Modeling of Prepregs during Automated Draping Sequences

Christian Krogh, Jens Ammitzbøll Glud, Johnny Jakobsen

Publikation: Konferencebidrag uden forlag/tidsskriftPosterForskning


Composite parts made from pre-impregnated fiber mats, so-called prepregs,
are frequently used in the aerospace industry due to their superior mechanical
properties. Currently, woven prepregs are manually placed into a mold prior
to curing. The manual layup process is costly and can yield significant quality
variations in the final part. Thus, an automated layup solution is under
development where a robot can manipulate and drape the prepregs into the
The success of this implementation relies on both accurate and computationally
efficient models describing the mechanical behavior of the prepreg
material which is the scope of the PhD project. The models will aid in
generating feasible robot trajectories, i.e. draping sequences. Here feasible
entails that the fiber plies do not deform undesirably while being manipulated
by the robot as well as drapes onto the mold without wrinkles, air pockets and
other defects. The models must, among other things, account for the nonlinear
anisotropic constitutive behavior, viscoelasticity, possible plasticity,
and contact which includes friction between the ply-mold and ply-end effector
interfaces. The problem is path dependent and thus the transient aspect of the
draping must be taken into account.
The accurate modeling is accomplished with an explicit Finite Element (FE)
scheme with shell elements. Material characterization in the form of uniaxial
tensile tests, bias-extension tests (45 ° tensile test) and bending tests provide
input for the model. With basis in an experimentally validated FE model and
with improved knowledge of the mechanics of the plies, more efficient
models and/or simple wrinkling criteria are to be developed at a later stage.
Publikationsdato15 mar. 2017
StatusUdgivet - 15 mar. 2017
Begivenhed16th Internal DCAMM Symposium - Hotel Comwell, Middelfart, Danmark
Varighed: 13 mar. 201715 mar. 2017


Konference16th Internal DCAMM Symposium
LokationHotel Comwell


  • Mekanik
  • matematik