laminate stacking sequences Nomie Fedon Terence Macquart, Paul - PowerPoint PPT Presentation

Optimisation of composite laminate stacking sequences Noémie Fedon Terence Macquart, Paul Weaver, Alberto Pirrera CDT conference 16 April 2019

2 Design of blended composite laminates Aims Difficulties • Highly non-linear and non-convex objective and constraints functions • Many design variables [ ϴ 1 , ϴ 2 , ϴ 3 , ϴ 4 ] • Discrete design variables • Discrepancy in the multi-level optimisation Lightweight structures Noémie Fedon Optimisation of composite laminate stacking sequences

3 Novel optimiser to design the plies’ fibre orientations ξ 3 Target lamination parameters 0° 45° 90° -45° ξ 1 0° 45° 90° -45° Boundary of the lamination 0° 45° 90° -45° parameter 0° 45° 90° -45° design space [45, 90, - 45, ?, …, ?] Noémie Fedon Optimisation of composite laminate stacking sequences

4 Design of a benchmark 18-panel structure 18 in. 20 in. 12 in. N x = -270 N x = -250 N x = -210 N y = -325 N y = -200 N y = -100 24 in. N x = -700 N x = -375 N y = -400 N y = -360 N x = -305 N x = -290 N x = -600 N y = -360 N y = -195 N y = -480 N x = -1100 N x = -900 N y = -600 N y = -400 Load intensities in lbf/in (x 1751.1 for N/m) N x = -330 N x = -190 N x = -300 N y = -330 N y = -205 N y = -610 N x = -375 N x = -400 N y = -525 N y = -320 N x = -815 N x = -320 N x = -300 N y = -1000 N y = -180 N y = -410 • • Execution time: 10 min Weight: 28.8 kg Noémie Fedon Optimisation of composite laminate stacking sequences

5 Conclusion and future work • Multi-level optimisation to account for load redistribution 1 - stiffness and thickness optimisation 2 - stacking sequence design Ply counts Thickness in mm Upper skin Lower skin Interaction between the levels of optimisation Noémie Fedon Optimisation of composite laminate stacking sequences

Design of blended composite laminate structures noemie.fedon@bristol.ac.uk

7 Novel technique to design blended structures Sub-division of the optimisation problem 0° 45° 90° -45° 0° 45° 90° -45° Group 1 0° 45° 90° -45° 0° 45° 90° -45° Group 2 Group 3 0° 45° 90° -45° 0° 45° 90° -45° Panel 1 Panel 3 Panel 4 Panel 2 0° 45° 90° -45° 0° 45° 90° -45° 0° 45° 90° -45° 0° 45° 90° -45° 0° 45° 90° -45° 0° 45° 90° -45° Noémie Fedon Optimisation of composite laminate stacking sequences

8 Design of a benchmark 18-panel structure Method Results 18 in. 20 in. • Initial thickness Weight similar than in 12 in. N x = -270 N x = -250 N x = -210 distribution from the literature N y = -325 N y = -200 N y = -100 24 in. N x = -700 N x = -375 individual panel N y = -400 N y = -360 N x = -305 N x = -290 N x = -600 N y = -360 N y = -195 N y = -480 optimisations • Design obtained less than an hour N x = -1100 N x = -900 N y = -600 N y = -400 Multi-panel structure • Many laminate design Load intensities in lbf/in (x 1751.1 for N/m) optimisation guidelines can be N x = -330 N x = -190 N x = -300 considered: symmetry, N y = -330 N y = -205 N y = -610 N x = -375 N x = -400 balance, contiguity, Addition of a ply to N y = -525 N y = -320 N x = -815 N x = -320 N x = -300 disorientation, 10% the most critical N y = -1000 N y = -180 N y = -410 rule, ply drop spacing panel if the buckling and stacking constraints are not all satisfied Noémie Fedon Optimisation of composite laminate stacking sequences

9 Design of composite laminates M N = Number of possible Objective For single-panel stacking sequences optimisation with a fixed number of plies • Highly non-convex objective function • Discrete design variables [ ϴ 1 , ϴ 2 , ϴ 3 , ϴ 4 ] N = Number of plies • Many design variables • Many design and manufacturing guidelines Lightweight structures Noémie Fedon Optimisation of composite laminate stacking sequences