Abstract:
Direct numerical simulations based on three dimensional finite element
analysis were performed to investigate the mechanical behavior of knitted
textiles at the scale where their manufactured material architecture can
be simulated and assessed. A numerical investigation of the effects that
the material architecture has on deformation localizations, as well as
both in- and out-of-plane displacements is presented. To achieve this, a
procedure to numerically synthesize and modify knitted textile geometries
is investigated which takes into account yarn-to-yarn interactions, while
it further allows meshing used in finite element analyses. Appropriate
boundary conditions are applied to avoid unnecessary constraints, while a
specific type of interaction definition between yarn surfaces is enforced
to remove the effect of contact and friction. Furthermore nonlinear
analysis is used to capture the geometrically significant yarn position
changes resulting from the flexural motion of the looped knitted textiles.
The observed anisotropic effects are explained by examining the load
transfer as a function of local material architecture. In addition, both
linear and nonlinear material laws are used to study the role of material
nonlinearities in the mechanical behavior of this type of material at the
length scale of their architecture.
