0.36

0.285

Initial velocity (m/s)

150

200

Fail (equiv. Plas. Strain)

0.1

Solution Requirements SOL 700 Model Each curved plate is modeled using 33x16 BLT-shells. The boundary conditions applied at the edges of the plate are defined within a cylindrical coordinate system, where the local z-axis is aligned with the length axis of the plate. The cylindrical system is defined using a CORD2C entry. To create a closed surface, required by COUPLING option, the two plates are connected with dummy quad elements. The two birds and air are modeled using Multi Material Eulerian (FV) elements, also known as MMHYDRO. The location of the bird in the Euler domain is defined using TICEUL option. The material for the birds and air are modeled using EOSPOL and EOSGAM, respectively. To allow the bird perforating the first plate and impact the second one, several modeling techniques can be used. One of them is using two Eulerian domains and two coupling surfaces. Both the Eulerian domains and the coupling surfaces have to be logically different. Each coupling surface associates with one Eulerian domain. In this model, the two coupling surfaces share the same physical space. By specifying that one domain is covered outside and the other inside, the Eulerian domain represents the correct physical space. The two Eulerian domains cannot interact with each other except through coupling surfaces. When coupling surfaces share the same shell elements with some or all shells failing, then the material can flow from one Eulerian domain into another one. The interaction between the Eulerian domains is activated using COUP1INT option and PARAM, FASTCOUP, INPLANE, FAIL. The rest of the Euler domain is filled with air. Please notice that when the effect of air is neglected, then the rest of the Eulerian domain should be filled with void. It will speed up the analysis. The first domain is associated with a coupling surface that is INSIDE covered. Therefore, it cannot be adaptive and is defined using MESH,, BOX option. The second domain is adaptive and defined using MESH,, ADAPT. The ADAPT option will let SOL 700 create and update the Eulerian domain to minimize memory allocation and consequently reduced CPU time. The default Eulerian boundary condition is set to that only outflow is allowed using FLOWDEF option. In this case, a bird that reaches the free face boundary will flow out of the domain. The initial velocity of the birds is defined using TICVAL option. The finite element model of the upper and lower plates, the Eulerian domains and the initialization of the birds are shown in the Figure 40-2. The dummy quad elements used to create closed coupling surfaces are not shown in Figure 40-1.

CHAPTER 40 593 Multiple Bird-strikes on Box Structure

FEM Solution

Figure 40-2

Euler Domains

Input File: SOL 700 is an executive control that activates an explicit nonlinear transient analysis: SOL 700,NLTRAN stop=1 Case control cards for problem time, loads, and initial conditions: $ Direct Text Input for Executive Control CEND TITLE = Multiple BIRD STRIKE on BOX Structure SUBCASE 1 $ Subcase name: Default SUBTITLE=Default TSTEPNL = 1 SPC = 1 IC = 1 TSTEPNL is a SOL 700 bulk data entry which describes the number of time steps (10) and time increment (0.0015 seconds) of the simulation. The total time is the product of the two entries. Notice here the time increment is only for the first step. The actual number of time increments and the exact value of the time steps is determined by SOL 700 during the analysis. The time step is a function of the smallest element dimension during the simulation.

$------- BULK DATA SECTION ------BEGIN BULK TSTEPNL 1 10 0.0015 1

594 MD Demonstration Problems CHAPTER 40

Define the Initial, the Minimum and the Safety factor of the time step: PARAM*, DYINISTEP, 1e-7 PARAM*, DYMINSTEP, 1e-8 DYPARAM, STEPFCTL, 0.9 Define coupling surface that can fail and Multi material overflow array to store material data. In a problem where more than 10% of the elements have more than one material, the default value of FMULTI(0.1) must be increased. DYPARAM, FASTCOUP, INPLANE, FAIL DYPARAM, FMULTI, 0.2 Define Output results request for every 0.00015 s and time history output request for coupling surfaces: DYPARAM, LSDYNA, BINARY, D3PLOT, .00015 DYTIMHS,, .000001,,,,,,,+ +, CPLSOUT Euler domain 1: Define an Euler mesh with 50x28x44 elements reference to PEULER1 (=1): $ domain 1 $ MESH, 1, BOX,,,,,,,+ +,-0.26,-0.015,-0.05,0.50,0.28,0.44,,,+ +, 50, 28, 44,,,, EULER, 1 Define FSI coupling surface from elements listed in the BSURF entry (covering inside): $ COUPLING SURFACE 1 $ COUPLE , 1 , 1 , INSIDE , ON , ON , , , , + + , , , , , , , , , + + , , 1 $ BSURF , 1 , 7393 , THRU , 8448 , 13729 , THRU , 14048 , 14577 , + + , THRU , 15236 Define Eulerian element properties with reference to TICEUL1 (=11). PEULER1 , 1 ,

,

MMHYDRO , 11

The initial conditions of these elements are defined in geometric regions.

