146
5
5.6 Processability of Smart and Intelligent
Composites
Emphasis is being given on the research and development of smart
and intelligent composites. It is easy to develop smart and intelligent structures in composites due to tailorability of their properties
and possibility of hybrid structures in them. The processability of
smart and intelligent composite structures involves packaging of
necessary sensors, mechanisms for obtaining desired output, and
healing response to that output [27].
5.6.1 Processability of Smart Composites
Smart composites or structures are those which can communicate
their status or condition to the observer or designer. Invariably,
these structures have mounted or embedded sensors that display
the healthy properties of the composite. For example, if a multilayer
composite is manufactured with different coloured laminas, erosion of the uppermost layer will reveal the exposed layer to be a new
colour. This new colour will indicate the number of eroded layers in
the structure because with every layer eroded, a lamina with a different colour will appear. Similarly, a strain sensor is embedded at
the location prone to failure. This sensor provides information
about the level of strains and failure due to excessive strain. The
processability of smart composites is similar to the processability of
other advanced composites; however, some other factors are outlined here.
5 The thermal stability of embedded sensors should be high
enough to sustain the curing temperature of the thermosetting
resin.
5 Sensors must be able to sustain the moulding pressure—if any.
5 The antenna or communication mechanisms must not weaken
the composite structure.
5 Arrangement for the power source of the sensor to remain
activated for the lifespan of the composite structure must be
addressed.
5.6.2 Processability of Intelligent Composites
Intelligent composites or structures are those which can identify the
defect and identify it. They have mounted or imbedded sensor(s)
along with materials and mechanisms to repair the composite at the
defect site. Therefore, intelligent composites are able to repair their
defects without external help. For example, epoxy resin-filled glass
microbeads and hardener-filled glass microbeads are placed in the
intelligent composite during its processing. Under excessive strains,
composites may experience delamination or internal cracks.
Microbeads are designed to break under excessive strain so the
resin and hardener will ooze out, filling the crack and curing at
room temperature. That’s how a crack would be repaired.
Chapter 5 · Processability of Thermosetting Composites
5
5.6 Processability of Smart and Intelligent
Composites
Emphasis is being given on the research and development of smart
and intelligent composites. It is easy to develop smart and intelligent structures in composites due to tailorability of their properties
and possibility of hybrid structures in them. The processability of
smart and intelligent composite structures involves packaging of
necessary sensors, mechanisms for obtaining desired output, and
healing response to that output [27].
5.6.1 Processability of Smart Composites
Smart composites or structures are those which can communicate
their status or condition to the observer or designer. Invariably,
these structures have mounted or embedded sensors that display
the healthy properties of the composite. For example, if a multilayer
composite is manufactured with different coloured laminas, erosion of the uppermost layer will reveal the exposed layer to be a new
colour. This new colour will indicate the number of eroded layers in
the structure because with every layer eroded, a lamina with a different colour will appear. Similarly, a strain sensor is embedded at
the location prone to failure. This sensor provides information
about the level of strains and failure due to excessive strain. The
processability of smart composites is similar to the processability of
other advanced composites; however, some other factors are outlined here.
5 The thermal stability of embedded sensors should be high
enough to sustain the curing temperature of the thermosetting
resin.
5 Sensors must be able to sustain the moulding pressure—if any.
5 The antenna or communication mechanisms must not weaken
the composite structure.
5 Arrangement for the power source of the sensor to remain
activated for the lifespan of the composite structure must be
addressed.
5.6.2 Processability of Intelligent Composites
Intelligent composites or structures are those which can identify the
defect and identify it. They have mounted or imbedded sensor(s)
along with materials and mechanisms to repair the composite at the
defect site. Therefore, intelligent composites are able to repair their
defects without external help. For example, epoxy resin-filled glass
microbeads and hardener-filled glass microbeads are placed in the
intelligent composite during its processing. Under excessive strains,
composites may experience delamination or internal cracks.
Microbeads are designed to break under excessive strain so the
resin and hardener will ooze out, filling the crack and curing at
room temperature. That’s how a crack would be repaired.
Chapter 5 · Processability of Thermosetting Composites