562
H. Najmi et al.
Fig. 6 Heat release rate (HRR) of three different assemblies
P.L assembly which fits quite well. In order to confirm this further, the HRR peak
duration is estimated which is about 10, 30, and 40 s for paint, laminate, and P.L
assembly, respectively. The HRR peak duration of P.L assembly is 40 s which is the
addition of HRR peak duration obtained in case of a separate test of paint (i.e., 10 s)
and laminate (i.e. 30 s). This further confirms that the primary peak corresponds to
the paint and laminate decomposition. It is also evident from the figure (Fig. 6) that
the first decomposition peak which corresponds to paint and laminate decomposition
starts and terminates at the same time in case of all the three assemblies (i.e. P.L,
P.L.H, composite). This means the addition, of honeycomb in case of P.L.H assembly
and of honeycomb and laminate in case of the composite, does not impact the primary
decomposition process. In the present multilayer composite, the peak heat release
rate is characterized by paint and laminate present at the top of the composite.
If the decomposition in all three assemblies starts with the decomposition of paint
then the time to ignition should be similar to the paint test (i.e. 36 s) which is not the
case here. It is probably due to the use of an aluminum plate in the paint test which
consumes some amount of energy when the paint is heated up and hence the ignition
time is slightly delayed.
In order to have more clarifications with the decomposition process, gaseous emissions captured during the combustion are compared (see Fig. 7). The CO emission
of a separate test of paint and laminate matches well with the CO emission of the P.L
assembly test case. This further confirms that the primary HRR peak corresponds to
paint and laminate decomposition. In the case of P.L assembly, the first peak of CO
emission is due to decomposition of both (i.e. paint and laminate) while the second
CO peak uniquely corresponds to the thermal degradation of laminate. This can also
H. Najmi et al.
Fig. 6 Heat release rate (HRR) of three different assemblies
P.L assembly which fits quite well. In order to confirm this further, the HRR peak
duration is estimated which is about 10, 30, and 40 s for paint, laminate, and P.L
assembly, respectively. The HRR peak duration of P.L assembly is 40 s which is the
addition of HRR peak duration obtained in case of a separate test of paint (i.e., 10 s)
and laminate (i.e. 30 s). This further confirms that the primary peak corresponds to
the paint and laminate decomposition. It is also evident from the figure (Fig. 6) that
the first decomposition peak which corresponds to paint and laminate decomposition
starts and terminates at the same time in case of all the three assemblies (i.e. P.L,
P.L.H, composite). This means the addition, of honeycomb in case of P.L.H assembly
and of honeycomb and laminate in case of the composite, does not impact the primary
decomposition process. In the present multilayer composite, the peak heat release
rate is characterized by paint and laminate present at the top of the composite.
If the decomposition in all three assemblies starts with the decomposition of paint
then the time to ignition should be similar to the paint test (i.e. 36 s) which is not the
case here. It is probably due to the use of an aluminum plate in the paint test which
consumes some amount of energy when the paint is heated up and hence the ignition
time is slightly delayed.
In order to have more clarifications with the decomposition process, gaseous emissions captured during the combustion are compared (see Fig. 7). The CO emission
of a separate test of paint and laminate matches well with the CO emission of the P.L
assembly test case. This further confirms that the primary HRR peak corresponds to
paint and laminate decomposition. In the case of P.L assembly, the first peak of CO
emission is due to decomposition of both (i.e. paint and laminate) while the second
CO peak uniquely corresponds to the thermal degradation of laminate. This can also