147
5
Sensor-based intelligent composites have sensor(s) mounted or
embedded in the composite along with the repair material and
actuator. For example, intelligent composite bridges have embedded and/or mounted sensors to sense the development of a crack. A
signal is received by the actuator, and it releases the requisite
amount of repair material at the crack site automatically. As a result,
the crack is filled and is cured at room temperature. The only
requirement in such cases is to check the quantity of the repair
material in the reservoir so that enough repair material is available.
The processability of intelligent composites is similar to that of
other advanced composites; however, some other factors are outlined here.
5 Thermal stability of the embedded sensor and repair mechanism should be high enough to sustain the curing temperature
of the thermosetting resin.
5 Sensor and repair mechanisms must be able to sustain the
moulding pressure—if any.
5 The sensor and repair mechanism must not weaken the
composite structure.
5 The shelf life of the embedded repair material must be long
enough to sustain the serviceability and repair of the composite structure.
5 Mechanisms used to replenish external repair material must be
available.
5 Arrangement for the power source of the sensor to remain
activated for the lifespan of the composite structure must be
addressed.
To Be Remembered
1. Interface is the bonding surface between the reinforcement
and the matrix across which a discontinuity in some
parameter occurs.
2. Interphase is the continuous region of dissimilar composition between the reinforcement and the matrix.
3. There is a labile link between the reinforcement and the
matrix through interphase. This labile link causes the
shifting of the interphase bond position.
4. Particles are regular-shaped, small-sized entities.
5. Whiskers are irregular-shaped, small-sized entities.
6. Cure cycle is a time and temperature combination used to
cross-link the thermosetting resin, providing optimum
properties.
7. Cross-link density is the direct measure of the extent of
curing for thermosetting resins.
8. Wetting the fibres of the matrix is essential to form a
continuous interphase region.
9. Chemical bonding between the matrix and the reinforcement is the most effective method of increasing the
interfacial bond strength.
10. The mutual solubility of two materials is interdiffusion.
5.6 · Processability of Smart and Intelligent Composites
5
Sensor-based intelligent composites have sensor(s) mounted or
embedded in the composite along with the repair material and
actuator. For example, intelligent composite bridges have embedded and/or mounted sensors to sense the development of a crack. A
signal is received by the actuator, and it releases the requisite
amount of repair material at the crack site automatically. As a result,
the crack is filled and is cured at room temperature. The only
requirement in such cases is to check the quantity of the repair
material in the reservoir so that enough repair material is available.
The processability of intelligent composites is similar to that of
other advanced composites; however, some other factors are outlined here.
5 Thermal stability of the embedded sensor and repair mechanism should be high enough to sustain the curing temperature
of the thermosetting resin.
5 Sensor and repair mechanisms must be able to sustain the
moulding pressure—if any.
5 The sensor and repair mechanism must not weaken the
composite structure.
5 The shelf life of the embedded repair material must be long
enough to sustain the serviceability and repair of the composite structure.
5 Mechanisms used to replenish external repair material must be
available.
5 Arrangement for the power source of the sensor to remain
activated for the lifespan of the composite structure must be
addressed.
To Be Remembered
1. Interface is the bonding surface between the reinforcement
and the matrix across which a discontinuity in some
parameter occurs.
2. Interphase is the continuous region of dissimilar composition between the reinforcement and the matrix.
3. There is a labile link between the reinforcement and the
matrix through interphase. This labile link causes the
shifting of the interphase bond position.
4. Particles are regular-shaped, small-sized entities.
5. Whiskers are irregular-shaped, small-sized entities.
6. Cure cycle is a time and temperature combination used to
cross-link the thermosetting resin, providing optimum
properties.
7. Cross-link density is the direct measure of the extent of
curing for thermosetting resins.
8. Wetting the fibres of the matrix is essential to form a
continuous interphase region.
9. Chemical bonding between the matrix and the reinforcement is the most effective method of increasing the
interfacial bond strength.
10. The mutual solubility of two materials is interdiffusion.
5.6 · Processability of Smart and Intelligent Composites