CHAPTER 40 595 Multiple Bird-strikes on Box Structure

Define Regions with shapes, material, initial values and level indicators: $ Allocation of material to geometric regions. $ -------------------------------------------TICEUL1 , 11 , 11 TICREG , 1 , 11 , CYLINDER , 1 , 3 , 1 TICREG , 2 , 11 , CYLINDER , 2 , 5 , 2 TICREG , 3 , 11 , SPHERE , 4 , 4 ,

, , 5

3 2 ,

1

Define region shapes: CYLINDR , 1 , , .13 , .125 , .2252 , .17 , .125 , .2944 , + + , .035 CYLINDR , 2 , , -.1381 , .125 , .26 , -.2381 , .125 , .26 , + + .035 SPHERE , 4 , , -.1381 , .125 , .26 , 1000 Define Initial values of the birds and the air: TICVAL, TICVAL, TICVAL,

1 2 5

, , ,

, , ,

XVEL , XVEL , SIE ,

-75 , ZVEL , -129.9 200 2.1388E5 , DENSITY , 1.1848

Define Eulerian materials for the birds and the environment (air): $--------Material Bird -----------------------------------MATDEUL , 3 , 930 , 3 EOSPOL , 3 , 2.2e9 MATDEUL , 5 , 930 , 5 EOSPOL , 5 , 2.2e9 $ -------- Material Air id =4 MATDEUL , 4 , 1.1848 , 4 EOSG , 4 , 1.4 Euler domain 2: Define an adaptive Euler mesh reference to PEULER1 (=6): $-----------------------------Domain 2----------------------------$ MESH , 2 , ADAPT , 0.01 , 0.01 , 0.01 , , , , + + , -0.26 , -0.015 , -0.05 , , , , , , + + , , , , , , , EULER , 6

596 MD Demonstration Problems CHAPTER 40

Define FSI coupling surface from elements listed in the BSURF entry (covering outside): $===Coupling Surface 2 $ COUPLE , 2 , 2 , OUTSIDE , , , , , , + + , , , , , , , , , + + , , 2 $ BSURF , 2 , 7393 , THRU , 8448 , 13729 , THRU , , +

14048 ,

14577

Domain 2 has only 1 region with air. TICEUL1,12,12 TICREG,11,12,SPHERE,7,4,5,1.0 SPHERE,7,,0.0,0.0,0.0,500.0 Interaction between the coupling surfaces 1 and 2: Define interaction between coupling surface 2 and 1: $ coupling interaction $ COUPINT,2,2,1 Define default Eulerian flow boundary condition: $ Flow boundary $ ------------------------------------------------------------FLOWDEF , 1 , , MMHYDRO , , , , , , + + , FLOW , OUT Define cylindrical coordinate system: $ -------------------CORD2C , 1 , , 0.0 , 0.0 + , 0.0 , 0.125 , 0.25

,

0.0

,

0.0

,

0.25

,

Define properties of the panels: PSHELL1 , 2 , 2 , Blt , Gauss , 3 , , Mid , , + + , .0015 $ MATD024 , 2 , 4527 , 1.150e11 , .314 , 1.38e8 , , 0.1

.83333

0.0

,

+

CHAPTER 40 597 Multiple Bird-strikes on Box Structure

Define properties of dummy elements to close the coupling surfaces. PSHELL,3,999,1.E-3 PSHELL,4,999,1.E-3 $ MATD009,999,1.E-20

598 MD Demonstration Problems CHAPTER 40

Pre- and Postprocess with SimXpert When aircraft are landing or taking off, they sometimes have difficulties with bird swarms. An impact of several birds striking at a high velocity can cause severe damage to the structure of the aircraft. So, we are going to consider a situation where two birds strike a curves titanium plate at an arbitrary time. Bird 1 hits the plate perpendicularly; bird 2 hits the plate on the lower side at an angle of 25° (Figure 40-3). The birds are modeled as cylindrical jelly masses with the following specifications: Bird 1

Bird 2

Material:

Jelly

Jelly

Density:

r = 930 kg/m3

r = 930 kg/m3

Speed of Sound:

c = 1483 m/s

c = 1483 m/s

Mass:

m2 = .360 kg

m2 = .285 kg

Velocity:

v1 = 150 m/s

v2 = 200 m/s

The plate is constrained on the edges in all directions.

Figure 40-3

Birdstrike

CHAPTER 40 599 Multiple Bird-strikes on Box Structure

Create a New Database Enter the MD Explicit Workspace. a. Click MD Explicit b. Tools: Options c. Select Units Manager d. Select Basic Units (m, kg, s, ...) e. Select GUI Options; check Solver Card f. Click OK g. Click Apply

b

c

d

a

e

f

g

600 MD Demonstration Problems CHAPTER 40

Create Curve 1 a. Geometry: Curve b. Polyline Spline window: Create: select Spline c. Polyline Spline window, Entities: select Pick d. For Entities: X,Y,Z Coordinate, enter 0.2165 0 0.125; click OK e. For Entities: X,Y,Z Coordinate, enter 0.2165 0.25 0.125; click OK f. Click Apply

