Implementation of a Simulation Tool of Strains Induced During the Co-bonding of Autoclave-cured Parts

Abstract : Our on-going research focusses upon composite structural parts such as stiffened panels with co-bonded stringers. This study is aiming to developing a numerical tool based on commercial softwares (e.g. Abaqus ® and Fortran ®) enabling after-cure deformations to be predicted for co-bonded composite parts. Several simulations moduli were developed to describe i the thermochemical, ii the thermomechanical behaviours of prepreg plies and structural adhesive film and iii the mould/part interaction. An experimental work was conducted in parallel in order to get firstly simulation input parameters (i.e. material behaviour laws) and secondly experimental deformations on co-bonded composite specimen. The materials used were the Hexcel U.D. prepreg tape M21EV/IMA and the Cytec FM300M structural adhesive film. During a first step (first cure cycle), the process-induced strains of the laminated panel that will be stiffened with stringers were computed and compared to experimental ones. During the second step (second cure cycle) the process-induced strains and deformation were computed on the cured laminate but also on the stringer foot and on the structural adhesive as shown in Fig. 1. Lastly comparing experimental results to simulations shows clearly the interest of considering a 2 steps manufacturing process with 2 cure cycles instead of a single one in which all the components (i.e. panel, adhesive and stringer foot) are cured together.