Resumo:
In recent decades, the search for high-performance materials has become increasingly
common, that is, materials that combine low weight and high mechanical strength. A
solution found was composites reinforced with fibers and polymeric matrix. However,
composite materials still have a certain deficiency of crashworthiness where a solution
to this problem lies in the use of smart materials such as shape memory alloys (NiTi)
inserted into the laminate. Therefore, this work has as main objective the development
an equation, using design of experiments, capable of predicting the energy absorption
capacity upon impact in composite materials of fiberglass and epoxy resin matrix with
inserted NiTi wires. In addition, propose a model, through numerical simulation by the
finite element method (FEM) in order to find a correlation with the experimental analysis
and consequently a reliable model for use in future work. The selection of the NiTi alloy
(Martensitic or Superelastic) to be used in the impact specimens was carried out through
the design of experiments in a complete factorial arrangement with Dynamic Mechanical
Analysis (DMA). After selecting the statistically adequate wire (Superelastic), the test
specimens were manufactured for VARTM with three design variables (Diameter, Spacing
and Position in the Laminate) following a fractional factorial arrangement and the dropweight
impact test to measure the energy absorption were conducted according to the
ASTM D7136 standard. The results obtained through the impact tests showed that there
is an increase in energy absorption when the NiTi wire is present in the composite. A
model through non-linear numerical simulation (Dynamic Analysis) was carried out and
its results were compared with those obtained experimentally, showing that there is an
excellent correlation (above 95%).