a

b d

c

f d

e e

CHAPTER 40 601 Multiple Bird-strikes on Box Structure

Create Curve 2 a. For Entities: X,Y,Z Coordinate, enter 0.2165 0 0.001; click OK b. For Entities: X,Y,Z Coordinate, enter 0.2165 0.25 0.001; click OK c. Click Apply d. Click OK

a

c

d

a

b b

602 MD Demonstration Problems CHAPTER 40

Create Surface1 a. Geometry: Revolve b. Revolve Axis: Along, select Vector c. For Locations: X,Y,Z Coordinate, enter 0 0 0; click OK (not shown) d. For Locations: X,Y,Z Coordinate, enter 0 0 1; click OK (not shown) e. For Locations: X,Y,Z Coordinate, enter 1 0 0; click OK f. Click OK g. Revolve Curves: Entities, select CURVE/1 h. For Angle Of Spin (Degrees): enter -120; click OK

a

b

f

e

h

g

CHAPTER 40 603 Multiple Bird-strikes on Box Structure

Create Surface2 a. Geometry: Revolve b. Revolve Axis: Along, select Vector c. For Locations: X,Y,Z Coordinate, enter 0 0 -0.124; click OK (not shown) d. For Locations: X,Y,Z Coordinate, enter 0 0 1; click OK (not shown) e. For Locations: X,Y,Z Coordinate, enter 1 0 0; click OK f. Revolve Curves: Entities, select CURVE/2 g. For Angle Of Spin (Degrees): enter -120; click OK h. Observe results

a

b

e h

g

f

604 MD Demonstration Problems CHAPTER 40

Create Part2 Create surfaces 3, 4, 5, and 6 a. Assemble: Create Part b. For Title: enter PART_2 c. For ID: enter 2; click OK d. Observe in the Model Browser tree: PART_2 e. Surface: Filler f. For Curves: pick CURVE/3; click OK g. For Curves: pick CURVE/7; click OK (not shown) h. Click Apply i. Observe results

a

e

b c h f f i

d

CHAPTER 40 605 Multiple Bird-strikes on Box Structure

Create Surfaces 4, 5, and 6 a. For Curves: pick CURVE/4; click OK b. For Curves: pick CURVE/8; click OK c. Click Apply d. For Curves: pick CURVE/5; click OK e. For Curves: pick CURVE/9; click OK f. Click Apply g. For Curves: pick CURVE/6; click OK (not shown) h. For Curves: pick CURVE/10; click OK i. Click Apply

c

f

i

d a

b

e

h

606 MD Demonstration Problems CHAPTER 40

Show Labels PART_1 a. Right click in the Main Window b. Select Render c. Select Geometry WireFrame d. In the Model Browser: right chick PART_1 e. Select Set Current f. In the Model Browser: right chick PART_1 g. Select Show Only h. Under Tools: select Identify i. In the Pick window, select Curves j. In the Pick window, select Surfaces k. In the Pick window, select Select l. In the Pick window, click All m. In the Pick window, click Done (not shown) n. In the Pick window, click Exit (not shown)

h b

c

a i

j

k l

d

f

g

e

CHAPTER 40 607 Multiple Bird-strikes on Box Structure

Seed PART_1 a. Meshing: Seed b. Type: Number of Elements, enter 20 c. Entity: Curves, pick Curve/3, Curve/4, Curve/7, and Curve/8 d. Click Apply e. Entity: Curves, pick Clear f. Type: Number of Elements, enter 40 g. Entity: Curves, pick Curve/5, Curve/6, Curve/9, (not shown) and Curve/10 h. Click Apply i. Click OK

a

e f

b

d

g

i c c

h

608 MD Demonstration Problems CHAPTER 40

Surface PART_1 a. Meshing: Surface b. Element Type: Mesh Type, select Quad Dominant c. Surface to mesh: pick Surface/1 and Surface/2 d. Element property: Add to part: PART_1 e. Click Apply f. Click OK

a

c b

d

f

e

CHAPTER 40 609 Multiple Bird-strikes on Box Structure

Seed PART_2 a. In the Model Browser: right chick PART_2 b. Select Set Current (not shown) c. In the Model Browser: right chick PART_2 d. Select Show Only (not shown) e. Under Tools: select Identify (not shown) f. In the Pick window, select Curves and Surfaces g. In the Pick window, select Select h. In the Pick window, click All i. In the Pick window, click Done j. In the Pick window, click Exit k. Entity: Curves, pick Clear l. Type: Number of Elements, enter 20 (not shown) m. Entity: Curves, pick Curve/12 (not shown), Curve/14, Curve/16, and Curve/18; click Apply n. Entity: Curves, pick Clear o. Type: Number of Elements, enter 40 (not shown) p. Entity: Curves, pick Curve/20, Curve/22, Curve/24, and Curve/26; click Apply q. Type: Number of Elements, enter 5 r. Entity: Curves, pick Curve/13 (not shown), Curve/17, Curve/19, Curve/21, Curve/23, Curve/25, and Curve/23; click Apply s. Click OK

