Investigation of thermally induced bistable behaviour for tow-steered laminates

Abstract Traditionally, bistable laminates have been developed from prepreg plies stacked up together to achieve a layup which is either constant or discretely varying over the planform of the laminate. Laminates with discrete variation in layup are, in particular, of interest as they offer the prospect of easier blending. Moreover, such laminates can be manufactured to have Variable Angle Tows (VATs) in a ply using a tow-steering technique, doing so, ensures fibre-continuity and may impart additional structural strength. This paper presents an approach to develop finite element (FE) models which can accurately predict the cured shape(s) of tow-steered laminates that are designed to be bistable. Manufactured laminates are characterised using microscopy and resin burn-off tests to identify resin-rich layers, ply-thicknesses and fibre volume fractions ( V f ) – which are then translated into FE models. Presented data highlights the influence of the manufacturing process in the thermally induced bistable behaviour of tow-steered laminates.

[1]  Michael R Wisnom,et al.  Loss of bifurcation and multiple shapes of thin [0/90] unsymmetric composite plates subject to thermal stress , 2004 .

[2]  Z. Gürdal,et al.  Variable-stiffness composite panels: Buckling and first-ply failure improvements over straight-fibre laminates , 2008 .

[3]  Kevin D Potter,et al.  Sources of variability in uncured aerospace grade unidirectional carbon fibre epoxy preimpregnate , 2007 .

[4]  Michael W. Hyer,et al.  Some Observations on the Cured Shape of Thin Unsymmetric Laminates , 1981 .

[5]  Keith A. Seffen,et al.  Multistable corrugated shells , 2008, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[6]  Kevin D Potter,et al.  The internal structure and conformation of prepreg with respect to reliable automated processing , 2011 .

[7]  Sergio Pellegrino.  Bistable Shell Structures , 2005 .

[8]  F Mattioni.  Thermally induced multi-stable composites for morphing aircraft applications , 2009 .

[9]  Michael W. Hyer,et al.  Thermally-induced deformation behavior of unsymmetric laminates , 1998 .

[10]  Paul M. Weaver,et al.  Characterization of Unsymmetric Cross -Ply Laminate Deflections Using Orthogonal Polynomials , 2008 .

[11]  Lee,et al.  [American Institute of Aeronautics and Astronautics 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference - Austin, Texas ()] 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference - Aeroelastic Studies on a Folding Wing Configuration , 2005 .

[12]  Derek Bye,et al.  Design of a Morphing Vehicle , 2007 .

[13]  Paul M. Weaver,et al.  Concepts for morphing airfoil sections using bi-stable laminated composite structures , 2008 .

[14]  Lothar Kroll,et al.  Design of multistable composites for application in adaptive structures , 2002 .

[15]  Michael W. Hyer,et al.  Calculations of the Room-Temperature Shapes of Unsymmetric Laminatestwo , 1981 .

[16]  Paul M. Weaver,et al.  Bistable prestressed buckled laminates , 2008 .

[17]  Paul M. Weaver,et al.  Optimization of Blended Bistable Laminate for Morphing Flap , 2010 .

[18]  M. W. Hyer,et al.  Non-linear temperature-curvature relationships for unsymmetric graphite-epoxy laminates , 1987 .

[19]  Brian Tatting,et al.  Tow-Placement Technology and Fabrication Issues for Laminated Composite Structures , 2005 .

[20]  Michael W. Hyer,et al.  Advanced calculation of the room-temperature shapes of thin unsymmetric composite laminates , 1995 .

[21]  Ian P Bond,et al.  48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Honolulu, Hawaii, USA , 2007 .

[22]  Kevin D Potter,et al.  50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference , 2009 .

[23]  Phil Mellor,et al.  On a Bistable Flap for an Airfoil , 2009 .

[24]  Christopher R. Bowen,et al.  Bistable composite laminates: Effects of laminate composition on cured shape and response to thermal load , 2010 .

[25]  Christopher R. Bowen,et al.  A Study of Bistable Laminates of Generic Lay‐Up for Adaptive Structures , 2012 .

[26]  Paul M. Weaver,et al.  Thermally induced bi-stable morphing composites using tow-steering , 2009 .

[27]  Christopher R. Bowen,et al.  Characterisation and modelling of the cured shapes of arbitrary layup bistable composite laminates , 2010 .

[28]  Ajit Panesar,et al.  51st AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference, Orlando, Florida , 2010 .

[29]  Dawn C. Jegley,et al.  Design and Manufacture of Elastically Tailored Tow Placed Plates , 2002 .

[30]  Paul M. Weaver,et al.  Environmental effects on thermally induced multistability in unsymmetric composite laminates , 2009 .