Chapter 71: Impact of a Rigid on Composite Laminate using GENOA PFA Material

71Impact of a Rigid on Composite Laminate using GENOA PFA Material

Summary 1283

Introduction 1284

Requested Solution 1284

Model Details of Part 1 – Composite Shells 1284

Results 1285

Test versus Simulation 1286

Input File(s) 1286

Part 2 - Rigid Impact on Composite Foam Laminate using Genoa Material 1287

Model Details – Composite shells and Solid Foam Material 1287

Results of Part 2: 1288

Test versus Simulation 1288

Input File(s) 1288

1283CHAPTER 71

Impact of a Rigid on Composite Laminate using GENOA PFA Material

SummaryTitle Chapter 71: Impact of a Rigid Body on Composite Laminate using GENOA PFA

Material

Features Using Genoa composite shell material for impact simulation

Geometry

Material properties • Impactor (Rigid)Mass = 0.138 lbf-s2/inch = 53.2 lbmDiameter = 1 inch

• Plate (Deformable, GENOA 2D material) G30-500/45 R6367: /-45/0/90/0/90/0/90/0/90/-45/45Density = 1.962E-3 lbf-s2/inch412 layers (Details will be explained)

Analysis characteristics Transient explicit dynamic analysis (SOL700)

Boundary conditions Fixed boundary at sides of the plate

Applied loads Initial velocity of a rigid body

Element type 4-node shell element CQUAD4

FE results 1. Displacement and contact force time histories2. Stress Distribution plot at the end

Impactor Plate

MD Demonstration Problems

CHAPTER 711284

IntroductionMD Nastran predicts complex, large deformation composite behavior with extensive material degradation. GENOA PFA (Progressive Failure Analysis) material model available in MD Nastran SOL700 allows prediction of complex composite material behavior and degradation of the plies and laminates at micro-mechanical level. In the following example which includes two parts, the simulation results are compared and correlated closely to those of test results during a high velocity impact event. In part 1, the plate material is a composite laminate using shell elements while in part2, the plate material is a combination of laminate composites and solid foam material.

Requested SolutionThe displacement and contact force time histories are computed and compared with the test results.

Model Details of Part 1 – Composite ShellsThe 10-inch width by 11-inch length composite panel is sandwitched by two supporting plates during impact (Figure 71-1). The one-inch diameter impactor has a mass of 53.75 lbs with an impact velocity of 3.01 ft/sec resulting in a impact energy of 7.58 ft-lbs. The panel was made with six layers of G30-500/R3676 fabric (in which the fiber volume was 60 percent) with the ply lay-up of (45,-45), 4x(0,90),(45,-45). Each fabric ply is 0.014 inches thick and the total thickness of the panel is 0.084 inches. For details of the test results, please refer to the paper, “Impact, and Tension After Impact of Composite Launch Space Structure” (Frank Abdi, at al, Conference Paper 2001.).

Figure 71-1 Test and Simulation Setup

The composite shell panel is modeled using PCOMP entry. The panel has 12 layers and the thickness of each layer is 0.007 inch. The panel is made with the ply lay-up of (45,-45), 4x(0,90),(45,-45) which is the same as the test model.

PCOMP 1 + 1 .007 45.00000 1 .007 -45. + 1 .007 0.0 1 .007 90.00000

5.0 inch

5.0

inch

10.0 inch

11.0

0 in

chA A

Impactor Fixture plate

Impacted panel

1285CHAPTER 71

Impact of a Rigid on Composite Laminate using GENOA PFA Material

+ 1 .007 0.0 1 .007 90.00000 + 1 .007 90.00000 1 .007 0.0 + 1 .007 90.00000 1 .007 0.0 + 1 .007 -45. 1 .007 45.00000

The composite material is modeled using MAT1, MAT8, and MATM entries. MAT1 and MAT8 represent general isotropic and orthotropic material properties, respectively. Both materials are referred by MATM material where the fiber/ply and matrix properties of composite materials can be assigned. In addition, the failure criteria can also be defined in the MATM material model.

MAT1 333 560000.0 0.33 1.962E-3MATM 1 1 1 0 .6 0.0+ PLY 1 33 333000.0266000.0333000.0266000.0333000.0+ 266000.03846.0003846.0003846.000++ MATRIX 333 11000. 55000. 21000. 2.00E-02 .05 4.00E-02+ CRITICALS11T+ NONCRIT S11C S22C S33T S33C S12S S23S S13S+ MDE RROT CRSH DELM FMBK S22TMAT8 33 3.400E+72500000.0.2 2500000.2500000.1000000.1.962E-3

ResultsThe results of the simulation were compared with those of the test. MD Nastran SOL700 generates Lagrangian time history results into the binout binary and d3plot files while the Eulerian time history results are output in the THS file. The following displacement time history is generated using SimXpert reading the results from d3plot.