f

k q

g

m

h i

j p

a

c

s

r

n

610 MD Demonstration Problems CHAPTER 40

Surface PART_2 a. Meshing: Seed b. For Mesh type:, enter Tria Only c. For Surface to mesh, pick Surface/3, Surface/4, Surface/5, and Surface/6 d. Add to part:, enter PART_2 e. Click Apply f. Click OK

a

b c d

f

e

CHAPTER 40 611 Multiple Bird-strikes on Box Structure

Merge Nodes Surface 1 - 6 a. In the Model Browser, right click PART_2 b. Select Show All (not shown) c. Nodes/Elements: Equivalence d. For Entities, select All Nodes e. For Merging Option, select Merge Nodes f. For Merging tolerance, enter 1.e-5 g. Select Keep Lower ID h. Select Delete merged unreferenced nodes i. Click OK j.Click OK

c

d a

e g

f h i

j

612 MD Demonstration Problems CHAPTER 40

Shell Materials a. Materials: MAT[024] MAT_PIECEWISE_LINEAR_PLASTICITY (not shown) b. For Name: enter MATD024_1 c. For MID, enter 1 d. For RHO, enter 4527 e. For E, enter 1.15E11 f. For PR, enter 0.314 g. For SIGY, enter 1.38E8 h. For FAIL, enter 0.1 i. Click Create j. Materials: MAT[020] MAT_RIGID (not shown) k. For Name: enter MATD020_2 l. For MID, enter 2 m. For RHO, enter 7856 n. For E, enter 2.1e+011 o. For PR, enter 0.3 p. Click Create

b c

d

e

f

g

h

i k l

m

n

o

p

CHAPTER 40 613 Multiple Bird-strikes on Box Structure

Shell Properties a. Element Properties: 2D, select PSHELL1 b. For Name: enter PSHELL_1 c. For Card, enter PSHELL1 d. For PID, enter 1 e. For MID, double click, select Select f. For Entity Selection, select MATD024_1; click OK g. For T1, enter 0.0015 h. Click Create i. Materials: MAT[020] MAT_RIGID (not shown) j. For Name: enter PSHELL_2 k. For Card, enter PSHELL2 l. For PID, enter 2 m. For MID, double click, select Select (not shown) n. For Entity Selection, select MATD020_2; click OK (not shown) o. For T1, enter 0.0015 p. Click Create

b c

d

e

a g

f

h

j k

l o p

614 MD Demonstration Problems CHAPTER 40

Shell Properties Change Region a. Right click PART_1, select Show Only b. Right click PSHELL_1, select Properties c. Click Change Region d. Screen select All Elements e. Click Done f. Click Modify g. Repeat steps a through f for PART_2

b

b e

c a f g

CHAPTER 40 615 Multiple Bird-strikes on Box Structure

Euler Properties a. Element Properties: EOS, select [12] EOS Ideal Gas b. For Name: enter EOSGAM_1 c. For PID, enter 1 d. For GAMMA, enter 1.4 e. Click Create f. Element Properties: EOS, select [01] EOS Linear Polynomial g. For Name: enter EOSPOL_2 h. For PID, enter 2 i. For A, enter 2.2E9 j. Click Create

a b c

d e

f

g h

i

j

616 MD Demonstration Problems CHAPTER 40

Euler Materials Air material a. Materials: Eulerian, select Eulerian Material b. For Name: enter MATDEUL_3 c. For MID, enter 3 d. For RHO, enter 1.1848 e. Double click EID, select Select (not shown) f. For Entity Selection, select EOSGAM_1; click OK g. Click Create

a

b c

d

e

g

f

CHAPTER 40 617 Multiple Bird-strikes on Box Structure

Euler Materials Bird material a. Materials: Eulerian, select Eulerian Material b. For Name: enter MATDEUL_4 c. For MID, enter 4 d. For RHO, enter 930 e. Double click EID, select Select (not shown) f. For Entity Selection, select EOSPOL_2; click OK g. Click Create

a

b c

d

e

g

f

618 MD Demonstration Problems CHAPTER 40

Create Mesh Creation of Mesh 1 (modeling Outside Box Euler) a. LBCs: Eulerian, select Mesh b. For Name: enter Mesh_1 c. For TYPE, select BOX d. For X0, enter -0.26, for Y0, enter -0.015, for Z0, enter -0.05 e. For DX, enter 0.5, for DY, enter 0.28, for DZ, enter 0.44 f. For NX, enter 50, for NY, enter 28, for NZ, enter 44 g. For Prop, select Euler h. Click Create i. Observe that Mesh_1 has been added

a b c d f

e

g

h i

CHAPTER 40 619 Multiple Bird-strikes on Box Structure

Create Mesh (continued) Creation of Mesh 2 (modeling Inside Box Euler) a. LBCs: Eulerian, select Mesh b. For Name: enter Mesh_2 c. For TYPE, select BOX d. For X0, enter -0.26, for Y0, enter -0.015, for Z0, enter -0.01 e. For DX, enter 0.5, for DY, enter 0.28, for DZ, enter 0.27 f. For NX, enter 50, for NY, enter 28, for NZ, enter 27 g. For Prop, select Euler h. Click Create i. Observe that Mesh_2 has been added j. In the Model Tree Browser, right click Mesh_1, select Show All

