9 research outputs found
Experimental Analysis of the Influence of Structural Parameters on the Behavior of Glass-Fiber Reinforced Polypropylene Composites
In a composite material reinforced by short
random fibers, damage results from different
elementary failure mechanisms such as matrix
micro-cracking, fiber pull out, failure of
fiber/matrix interface, failure of fibers, etc.
These damages have a large influence on the
macroscopic behavior of composite materials.
To obtain a good mechanical performance of a
composite material, it is important to optimize
the fiber ratio and the quality of the
fiber/matrix interface, which have a direct
influence on the damage mentioned above. The
main objective of this study is to determine the
influence of structural parameters on the
evolution of damage for two types of polypropylene
glass-fiber reinforced composites. In
parallel with a classical approach of the
mechanical theory of damage, which consists in
load-unload tensile tests, the use of acoustic
emission allows one to follow in real time the
character and the importance of damage
mechanisms in the course of loading. In
addition, fractographic analysis makes it
possible to confirm different assumptions and
conclusions from this study.Π ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠΌ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π΅, Π°ΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΌ ΡΠ»ΡΡΠ°ΠΉΠ½ΠΎ ΡΠ°ΡΠΏΠΎΠ»ΠΎΠΆΠ΅Π½Π½ΡΠΌΠΈ ΠΊΠΎΡΠΎΡΠΊΠΈΠΌΠΈ Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ,
ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΡ ΠΏΡΠΈ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΌ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΠΈ Π²ΠΎΠ·Π½ΠΈΠΊΠ°ΡΡ Π² ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΡΠ°Π·Π½ΡΡ
ΡΠ»Π΅ΠΌΠ΅Π½ΡΠ°ΡΠ½ΡΡ
ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠ², ΡΠ°ΠΊΠΈΡ
ΠΊΠ°ΠΊ ΠΌΠΈΠΊΡΠΎΡΠ°ΡΡΡΠ΅ΡΠΊΠΈΠ²Π°Π½ΠΈΠ΅ ΠΌΠ°ΡΡΠΈΡΡ, Π²ΡΠ΄Π΅ΡΠ³ΠΈΠ²Π°Π½ΠΈΠ΅ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½,
ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΠ΅ ΠΌΠ΅ΠΆΡΠ°Π·Π½ΠΎΠΉ Π³ΡΠ°Π½ΠΈΡΡ Π²ΠΎΠ»ΠΎΠΊΠ½ΠΎ-ΠΌΠ°ΡΡΠΈΡΠ°, ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΠ΅ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½. ΠΡΠΈ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΡ
ΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ Π±ΠΎΠ»ΡΡΠΎΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΠΌΠ°ΠΊΡΠΎΡΠΊΠΎΠΏΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π°.
ΠΠ»Ρ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΡ ΠΏΡΠΈΠ΅ΠΌΠ»Π΅ΠΌΡΡ
ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Π²Π°ΠΆΠ½ΠΎ
ΠΎΠΏΡΠΈΠΌΠΈΠ·ΠΈΡΠΎΠ²Π°ΡΡ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΠΌΠ΅ΠΆΡΠ°Π·Π½ΠΎΠΉ Π³ΡΠ°Π½ΠΈΡΡ Π²ΠΎΠ»ΠΎΠΊΠ½ΠΎ-
ΠΌΠ°ΡΡΠΈΡΠ°, ΠΊΠΎΡΠΎΡΡΠ΅ ΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ Π½Π΅ΠΏΠΎΡΡΠ΅Π΄ΡΡΠ²Π΅Π½Π½ΠΎΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΠΏΠ΅ΡΠ΅ΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ Π²ΡΡΠ΅ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΡ.
ΠΠ»Π°Π²Π½ΠΎΠΉ ΡΠ΅Π»ΡΡ ΡΡΠ°ΡΡΠΈ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ Π²Π»ΠΈΡΠ½ΠΈΡ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² Π½Π°
