Lightweight hybrid-construction sandwich structures

Transcription

1 26 th International SICOMP Conference Lightweight hybrid-construction sandwich structures Model identification and virtual testing L. Gigliotti S.T. Pinho Website:

2 Outline Lightweight: heavy impact Hybrid-construction sandwich structures Enabling faster structural design Conclusions Efficient

3 Lightweight: heavy impact

4 Composites share Lightweight: heavy impact 80% 50% 25% Parts produced

5 Outline Lightweight: heavy impact Hybrid-construction sandwich structures Enabling faster structural design Conclusions Efficient Macro/Meso cou

6 Hybrid-construction sandwich structures

7 Tied Foam Core technology Impact damage sensitivity Tied Foam Core Technology Stitching Manufacturability and performances T. Block, Analysis of the mechanical response of impact loaded composite sandwich structures with focus on foam core shear failure, PhD Thesis,

8 Tied Foam Core technology Unreinforced foam material TFC-reinforced foam material Relative increase [%] 60% 40% 20% 0% Mechanical properties +60% Strength +40% Stiffness Stitching angle 60% 40% 20% 0% Energy-absorption properties Increase in absorbed energy [%] Residual strain Residual strain Residual strain Stitching angle L.Gigliotti, S.T. Pinho, Energy-absorption properties of sandwich foam cores with TFC reinforcements, To be submitted.

9 Outline Lightweight: heavy impact Hybrid-construction sandwich structures Enabling faster structural design Conclusions Efficient

10 Time

11 Faster structural design

12 Faster structural design Post-crushing foam Solid-to-shell material model homogenization

13 Post-crushing foam Accuracy material model New proposed model Undamaged material models Faster structural design Sandwich structures damage-tolerance Solid-to-shell homogenization Post-crushing compressive response 1. Residual compressive strain 2. Residual compressive stiffness Post-crushing compressive response Modelling approaches Phenomenological models Testing time

14 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Model development Fitted monotonic compressive response Fully-crushed material compressive response Equilibrium between the crushed zone and the uncrushed zone L.Gigliotti, S.T. Pinho, Prediction of the post-crushing compressive response of progressively crushable sandwich foam cores, To be submitted.

15 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Model validation Thickness of the crushed layer 13% Max Error L.Gigliotti, S.T. Pinho, Prediction of the post-crushing compressive response of progressively crushable sandwich foam cores, To be submitted.

16 Post-crushing foam material model Faster structural design Residual strain after-crushing Residual strain Solid-to-shell homogenization Error Reduction (%) Error reduction Error reduction over 56% Crushing strain Crushing strain L.Gigliotti, S.T. Pinho, Prediction of the post-crushing compressive response of progressively crushable sandwich foam cores, To be submitted.

17 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Model validation Post-crushing compressive response L.Gigliotti, S.T. Pinho, Prediction of the post-crushing compressive response of progressively crushable sandwich foam cores, To be submitted.

18 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Predictive model for a faster characterization of foam materials L.Gigliotti, S.T. Pinho, Prediction of the post-crushing compressive response of progressively crushable sandwich foam cores, To be submitted.

19 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Solid-to-shell homogenization Periodic Structures 3D deformable body Solid-to-shell Equivalent shell model homogenization L.Gigliotti, S.T. Pinho, Exploiting symmetries in solid-to-shell homogenization, with application to periodic pin-reinforced sandwich structures, Submitted to Compos. Struct.

20 Post-crushing foam material model Faster structural design Periodic Boundary Condition (PBS) Solid-to-shell homogenization Unit Cells vs reduced Unit Cells UC ruc Only one quarter of the Unit Cell needs to be modelled 100% CPU time 75% 50% 25% 0% CPU time reduction -85% Modelling time CPU time 100% 75% 50% 25% 0% -89% Analysis time UC ruc UC ruc L.Gigliotti, S.T. Pinho, Exploiting symmetries in solid-to-shell homogenization, with application to periodic pin-reinforced sandwich structures, Submitted to Compos. Struct.

21 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Exploit symmetries for a faster computation of equivalent properties L.Gigliotti, S.T. Pinho, Exploiting symmetries in solid-to-shell homogenization, with application to periodic pin-reinforced sandwich structures, Submitted to Compos. Struct.

22 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Multiple length-scales Local/global Coupling 1. Suitable coupling technique between different length-scales 2. Minimize the area modelled at the smallest length-scale L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

23 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Mesh Superposition Technique (MST) Meshes overlap at the transition between differently-discretized subdomain L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

24 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Validation Interlaminar damage pattern prediction L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

25 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Validation Interlaminar damage pattern prediction L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

26 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Fully Local model Sudden Transition model L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

27 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Fully Local model MST model L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

28 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Damage pattern Fully Local model Damage pattern Multiscale models Fully Local 0 Sudden Tr. MST ± L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

29 Post-crushing foam material model Computational time comparison Normalized CPU time Faster structural design Solid-to-shell homogenization Fully Local Computational Advantages -60% Area Local model -23% CPU time Normalized area Local model Normalized area Local model Normalized CPU time L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

30 Faster structural design Post-crushing foam Solid-to-shell material model homogenization Multiscale approach for a faster simulation of localized damage in composite structures L.Gigliotti, S.T. Pinho, Multiple length/time-scale simulation of localized damage in composite structures using a Mesh Superposition Technique, 2015, Compos. Struct. (121)

31 Outline Lightweight: heavy impact Hybrid-construction sandwich structures Enabling faster structural design Conclusions Efficient

32 Conclusions

33 Conclusions Tied Foam Core technology Predictive model for the post-crushing response of sandwich foam cores Exploit symmetries in solid-to-shell homogenization Efficient with localized damage

34 26 th International SICOMP Conference Lightweight hybrid-construction sandwich structures Model identification and virtual testing L. Gigliotti S.T. Pinho Website: