1. Local Strain Development of the Wood-Matrix Matthew J. Schwarzkopf Xiang Lin
Lech Muszynski John A. Nairn
Interphase in Wood-Plastic Composites Farzana Hussain
Introduction Short Fiber Composite Theory Future Work
Mechanical properties of wood plastic Effective load transfer
-Fibers are identical in shape is limited to the 3D modeling
Tensile
stress
composites are determined by the load and size bonded length of the The strain fields present represent the
transfer between the wood particle and fiber surface of the test specimen.
-Fibers and matrix are well The particle is actually located some
the matrix. The strength of the internal Bonded length of the fiber
Residual load transfer
distance below the surface. 3D
bonded at their interface through friction
bond determines whether the particles act modeling is required to resolve the
stress
Shear
throughout deformation in the de-bonded
as merely filler or as reinforcement. segments of the fiber strain field offset.
http://urbana.mie.uc.edu/yliu/Im
ages/short_fiber_composites.jpg
Assumptions previously made for short Materials and Methods Results Single Particle Strain Measurements
fiber theory cannot be applied to wood
Wood particles used in wood
plastic composites because the particles plastic composites are :
are porous, permeable and irregular. • Irregular
• Porous Direct strain
• Anisotropic measurements will
Objective • Non-homogeneous be taken on single
• Does the SFC theory apply?
Characterize the full-field deformation and Hussain (2009)
particles
strain distribution in and around wood Uniform geometry wire Wood Particle embedded Multiple Particle Interactions
particles embedded in
flour particles embedded in a polymer HDPE as reference
in HDPE
matrix experimentally.
Wood
Plastic
Composite
WPCs loading rates vary depending
Decking Tensile Testing on the desired product. When the
Material wood particle load is increased,
particle-particle interactions occur
Wood particle -High strain concentration -Higher strain levels present
present at fiber ends at fiber ends Acknowledgements
-Load is transferred along -Load transfer is limited to
the majority of the fiber the center portion of the
Wire particle (reference)
http://www.appropedia.org/File:Wood_Plastic_Composite.jpg fiber