a

c

b d f

e

g i h j

620 MD Demonstration Problems CHAPTER 40

Create Cylinders Create Cylinder 1 a. LBCs: Couple, select Cylinder (not shown) b. From the Pick Window: select XYZ c. For X,Y,Z Coordinate, enter -0.1381 0.125 0.26; click OK d. For X,Y,Z Coordinate, enter -0.2381 0.125 0.26; click OK e. For ID: enter 1 f. For Name: enter Cylinder_1 g. For Radius, enter 0.035 h. Click Modify i. Observe that Cylinder_2 has been added

c b d

e

f g h

i

CHAPTER 40 621 Multiple Bird-strikes on Box Structure

Create Cylinders Create Cylinder 2 a. LBCs: Couple, select Cylinder (not shown) b. From the Pick Window: select XYZ c. For X,Y,Z Coordinate, enter 0.13 0.125 0.2252; click OK d. For X,Y,Z Coordinate, enter 0.17 0.125 0.2944; click OK e. For ID: enter 2 f. For Name: enter Cylinder_2 g. For Radius, enter 0.035 h. Click Modify i.Observe that Cylinder_2 has been added

c b d

e

f g i h

622 MD Demonstration Problems CHAPTER 40

Create Sphere (Initial Euler Condition) a. LBCs: Couple, select Cylinder, select Sphere (not shown) b. From the Pick Window: select XYZ c. For X,Y,Z Coordinate, enter 0 0 0; click OK d. For ID: enter 3 e. For Name: enter Sphere_3 f. For Radius, enter 1. g. Click Modify h. Observe that Sphere_3 has been added

b d

e f g

c

h

CHAPTER 40 623 Multiple Bird-strikes on Box Structure

Initial Euler Values Air initial values a. LBCs: TIC b. Click TICVAL c. For ID: enter 1 d. For Name: enter TICVAL_1 e. For Method, select NORMAL f. For Density, enter 1.1848 g. For SIE, enter 13880. h. Click Modify i. Observe that TICVAL_1 has been added

a b

c

e

d f

g h

i

624 MD Demonstration Problems CHAPTER 40

Initial Euler Values (Continued) Bird 1 initial values a. LBCs: TIC b. Click TICVAL c. For ID: enter 2 d. For Name: enter TICVAL_2 e. For Method, select NORMAL f. For XVEL, enter 200 g. Click Modify h. Observe that TICVAL_2 has been added

a b

c e

d f g

h

CHAPTER 40 625 Multiple Bird-strikes on Box Structure

Initial Euler Values (Continued) Bird 2 initial values a. LBCs: TIC b. Click TICVAL c. For ID: enter 2 d. For Name: enter TICVAL_2 e. For Method, select NORMAL f. For XVEL, enter -75. g. For ZVEL, enter -129.9 h. Click Modify i. Observe that TICVAL_3 has been added

a b

c e

d f

g h

i

626 MD Demonstration Problems CHAPTER 40

Initial Euler Regions Air initial region a. LBCs: TIC b. Click TICREG c. For ID: enter 1 d. For Name: enter TICREG_1 e. Double click VID f. In the Entity Selection window, select Sphere_3; click OK g. Double click MID h.In the Entity Selection window, select MATDEUL_3; click OK i. Double click TICID j. In the Entity Selection window, select TICVAL_1; click OK k. Click Modify l. Observe that TICREG_1 has been added

a b c

d e

g

i k

h f

j l

CHAPTER 40 627 Multiple Bird-strikes on Box Structure

Initial Euler Regions (Continued) Bird 1 initial region a. LBCs: TIC b. Click TICREG c. For ID: enter 2 d. For Name: enter TICREG_2 e. Double click VID f. In the Entity Selection window, select Cylinder_1; click OK g. Double click MID h.In the Entity Selection window, select MATDEUL_4; click OK i. Double click TICID j. In the Entity Selection window, select TICVAL_2; click OK k. Click Modify l. Observe that TICREG_2 has been added

a b c

d e

g

i k

f

h

j l

628 MD Demonstration Problems CHAPTER 40

Initial Euler Regions (Continued) Bird 2 initial region a. LBCs: TIC b. Click TICREG c. For ID: enter 3 d. For Name: enter TICREG_3 e. Double click VID f. In the Entity Selection window, select Cylinder_2; click OK g. Double click MID h.In the Entity Selection window, select MATDEUL_4; click OK i. Double click TICID j. In the Entity Selection window, select TICVAL_3; click OK k. Click Modify l. Observe that TICREG_3 has been added

