6. Solution and Post-Processing

Transcription

1 Lesson 6 1. Introduction to Laminate Composite Simulation 2. Zone-Based Process 3. Ply-Based Process 4. Modeling 3D Laminates 5. Materials and Micromechanics 6. Solution and Post-Processing 7. Laminate Theory 8. Laminate Failure Analysis 9. Laminate Dynamic Simulation 10. Laminate Optimization Activities: Structural Analysis of Thick Laminated Support Post reporting using mudguard solution Page 1

2 Nastran solver properties- Laminate Exported as NSM on the PCOMP, PCOMPG, or PSHELL cards. Exported as GE on the PCOMP or PCOMPG cards. If selected, SOUT is exported as YES on the PCOMP or PCOMPG card Provide special purpose stiffness calculation for PCOMP and PCOMPG cards. You can export the 2D laminate as a PCOMP, PCOMPG, or PSHELL card. Page 2

3 Nastran solver properties -Laminate Page 3

4 Nastran solver properties - Laminate Page 4

5 What s the Difference between PCOMP and PCOMPG? Ply ply global layup Ply 101 Ply 103 Page 5

6 Ply Stresses - PCOMPG Ply 100 Ply 101 Ply 103 Page 6

7 Ply Stresses - PCOMP Ply 1 Ply 2 Ply 4 Page 7

8 Nastran solver properties - Laminate Nastran internally converts the PCOMP and PCOMPG cards, along with the associated material cards, to an equivalent PSHELL card with up to 4 anisotropic MAT2 material cards. Each MAT2 card represents a different behavior, depending on the PSHELL MID that references it: MID1: Membrane MID2: Bending MID3: Transverse Shear MID4: Membrane-bending Coupling Page 8

9 Nastran laminate export options for PCOMP, PCOMPG and PSHELL cards Laminate Option None with Symmetric stacking recipe None with other stacking recipes NASTRAN Definition Only plies on one side of the mid plane are specified on the PCOMP card. Does not apply for the PCOMPG card. All the plies are specified on the PCOMP or PCOMPG cards. MEM Only membrane terms are retained. Intended for SOL 200. BEND Only bending terms are retained. Intended for SOL 200. SMEAR SMCORE with Symmetric with Core SMCORE + transverse shear with Symmetric with Core Stacking sequence is ignored, shear and bending-membrane coupling terms are set to 0. Intended for SOL 200. Stacking sequence is ignored, shear and bending-membrane coupling terms are set to 0. Intended for SOL 200. For a sandwich, provides a PSHELL equivalent that includes membrane, bending and transverse shear stiffness for which the extreme fiber stresses (top of top ply and bottom of bottom ply) will be accurate. For all solutions. Page 9

10 SMCORE + Transverse Shear PSHELL representation of symmetric sandwich that allows for accurate recovery of maximum and minimum isotropic facesheet stresses Includes the following stiffness components: Membrane Bending (smeared facesheet representation) Transverse Shear The simple PSHELL representation will not provide accurate stresses Page 10

11 SMCORE + Transverse Shear - Max Stresses at Z0 (Bottom of Ply 1) PCOMP PSHELL Page 11 SMCORE+Tranverse Shear

12 Nastran solver properties - Laminate Output Request SOUT For the 2D laminate property, SOUT specifies whether or not the results are written as text to the.f06 file. The results are always written to the.op2 file. Page 12

13 Nastran solver properties- Solid Laminate Exported as GE on the PCOMPS card. If selected, SOUT is exported as YES on the PCOMPS card You can export the 3D laminate as a PCOMPS or a homogeneous PSOLID card. Page 16

14 Nastran solver properties Solid Laminate Output Request SOUT For the 3D solid laminate property, SOUT specifies whether or not the results are written to the op2 file. Different behavior than for 2D laminates If you want results in NX Post, you must check this option. It is checked by default in the solid laminate modeler dialog. Page 17

15 NX Nastran solver properties Solid Laminate Page 18

16 NX Nastran solver properties - Solid Laminate Page 19

17 Homogeneous Properties for 3D Laminates Selectively replace PCOMPS by PSOLID At the laminate/layup level At the individual ply level Benefit: faster solution time, fewer results Equivalent 3D orthotropic material properties are computed on-the-fly Valid for symmetric and balanced layups The further away the layup is from this condition, the poorer the homogeneous representation will be. Works for NX Nastran, ANSYS and ABAQUS Page 20

