65
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_12
Chapter 12
An Innovative Experimental Approach for the Assessment
of Composite Panel Ballistic Limit
G. Portemont, R. De Coninck, and R. Ortiz
Abstract In this work, the effect of high-velocity impacts on carbon/epoxy tape quasi-isotropic laminates is studied. This
research aims at developing an experimental protocol- based Digital Images Correlation (DIC) method to determine the ballistic limit with only one test in a flat panel. Experimental tests were carried out at two different impact angles. The residual
velocity and the damaged area are used to evaluate the effect of the kinetic energy of the projectile on the laminate response.
In addition, it has been proposed as a simplified analytical approach which allows identifying the different energy absorption
mechanisms in the composite panel.
Keywords High-loading rate · Ballistic limit · Gas gun · Composite material
12.1 Introduction
High-speed impact problems have always been of interest for the commercial aviation industry. During the last decade, they
have become of greater importance due to the more significant use of composite materials, such as carbon fiber reinforced
polymers (CFRPs), in primary structural components. These components can be exposed to severe impact loads, such as
debris impact [1] and bird strike. To assert this threat the dynamic performances of the composite material are studied experimentally to estimate the limit speed that the target can withstand without perforation, e.g., the ballistic limit [2, 3]. In practice, these specific tests consist of adjusting gradually the projectile velocity until the ballistic limit is determined with a
sufficient precision. This protocol requires lots of tests; hence, a lot of composite panels. This amount is even greater since
it is necessary to perform these tests with several projectile impact angles. The work presented here aims at developing an
experimental protocol based on the Digital Image Correlation (DIC) method (with stereo-vision) to determine the ballistic
limit. For that purpose, impact experiments are performed on CFRPs stiffened panels using a gas gun and steel ball
projectiles.
12.2 Development of an Innovative Experimental Protocol
Figure 12.1 presents the gas gun and the test facility used at Onera to perform the high-velocity impacts. The structural component to be tested consists of a composite flat panel. The panel material is manufactured in triaxially braided carbon fiber
architecture (A&P Tech. QISO-L-A-52) combined with the highly toughened epoxy matrix (Hexcel HexPly M36 Resin
Film). The panels are finally supported on a rigid frame (Fig. 12.2). The shape of the steel ball projectile is spherical
(Ø = 30 mm) with an average mass of 110 g (Fig. 12.3). In the gas gun, the projectiles are supported and guided thanks to
foam sabots. The impact point is expected in the middle of the panel.
Flats panels have been used first to setup the DIC and to assess the perforation limit velocity of the composite skin. A
ballistic limit is estimated for two panel orientations (0° and 45°). The velocity of the projectile just before impact and the
G. Portemont (*) · R. De Coninck · R. Ortiz
DMAS, ONERA, Lille, France
e-mail: gerald.portemont@onera.fr; romain.de_coninck@onera.fr; roland.ortiz@onera.fr
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_12
Chapter 12
An Innovative Experimental Approach for the Assessment
of Composite Panel Ballistic Limit
G. Portemont, R. De Coninck, and R. Ortiz
Abstract In this work, the effect of high-velocity impacts on carbon/epoxy tape quasi-isotropic laminates is studied. This
research aims at developing an experimental protocol- based Digital Images Correlation (DIC) method to determine the ballistic limit with only one test in a flat panel. Experimental tests were carried out at two different impact angles. The residual
velocity and the damaged area are used to evaluate the effect of the kinetic energy of the projectile on the laminate response.
In addition, it has been proposed as a simplified analytical approach which allows identifying the different energy absorption
mechanisms in the composite panel.
Keywords High-loading rate · Ballistic limit · Gas gun · Composite material
12.1 Introduction
High-speed impact problems have always been of interest for the commercial aviation industry. During the last decade, they
have become of greater importance due to the more significant use of composite materials, such as carbon fiber reinforced
polymers (CFRPs), in primary structural components. These components can be exposed to severe impact loads, such as
debris impact [1] and bird strike. To assert this threat the dynamic performances of the composite material are studied experimentally to estimate the limit speed that the target can withstand without perforation, e.g., the ballistic limit [2, 3]. In practice, these specific tests consist of adjusting gradually the projectile velocity until the ballistic limit is determined with a
sufficient precision. This protocol requires lots of tests; hence, a lot of composite panels. This amount is even greater since
it is necessary to perform these tests with several projectile impact angles. The work presented here aims at developing an
experimental protocol based on the Digital Image Correlation (DIC) method (with stereo-vision) to determine the ballistic
limit. For that purpose, impact experiments are performed on CFRPs stiffened panels using a gas gun and steel ball
projectiles.
12.2 Development of an Innovative Experimental Protocol
Figure 12.1 presents the gas gun and the test facility used at Onera to perform the high-velocity impacts. The structural component to be tested consists of a composite flat panel. The panel material is manufactured in triaxially braided carbon fiber
architecture (A&P Tech. QISO-L-A-52) combined with the highly toughened epoxy matrix (Hexcel HexPly M36 Resin
Film). The panels are finally supported on a rigid frame (Fig. 12.2). The shape of the steel ball projectile is spherical
(Ø = 30 mm) with an average mass of 110 g (Fig. 12.3). In the gas gun, the projectiles are supported and guided thanks to
foam sabots. The impact point is expected in the middle of the panel.
Flats panels have been used first to setup the DIC and to assess the perforation limit velocity of the composite skin. A
ballistic limit is estimated for two panel orientations (0° and 45°). The velocity of the projectile just before impact and the
G. Portemont (*) · R. De Coninck · R. Ortiz
DMAS, ONERA, Lille, France
e-mail: gerald.portemont@onera.fr; romain.de_coninck@onera.fr; roland.ortiz@onera.fr