Study of tarmac transport severity

Study of tarmac transport severity
Victor HUART a, Jean-Charles CANDORE b, Jean-Baptiste NOLOT a, Jérôme PELLOT c, Nicolas KRAJKA c ,Serge ODOF a, b and
Damien ERRE a, b
ESIReims-ESIEC : Ecole Supérieure d’Ingénieurs de Reims, Reims, France
b GRESPI / Université de Reims Champagne-Ardenne, Reims, France
Esplanade Roland Garros, BP 1029, 51686 Reims Cedex 2, France
c METROPACK
30-32, rue du Capitaine Georges Madon, ZAC Croix Blandin, 51100 Reims, France
a
Introduction
In packaging science, studying transport has a great importance to determine the viability of a couple packaging / product. During a supply chain, many failures
charges occur (handling, storage,...) but also various physical constraints (shocks, shakes, vibrations,...). All of these physical phenomena can be recorded using a
variety of customized sensors (tri-axial accelerometers, temperature sensors, pressure, ...). This work focus is done on a rarely studied transport phase. The tarmac
has many gear handling and transport characterized by typical constraints which are often more stringent than during an airlift phase. For comparison, tarmacs and
roads levels acceleration distribution will be estimated and analyzed. Based on the method proposed by S.OTARI and al. severity indicators will be calculated. The
second part will relate studies of shakes. Their distributions at 90% and 95% will be another indicator of severity and their probabilities of apparitions too. All of these
elements allow us to characterize the impact of the tarmac area during air transport.
Experimental
Comparaison of acceleration probability density
The weak acceleration area ranges is
between -0.25g and +0.25g
2.5
Probability density
2.0
1.5
1.0
With P(x), the probability density to obtain x bentween x and x+dx.
0.5
0.0
-2
-1
0
1
2
Acceleration ( G )
Tarmac repartition
Truck repatition
With Ptarm(x), the probability density to obtain x bentween x and x+dx for the tarmac.
Analysis
of
shakes
With Ptruck(x), the probability density to obtain x bentween x and x+dx for the truck.
Analysis of accelerations data
Representation of a shake
Results show that the probability of low accelerations levels is higher on
truck than tarmac.
Tarmac : 757 shakes in 2’27’’.
Truck : 419 shakes in 9’50’’
Determination of
severity
Modified gaussian
Acceleration distribution (probability density) of the system on the tarmac
Extraction of shake
acceleration
Fitting model
1.4
1.2
Probability density
1.0
Shakes repartition
Tarmac of Vatry airport (Marne, France)
Full width at half maximum
0.8
0.6
0.4
0.2
0.0
-2
-1
0
1
2
Acceleration ( G )
Gaussian repartition
Tarmac repartition
S coefficient
Acceleration distribution (probability density) of the system on the truck
2.5
Result
probability density
2.0
Truck
Truck Tarmac
1.5
1.0
FWMH modif Gauss (g)
0.896
0.949
0.5
FWMH Gauss(g)
S
0.236
0.413
1.855
0.663
0.0
-2
-1
0
1
2
Acceleration ( G )
Truck repartition
Gaussian repartition
Struck < Starmac
Tarmac is harder than truck
This indicator consist in comparaison between real FWHM and
gaussian distribution of acceleration levels of the full transport time
(S.OTARI and al).
Cumulative distribution of Vatry’s tarmac & truck at 90% and 95%.
100
Cumulative probability (%)
Conclusion
Truck
Tarmac
distribution distribution
95%
1.80 G
2.25 G
90%
1.50 G
1.85 G
Ratio 95%
1.25
Ratio 90%
1.23
80
60
40
20
0
1
2
3
Acceleration ( G )
Tarmac
Truck
95%
90%
4
5
Most of tarmac shakes are harder
than truck shakes
Conclusion
The tarmac is on average 1.6 times harder than the
truck (mean of the different parts’ ratio).