a b c

d e

g

i k

f

h

j l

CHAPTER 40 629 Multiple Bird-strikes on Box Structure

Initial Euler Condition MESH_1 a. LBCs: TIC b. Click TICEUL1 c. For ID: enter 1 d. For Name: enter TICEUL1_1 e. For NREG, enter 3 f. Click Modify g. Observe that TICEUL1_1 has been added h. In the Model Browser tree, right click TICEU1L_1 i. Select Properties j. Double click TSID1 k. In the Entity Selection window, select TICREG_1; click OK l. Double click TSID2 m. In the Entity Selection window, select TICREG_2; click OK n. Double click TSID3 p. In the Entity Selection window, select TICREG_3; click OK q. Click Modify

a

d

c e

b

f

j l n h

i

p

k

m

o

630 MD Demonstration Problems CHAPTER 40

Initial Euler Condition MESH_2 a. LBCs: TIC b. Click TICEUL1 c. For ID: enter 2 d. For Name: enter TICEU1_2 e. For NREG, enter 1 f. Click Modify g. Observe that TICEUL1_2 has been added h. In the Model Browser tree, right click TICEUL1_2 i. Select Property j. Double click TSID1 k. In the Entity Selection window, select TICREG_1; click OK l. Click Modify

a

c e

b

d f

j l h

i k

CHAPTER 40 631 Multiple Bird-strikes on Box Structure

Initial Euler Properties MESH_1 a. Element properties: 3D b. Click PEULER1 c. For Name: enter PEULER1_3 d. For Type: select MMHYDRO e. Double click SID f. In the Entity Selection window, select TICEUL1_1; click OK g. Click Modify h. Observe that PEULER1_3 has been added

a

c e b d g f

632 MD Demonstration Problems CHAPTER 40

Initial Euler Properties MESH_2 a. Element Properties: 3D b. Click PEULER1 c. For Name: enter PEULER1_4 d. For Type: select MMHYDRO e. Double click SID f. In the Entity Selection window, select TICEUL1_2; click OK g. Click Create

a

c d

e g

b

f

CHAPTER 40 633 Multiple Bird-strikes on Box Structure

Add Euler Property to MESH_1 and MESH_2 a. Element Properties: 3D b. Select Properties c. Double click PID d. In the Entity Selection window, select PEULER1_3; click OK e. Click Modify f. In the Model Browser tree, right click Mesh_2 g. Select Properties h. Double click PID i. In the Entity Selection window, select PEULER1_4; click OK j. Click Modify

a d

b

c

e

f g

h

j

i

634 MD Demonstration Problems CHAPTER 40

Coupling Surfaces - Coupling Interaction Coupling Surface 1 a. LBCs: Couple, select COUPLE (not shown) b. From the Pick Window: select Shells for BSURF c. Select All; click Done d. For ID: enter 1 e. For Name: enter COUPLE_1 f. For COVER, select INSIDE g. For both REVERSE and CHECK, select On h. Double click MESHID i. In the Entity Selection window, select MESH_1; click OK j. Click Modify k. Observe that COUPLE_1 has been added

b

c d

e

g

f h

j

i

k

CHAPTER 40 635 Multiple Bird-strikes on Box Structure

Coupling Surfaces - Coupling Interaction (Continued) Coupling Surface 2 a. LBCs: Couple, select COUPLE (not shown) b. From the Pick Window: select Shells for BSURF c. Select All; click Done d. For ID: enter 2 e. For Name: enter COUPLE_2 f. For COVER, select OUTSIDE g. For both REVERSE and CHECK, select On h. Double click MESHID i. In the Entity Selection window, select MESH_2; click OK j. Click Modify k. Observe that COUPLE_2 has been added

b

c d

e

g

f h

j

i

k

636 MD Demonstration Problems CHAPTER 40

Coupling Surfaces - Coupling Interaction (Continued) Coupling interaction a. LBCs: Couple, select COUPINT (not shown) b. For ID: enter 1 c. For Name: enter COUPINT_1 d. Double click CID1 e. In the Entity Selection window, select COUPLE_1; click OK f. Double click CID2 g. In the Entity Selection window, select COUPLE_2; click OK h. Click Modify i. Observe that COUPINT_1 has been added

b d

c f h

e

g

i

CHAPTER 40 637 Multiple Bird-strikes on Box Structure

Parameters Define result frequency output a. Job Parameter: DYPARAM_BINARY_option b. For Name: enter DYPARAM_BINARY_option_1 c. For SID: enter 1 d. For DT_D3PLOT: enter 0.00015 e. Click Create f. Click Exit g. Observe that DYPARAM_BINARY_option_1 has been added

a c

b d

g e

f

638 MD Demonstration Problems CHAPTER 40

Parameters (Continued) Define initial time step a. Job Parameter: PARAM b. For Name: enter PARAM_2 c. For SID: enter 2 d. For N: enter DYINISTEP e. For V1: enter 5.E-7 f. Click Create g. Click Exit h. Observe that PARAM_2 has been added