Figure 71-2 shows the displacement time history result at node 1 which is located in the center of the panel and shows the maximum displacement of 0.22 inches which correlates very closely to the maximum displacement from the test of 0.20 inches.

Figure 71-2 Displacement Time History at Node 1

MD Demonstration Problems

CHAPTER 711286

To generate the contact force time histories, an ASCII file is generated. This is because XY plots generation from binout binary file is not currently supported in SimXpert or Patran at this time. Alternatively, LS-Post can be used to generate the XY plot by reading the binout file directly.

To generate the ASCII file from binout file, a convertor tool called I2a is used. l2a is an executable that resides in the MD Nastran SOL 700 installation directories and reads in the binout binary file and generates an equivalent ASCII file. The command is:

l2a filename.dytr.binout0000After running this command, several ASCII files are generated that include nodal forces (ncforc), contact forces (rcforc), element forces (elout), etc.

In the rcforc file, the slave and master time history contact forces are recorded. The magnitude of contact forces on slave and master bodies are the same but with opposite signs. Using a contact force time history of the master contact body, the Figure 71-3 is generated by sorting the data first and then using MS xl for actual plot. The maximum z-contact force is 878.6 lbf compared to 897 lbf from the test results.

Figure 71-3 Contact Forces in Z-direction

Test versus Simulation

Input File(s)

Test Simulation

Maximum displacement (in) 0.20 0.22

Maximum contact force (lbf) 897 878.6

Files Description

E1-Impact.bdf MD Nastran input for composite shells

1287CHAPTER 71

Impact of a Rigid on Composite Laminate using GENOA PFA Material

Part 2 - Rigid Impact on Composite Foam Laminate using Genoa Material

Model Details – Composite shells and Solid Foam Material The 10-inch wide by 11-inch high panel was fully fixed at each side. The one-inch diameter impactor had mass of 53.75 lbs and impact velocity of 62.04 inch/sec. The panel was made with a composite foam, adhesive and skin composite fabric (Skin: G30-500/R3676, adhesive; FM-300, foam core: Rohacel 200WF.) The panel was laid up by skin, adhesive, foam core, adhesive and skin from the bottom surface. Each skin fabric ply is 0.014 inch thick and the total thickness of the skin ply is 0.056 inches (upper skin ply lay-up angle: -45, 45, 90, 0 and lower skin ply lay-up angle: 0, 90, 45, -45). The thickness of the FM300 adhesive layer is 0.01 inch and the thickness of the core foam is 0.37 inch. To get the test results, please refer the report, (Dade Huang, Frank Abdi, Mohsen Khatiblou “Progressive Failure Analysis (PFA) and Verification of Composite Test Panel Under Impact and Compression After Impact (CAI) Loading Using GENOA”. Alpha STAR Technical Report to Boeing 12/14/1999. Filename: 2-99_Report-impact_compression.)

The composite shell is modeled using PCOMP entry and the solid composite foam is modeled using PCOMPLS entry.

PCOMP 8+ 1 1.4E-02 0.00 1 1.4E-02 90.0+ 1 1.4E-02 45.0 1 1.4E-02 -45.PCOMPLS 6+ 1 2 1.0E-02 0.00+ 2 3 2.4E-02 0.00+ 3 3 2.4E-02 0.00+ 4 3 2.4E-02 0.00+ 5 3 2.4E-02 0.00+ 6 3 2.4E-02 0.00

To predict the progressive fracture, the material is modeled using MAT1, MAT8, and MATM entries. MAT1 and MAT8 represent general isotropic and orthotropic material properties, respectively. Both materials are referred by MATM material. The fiber/ply and matrix properties of composite materials and their failure criteria can be assigned by using the MATM entry shown below:

MAT1 333 560000.01 0.33 1.308-4MATM 1 1 0 .6 0.01+ PLY 1 33 333000. 266000. 333000. 266000. 333000.+ 266000.03846.0003846.0003846.0001.00E-021.00E-021.00E-02+ 1.00E-021.00E-021.00E-021.00E-021.00E-021.00E-02+ 0.03 0.03+ MATRIX 333 11000. 55000. 21000. 1.00E-02 .01 1.00E-02+ CRITICALS11T + NONCRIT S11C S22C S33T S33C S12S S23S S13S + MDE RROT CRSH DELM FMBK S22TMAT8 33 3.400E+72500000.0.2 2500000.2500000.1000000. 1.632-4

MD Demonstration Problems

CHAPTER 711288

Results of Part 2:The results of the simulation were compared with those of the test. To plot the results, same methodology as Part 1 was followed.

Figure 71-4 Contact Force Time History

The maximum z-contact force is 1510 lbf compared to 1514 lbf from the test results.

Test versus Simulation

Input File(s)

Test Simulation

Maximum contact force 1510 lbf 1514 lbf

Files Description

E2-Impact-Foam.bdf MD Nastran input for composite shells and solid foam material