Abstract:
Electrically driven
continuous carbon fiber reinforced shape memory composite (CFSMPC) is a kind of
shape memory composite driven by electrical signal to realize controllable
deformation.The lightweight cellular structure of continuous carbon fiber
reinforced composites is a kind of high-performance structure with low
density.In this work, an electrically driven continuous carbon fiber reinforced
shape memory poly (lactic acid) composite hollow structure was proposed.By
controlling the temperature uniformity, the precise control of structural
deformation and the improvement of mechanical properties were realized. 3D
printing method was used to fabricate hollow composite structures. The effects
of geometric parameters on mechanical properties and shape recovery performance
of hollow composite structures were investigated by experiments.The results show
that the tensile strength of hollow structure is improved compared with that of
non-hollow structure, and the smaller the cell width, the more obvious the
tensile strength increases.With the carbon fiber reinforced, the strength of
hollow structure is significantly improved, and the strength of CP-3 sample is
66% higher than that of non-hollow PLA.Hollow cell width determines the carbon
fiber volume fraction of hollow structure, which affects the mechanical
properties of CFSMPC.Moreover, the interfacial properties between printing
layers of composite materials are higher.The results show that the volume
content of single cell fiber is closely related to tensile strength.In addition,
the shape memory recovery speed and the maximum recovery force of CFSMPC hollow
structure are obviously increased, and the fastest recovery is completed in
11s.The recovery force of samples is significantly improved.The results show
that hollow structure can further release the shape memory performance of
structure and obtain higher quality structure-function integrated intelligent
material.This is because the hollow structure can effectively avoid the low
temperature zone caused by the thermal diffusion of carbon fiber, which can
ensure the temperature uniformity of the whole structure.Finally, a coupled
electro-thermal-mechanical finite element model of CFSMPC hollow structure is
proposed based on viscoelastic constitutive model. The predicted temperature
distribution and recovery time are in good agreement with the experimental
results, and the error is within 15%.The distribution of internal stress during
the recovery process of hollow structure deformation can be obtained by
simulation analysis, and it proves that cell width affects the stress release of
single cell, which is the difference of shape recovery performance at macro
level.Therefore, the model can guide the optimization of CFSMPC structure
design.