18 Nastran laminate results Output Request Force Stress/Strain Output Format PCOMP / PCOMPG/ PSHELL PSOLID/PCOMPS (NX) PCOMP / PCOMPG PCOMP / PCOMPG/ PSHELL/PSOLID PCOMPS (NX only) Output Result Shell stress resultants Solid element forces Ply stresses and strains Ply and bond failure indices Ply and bond strength ratios Element stresses Element strains Ply stresses and strains Failure indices Strength ratios Page 21

19 Nastran solutions that support ply results Linear statics 101 Normal modes 103 Buckling 105 Nonlinear Direct transient response 109 Modal transient response 112 Cyclic statics 114 Nonlinear transient response Design optimization 200 Advanced nonlinear 601 Note 1. Not available for large displacement analysis Page 22

20 NX Post Native coordinate system Native Coordinate System Native means that the result in the op2, rst, fil or odb file is presented by NX Post without transformation of the solver result. Page 23

21 Nastran laminate results Results Coordinate Systems in NX Post By default, shell stress resultants are displayed in the native (element) coordinate system. DMAP can be used to force storage in the material system Ply stress and ply strain results are displayed in the native (ply) coordinate system. Interlaminar ply stress and strain results are displayed in the: Native (material) coordinate system for 2D elements. Hence the core ribbon direction should be the material direction! Native (ply) coordinate system for 3D elements. Page 24

22 Nastran laminate results Results Locations in NX Post Ply results are at: The middle of the ply for 2D elements Where selected, for 3D elements Interlaminar results are at: The top of the ply for 2D elements The top and bottom of the ply (as requested) for 3D elements Page 25

23 Nastran laminate results Elemental/Nodal Output in NX Post 2D element ply results are at the element centroid only. Elemental in NX Post 3D element results are as selected Elemental in NX Post Element-Nodal in NX Post Page 26

24 Nastran laminate results Strength Ratios To turn on the computation of Nastran strength ratios, you must edit your solution and add the following PARAM: Page 27

25 Shell stress resultant notations NX Laminate Composites Nastran ABAQUS ANSYS NX Post Processing Nx Fx SF1 N11 Nxx Ny Fy SF2 N22 Nyy Nxy Fxy SF3 N12 Nxy Mx (-Mx wrt Nastran) Mx SM1 M11 Mxx My (-My wrt Nastran) My SM2 M22 Myy Mxy (-Mxy wrt Nastran) Mxy SM3 M12 Mxy Qx Qy Vx Vy SF5 SF4 Q13 Q23 Qxz Qyz Page 30

26 Nastran shell stress resultant convention The Nastran convention, shown in the following graphics, differs from the convention used by NX Laminate Composites in that the signs of the moments per unit length Mx, My, and Mxy are reversed. Nastran force convention Nastran moment convention Page 31

27 Activity: Structural analysis of a thick laminated support In this activity, you will: Create a laminate physical property. Use the Extrude Laminate command to inflate a 2D mesh with a laminate physical property definition. Solve and display results in the postprocessing navigator Page 32

28 View Laminate Post Processing A sketch of the laminate with the number of plies and total thickness. Ply layup information that includes the global ply ID, the material composition, thickness, and angle of the ply. The minimum and maximum values of the selected results and the ply ID where the extrema occur Page 33

29 NXLC Advanced post reporting of laminate results Use the Advanced Post Report command to quickly identify critical element and ply data over many solutions. The enveloping, filtering, and sorting tools help you to find the critical element and ply data that you want without reviewing all the solver ply data. The command reads results from Nastran, ANSYS, or Abaqus, and computes: Ply stresses and strains (2D) Ply and bond failure indices Ply and bond margins of safety Ply and bond strength ratios Page 34

30 Solver 2D results from solvers and laminate post reporting Solution Shell Stress Resultants Ply Stresses Ply Strains Ply Stresses Ply Strains Ply failure indices, strength ratios & margins of safety NXLC Post Reporting Ply failure indices & strength ratios Laminate post reporting reads the shell stress resultants from the structural Solver, calculates ply stresses and strains and failure indices, strength ratios and margins of safety Laminate post reporting reads ply stresses and strains from the structural solver and calculates failure indices, strength ratios and margins of safety Page 35