a

b d

c e f

g

h

CHAPTER 40 639 Multiple Bird-strikes on Box Structure

Parameters (Continued) Define parameter to activate coupling interaction a. Job Parameter: DYPARAM b. For Name: enter DYPARAM_1 c. For SID: enter 2 d. For F1: enter FASTCOUP e. For F2: enter INPLANE f. For F3: enter FAIL g. Click Create h. Click Exit i. Observe that DYPARAM_1 has been added

a b d

c e

f g

h

i

640 MD Demonstration Problems CHAPTER 40

Create New Nastran Job a. In the Model Browser Tree, right click FileSet b. Select Create New Nastran Job

a

b

CHAPTER 40 641 Multiple Bird-strikes on Box Structure

Create New Nastran Job (Continued) Delete default Output Request to prevent excessive output Archive files a. In the Model Browser Tree: Simulations: NewJob: Load Cases; DefaultLoadCase: Output Requests: right click Displacement Output Request b. Click Delete c. Click Yes d. the Model Browser Tree: Simulations: Load Cases; DefaultLoadCase: Output Requests: right click Element Stress Output Request (not shown) e. Click Delete (not shown) f. Click Yes

a

b c

f

642 MD Demonstration Problems CHAPTER 40

Simulations Solver Control a. In the Model Browser Tree: Simulations: NewJob: Load Cases; Solver Control: right click Properties (not shown) b. Select Solution 700 Parameters c. Deactivate Large Displacement d. Deactivate Follower Forces e. Click Apply f. Click Close

a b c d e f

CHAPTER 40 643 Multiple Bird-strikes on Box Structure

Simulations (Continued) Define End Time and Output frequency for Loadcase Control a. In the Model Browser Tree: Simulations: NewJob: Load Cases; DefaultLoadCase: Loadcase Control right click Properties (not shown) b. Select Subcase Nonlinear Static Parameters c. For Ending Time: enter 0.0015 d. For Number of Time Steps: 10 e. Click Apply f. Click Close

b

c d

a

e f

644 MD Demonstration Problems CHAPTER 40

Simulations (Continued) Running New Nastran Job a. In the Model Browser Tree: right click NewJob b. Click Run

a

b

CHAPTER 40 645 Multiple Bird-strikes on Box Structure

Postprocessing Start SimXpert: New Project a. File: Attach Results b. File Path: select newjob.dytr.d3plot c. Attach Options, select Both d. Click Apply e. Repeat steps a through d for newjob.dytr_Euler_FV1_0.ARC (not shown) f. Repeat steps a through d for newjob.dytr_Euler_FV2_0.ARC

e

a

f

f b c

d

646 MD Demonstration Problems CHAPTER 40

Postprocessing (Continued) Displacement a. FileSet: Part: newjob b. Select Show Only c. Results: Deformation d. State plot property editor: Results cases: select Time 0.0015016 e. State plot property editor: Result type: click Deformation Components f. State plot property editor: click Deformation g. State plot property editor: Deformed Display scaling: select True h. Click Update

a

c

b f e

d

g

h

CHAPTER 40 647 Multiple Bird-strikes on Box Structure

Postprocessing (Continued) Fringe Stresses a. Results: Fringe b. State plot property editor: Results cases: select Time 0.0015016 c. State plot property editor: Results cases: select Stress Components d. State plot property editor: click Fringe e. State plot property editor: Element edge display: select Element edges f. Click Update

a

d

c b

e

f

648 MD Demonstration Problems CHAPTER 40

Postprocessing (Continued) IsoSurface Bird 1 (MESH_1) a. StatePlot: right click Deform 01 b. Select Hide c. StatePlot: right click Fringe 01 d. Select Hide e. FileSet: Part: right click NEWJOB.DYTR_EULER_FV1_0.ARC f. Select Show Only g. Results: Iso-Surface h. State plot property editor: Result cases: select ...FV1_cycle744 i. State plot property editor: Result type: select FMAT4 j. State plot property editor: click IsoSurface k. State plot property editor: Target entities: select All elements l. Click Update

a

e b

c f

d

g

j

h

k

i

l

CHAPTER 40 649 Multiple Bird-strikes on Box Structure

Postprocessing (Continued) IsoSurface Bird 2 (MESH_2) a. FileSet: Part: right click NEWJOB.DYTR_EULER_FV2_0.ARC b. Select Show Only c. Results: Iso-Surface d. State plot property editor: Plot attribute: select IsoSurf 02 e. State plot property editor: Result cases: select ...FV1_cycle744 f. State plot property editor: Result type: select FMAT4 g. State plot property editor: click IsoSurface h. State plot property editor: Target entities: select All elements i. Click Update

a c

b g d

f e

h

i

650 MD Demonstration Problems CHAPTER 40

Postprocessing (Continued) IsoSurfaces Deformations

CHAPTER 40 651 Multiple Bird-strikes on Box Structure

Results In this simulation, the time history of total z-force on the coupling surface is requested as shown in Figure 40-4. This force is the sum of all z-forces on the nodes that belong to both the upper and the lower plate. From Figure 40-4, it is obvious that there are three large impact forces occurring on the plate. The first one is when the first bird impacts the upper plate, which is subject to a significant damage. The second one is when the second bird impacts the upper plate. The last peak is caused by the first bird impacting the lower plate. Snapshots of the motion of the two birds and the deformation of the plates are shown in Figure 40-5 at various time steps of the simulation. Figure 40-5a is the initial condition. Figure 40-5b is at the moment when the first bird penetrates the upper plate and second bird touches the plate. This corresponds with the first peak in the time history plot shown in Figure 40-4. Figure 40-5c is at the moment when the second bird penetrates the upper plate. It corresponds with the second peak of the time history plot. Figure 40-5d is at the moment when the second bird has left the plate and the first bird penetrates the lower plate. This corresponds with the third peak in the time history plot.

