Dimensional Scaling and Failure Pattern of the Tensile Properties of Angle-Ply Thermoplastic Composites of Twaron Fiber/Polypropylene

作者：Martin Barrera Cesa; Soberanis Monforte Genaro A; Gonzalez Chi Pedro I^*

来源：Frontiers in Materials, 2018, 5: 36.

DOI：10.3389/fmats.2018.00036

• thermoplastic composite
• scaling effect
• balanced nonsymmetrical laminates
• multilayered composite
• fracture characterization

Thermoplastic multilayer composites with different fiber orientations were prepared with polypropylene and aramid fibers as reinforcing material. The prepregs were prepared in a continuous impregnation system using the dry powder method in a fluidized bed. The specimens were laminated by compression molding, tensile tested, and their fracture area was analyzed by microscopy. The mechanical performance of the laminates was influenced by the fiber orientation at the different layers. The fibers at 0 degrees conferred high stiffness to the composite, limiting the maximum deformation and promoting failure. The laminates with 0 degrees layers showed a fragile and sudden fracture oriented at 90 degrees to the aplied load, even with low fiber content. The plies oriented at +/- 45 degrees balanced the stress and contributed to higher levels of deformation during the test due to fiber rotation toward the loading direction, also, no post-yield stiffening was found as in thermoset composites due to the ductile nature of the thermoplastic matrix; these layers limited the crack propagation in the transverse direction, canceling the in-plane shear stress. The fibers at 90 degrees acted as filler due to poor interface and did not contribute tothe improvement of the composite mechanical performance. The evidence shows no delamination in the materials due to the tenacious nature of the thermoplastic matrix, neither saw-toothed or plateau region was found in the stress-strain curves in contrast to thermoset laminates.

• 出版日期2018-6-28