31 Solver 3D results from solvers and laminate post reporting Solution Ply Stresses Ply Strains Ply failure indices, strength ratios & margins of safety NXLC Post Reporting Ply failure indices & strength ratios Laminate post reporting reads ply stresses and strains from the structural solver and calculates failure indices, strength ratios and margins of safety Page 36

32 Advanced post processing of laminate results Spreadsheet and graphical post reports use the laminate properties in your active FEM. This allows you to switch failure theories or even modify your laminates after the solution was solved to perform what-if analyses without re-solving. It also allows you to validate your laminates using failure theories that are not supported by the solver, including user-defined failure theories Post report currently computes elemental results only. NX automatically updates draping and zones if required, prior to accessing results. The quick post report queries the results without accessing the FEM. Page 37

33 Laminate spreadsheet report The laminate spreadsheet report contains reports on the following laminate results: The shell stress resultants. The specific components of ply stress and strain results. The failure indices, strength ratios, and margins of safety. You can output filtered and sorted ply results in laminate spreadsheet reports. Page 38

34 Laminate spreadsheet summary tables The spreadsheet that is generated by the spreadsheet report or the quick report contains: A top summary table that lists the worst ply values for all the result sets and structural data input selection. A summary table for each result set and for each structural data input selection. For each of the requested results, the summary tables display: The location where the critical value occurs. The critical value in blue. The value of the other quantities at the same location. Page 39

35 Laminate spreadsheet summary tables Layer/Ply Name of laminate ppt Failure theory - bond Element Location Failure theory - ply Selected results & components Page 40

36 Laminate graphical report The laminate graphical report generates laminate results contours that you can display from the Post Processing Navigator. These results are stored in a binary file in the current directory. The laminate graphical report outputs the following laminate results: Ply stress and strain. Ply failure indices, strength ratios, and margins of safety. Page 41

37 Laminate graphical report Results are first enveloped over solutions, and then over all selected plies Ply results enveloped over all solutions Elemental results enveloped over all solutions and over all plies Page 42

38 Laminate graphical report Use the Show Critical Ply ID option of Post View to display the ID of the critical ply for the elemental, ply-enveloped results. Page 43

39 Laminate graphical report Use the Show Critical Load Case option of Post View to display the ID of the critical load case for the elemental, ply-enveloped results. Page 44

40 Laminate graphical /spreadsheet reports Results Source You can set the solver shell stress resultants or the solver ply stresses and strains as the input to the laminate solver. Results Location When using the shell stress resultants as the input, you can select any combination of bottom, middle, and top locations for the ply stress/strain calculation. Results Coordinate System Results can be computed in the ply or the laminate coordinate systems. The laminate coordinate system option can only be used when the results source is shell stress resultants. Page 45

41 Laminate graphical /spreadsheet reports Computation Domain You can also request the data on selected elements and plies. Page 46

42 Laminate quick report The laminate quick report exports the results summaries to an Excel spreadsheet or a CSV file without querying the active FEM. The quick report contains: A top summary table that lists the worst ply values for all the result sets. A summary table for each result set. Page 47

43 NX Post Results Manipulation The NX Post results manipulation tools are capable of processing ply results Page 48

44 Activity: Structural analysis of a satellite antenna In this activity, you will: Create a simulation file with a Nastran or ANSYS solution. Use the View Laminate command Export ply results to a spreadsheet and a quick report. Create a graphical post report and identify the critical plies Page 49

45 Review questions True/False. NX Laminate Composites can post process the results from Nastran, Abaqus, ANSYS, and LS-DYNA. True/False. Spreadsheet and graphical post reports query the active FEM. True/False. Spreadsheet and graphical post reports can filter and sort results. Page 50

46 Answers to review questions 1. True/False. NX Laminate Composites can post process the results from Nastran, Abaqus, ANSYS, and LS-DYNA. False. You can only write out the LS-DYNA solver input file. NX does not support LS-DYNA solver and cannot post process LS-DYNA results. 2. True/False. Spreadsheet and graphical post reports query the active FEM. True. Spreadsheet and graphical post reports use the laminate properties in your active FEM, so that you can switch failure theories and even modify your laminates after the solution was solved to perform what-if analyses. The laminate quick report exports the results summaries to an Excel spreadsheet or a CSV file without querying the active FEM. 3. True/False. Spreadsheet and graphical post reports can filter and sort results. False. You can sort and filter the laminate results only with the spreadsheet report. Page 51