Figure 40-4

Time History of Total Z-force on Coupling Surface

652 MD Demonstration Problems CHAPTER 40

Figure 40-5

Deformation of Plates

CHAPTER 40 653 Multiple Bird-strikes on Box Structure

Abbreviated SOL 700 Input File SOL 700,NLTRAN STOP=1 CEND TITLE = Multiple bird strike using Multi-Material-FVSurfer IC = 1 SPC = 1 TSTEPNL=1 $ BEGIN BULK PARAM*,DYINISTEP,1e-7 PARAM*,DYMINSTEP,1e-8 DYPARAM,FASTCOUP,INPLANE,FAIL DYPARAM,FMULTI,0.2 Dyparam,stepfctl,0.9 DYPARAM,LSDYNA,BINARY,D3PLOT,.00015 DYTIMHS,,.000001,,,,,,,+ +,CPLSOUT $ TSTEPNL, 1, 10, .00015, 1 $ $ Include model + SPC INCLUDE examp4_9_bs.bdf $ $ domain 1 $ MESH,1,BOX,,,,,,,+ +,-0.26,-0.015,-0.05,0.50,0.28,0.44,,,+ +,50,28,44,,,,EULER,1 $ $ COUPLING SURFACE 1 $ COUPLE, 1, INSIDE, ON, ON, , , , , + +, , , , , , , , , + +, 1 $ BSURF, 1, 7393, THRU, 8448, 13729, THRU, 14048, 14577, + +, THRU, 15236 $ $ Flow boundary, property, material and equation of state data. $ ------------------------------------------------------------FLOWDEF, 1, MMHYDRO, , , , , , + +, FLOW, OUT $ PEULER1, 1, , MMHYDRO, 11 PEULER1, 6, ,MMHYDRO, 12 EOSGAM,4,1.4 $ $--------Material Bird -----------------------------------MATDEUL, 3, 930, 3 EOSPOL, 3, 2.2e9 MATDEUL, 5, 930, 5 EOSPOL, 5, 2.2e9 $

654 MD Demonstration Problems CHAPTER 40

$============================================================= $ $ Allocation of material to geometric regions. $ -------------------------------------------TICEUL1 11 11 TICREG 1 11 CYLINDER1 3 1 3 TICREG 2 11 CYLINDER2 5 2 2 TICREG 3 11 SPHERE 4 4 5 1 $ CYLINDR 1 .13 .125 .2252 .17 .125 .2944 + .035 CYLINDR 2 -.1381 .125 .26 -.2381 .125 .26 + .035 SPHERE,4,,-.1381, .125, .26, 1000 $ $ Initial material data. $ ---------------------TICVAL 1 XVEL -75 ZVEL -129.9 TICVAL 2 XVEL 200 $ $ LAGRANGE $ $ Property, material and yield model. $ ----------------------------------PSHELL1 2 2 Blt Gauss 3 .83333 Mid + .0015 $ MATD024,2,4527,1.150e11,.314,1.38e8,,0.1 $ PSHELL,3,999,1.E-3 PSHELL,4,999,1.E-3 $ MATD009,999,1.E-20 $ $ Boundary constrain. $ -------------------CORD2C 1 0.0 0.0 0.0 0.0 0.25 0.0 + 0.0 0.125 0.25 $ $ -------- Material Air id =4 MATDEUL 4 1.1848 4 $ | $ -> density $ $-----------------------------Domain 2-----------------------------$ TICEUL1,12,12 TICREG,11,12,SPHERE,7,4,5,1.0 SPHERE,7,,0.0,0.0,0.0,500.0 TICVAL,5,,SIE,2.1388E5,DENSITY,1.1848 $ $===Coupling Surface 2 $ COUPLE,2,2,OUTSIDE,,,,,,+

+ +

+

+

CHAPTER 40 655 Multiple Bird-strikes on Box Structure

+,,,,,,,,,+ +,,2 $ BSURF 2 7393 THRU + THRU 15236 MESH,2,ADAPT,0.01,0.01,0.01,,,,+ +,-0.26,-0.015,-0.05,,,,,,+ +,,,,,,,EULER,6 $ $ coupling interaction $ COUPINT,2,2,1 $ ENDDATA

8448

13729

THRU

14048

Input File(s) File nug_40.dat

Description MD Nastran input file for multiple material Euler element using FSI technique

14577+