ΡΠ²ΠΎΠ»ΡΡΠΈΡ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π°Π΅ΠΌΠΎΡΡΠΈ Π΄Π²ΡΡ
ΡΠΈΠΏΠΎΠ² ΡΡΠ΅ΠΊΠ»ΠΎΠΏΠ»Π°ΡΡΠΈΠΊΠΎΠ² Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΠΎΠ»ΠΈΠΏΡΠΎΠΏΠΈΠ»Π΅Π½Π°. ΠΠ΄Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎ
Ρ ΠΊΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΈΠΌ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄ΠΎΠΌ ΠΊ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅ΠΎΡΠΈΠΈ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π°Π΅ΠΌΠΎΡΡΠΈ, ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΠΎΠΉ Π½Π°
ΠΈΡΠΏΡΡΠ°Π½ΠΈΡΡ
Π½Π° ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΠ΅ Ρ ΠΏΠ΅ΡΠΈΠΎΠ΄ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ°Π·Π³ΡΡΠ·ΠΊΠΎΠΉ, ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄Π° Π°ΠΊΡΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ
ΡΠΌΠΈΡΡΠΈΠΈ Π΄Π°Π΅Ρ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΠΈΠ·ΡΡΠ°ΡΡ Π² ΡΠ΅Π°Π»ΡΠ½ΠΎΠΌ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΏΡΠΈΡΠΎΠ΄Ρ ΠΈ Π²Π°ΠΆΠ½ΠΎΡΡΡ
ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠ² ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΠΉ Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ. Π Π΄ΠΎΠΏΠΎΠ»Π½Π΅Π½ΠΈΠ΅ ΠΊ ΡΡΠΎΠΌΡ ΡΡΠ°ΠΊΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΉ
Π°Π½Π°Π»ΠΈΠ· ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠ΄ΠΈΡΡ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠ΅ ΠΏΡΠ΅Π΄ΠΏΠΎΡΡΠ»ΠΊΠΈ ΠΈ Π·Π°ΠΊΠ»ΡΡΠ΅Π½ΠΈΡ Π½Π°ΡΡΠΎΡΡΠ΅Π³ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ.Π£ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠΌΡ ΠΌΠ°ΡΠ΅ΡΡΠ°Π»Ρ, ΡΠΎ Π°ΡΠΌΠΎΠ²Π°Π½ΠΈΠΉ Π²ΠΈΠΏΠ°Π΄ΠΊΠΎΠ²ΠΎ ΡΠΎΠ·ΡΠ°ΡΠΎΠ²Π°Π½ΠΈΠΌΠΈ ΠΊΠΎΡΠΎΡΠΊΠΈΠΌΠΈ
Π²ΠΎΠ»ΠΎΠΊΠ½Π°ΠΌΠΈ, ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Π½Ρ ΠΏΡΠΈ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½ΠΎΠΌΡ Π½Π°Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½Ρ Π²ΠΈΠ½ΠΈΠΊΠ°ΡΡΡ
Π²Π½Π°ΡΠ»ΡΠ΄ΠΎΠΊ Π΄ΡΡ ΡΡΠ·Π½ΠΈΡ
Π΅Π»Π΅ΠΌΠ΅Π½ΡΠ°ΡΠ½ΠΈΡ
ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΡΠ², ΡΠ°ΠΊΠΈΡ
ΡΠΊ ΠΌΡΠΊΡΠΎΡΠΎΠ·ΡΡΡΡΠΊΡΠ²Π°Π½Π½Ρ
ΠΌΠ°ΡΡΠΈΡΡ, Π²ΠΈΡΠΌΠΈΠΊΡΠ²Π°Π½Π½Ρ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½, ΡΡΠΉΠ½ΡΠ²Π°Π½Π½Ρ ΠΌΡΠΆΡΠ°Π·ΠΎΠ²ΠΎΡ Π³ΡΠ°Π½ΠΈΡΡ Π²ΠΎΠ»ΠΎΠΊΠ½ΠΎ-
ΠΌΠ°ΡΡΠΈΡΡ, ΡΡΠΉΠ½ΡΠ²Π°Π½Π½Ρ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½. Π¦Ρ ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Π½Ρ Π·ΡΠΌΠΎΠ²Π»ΡΡΡΡ Π·Π½Π°ΡΠ½ΠΈΠΉ Π²ΠΏΠ»ΠΈΠ²
Π½Π° ΠΌΠ°ΠΊΡΠΎΡΠΊΠΎΠΏΡΡΠ½Ρ Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΡΠ°Π»Ρ. Π©ΠΎΠ± ΠΎΡΡΠΈΠΌΠ°ΡΠΈ ΠΏΡΠΈΠΉΠ½ΡΡΠ½Ρ
ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½Ρ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΡΠ°Π»Ρ, Π²Π°ΠΆΠ»ΠΈΠ²ΠΎ ΠΎΠΏΡΠΈΠΌΡ-
Π·ΡΠ²Π°ΡΠΈ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΡΡ Π²ΠΎΠ»ΠΎΠΊΠΎΠ½, Π° ΡΠ°ΠΊΠΎΠΆ ΡΠΊΡΡΡΡ ΠΌΡΠΆΡΠ°Π·ΠΎΠ²ΠΎΡ Π³ΡΠ°Π½ΠΈΡΡ Π²ΠΎΠ»ΠΎΠΊΠ½ΠΎ-
ΠΌΠ°ΡΡΠΈΡΡ, ΡΠΊΡ Π±Π΅Π·ΠΏΠΎΡΠ΅ΡΠ΅Π΄Π½ΡΠΎ Π²ΠΏΠ»ΠΈΠ²Π°ΡΡΡ Π½Π° ΡΡ ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Π½Ρ. ΠΠΎΠ»ΠΎΠ²Π½Π° ΠΌΠ΅ΡΠ°
ΡΠΎΠ±ΠΎΡΠΈ - Π²ΠΈΠ·Π½Π°ΡΠ΅Π½Π½Ρ Π²ΠΏΠ»ΠΈΠ²Ρ ΡΡΡΡΠΊΡΡΡΠ½ΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡΠ² Π½Π° Π΅Π²ΠΎΠ»ΡΡΡΡ ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Π½Ρ
Π΄Π²ΠΎΡ
ΡΠΈΠΏΡΠ² ΡΠΊΠ»ΠΎΠΏΠ»Π°ΡΡΠΈΠΊΡΠ² Π½Π° ΠΎΡΠ½ΠΎΠ²Ρ ΠΏΠΎΠ»ΡΠΏΡΠΎΠΏΡΠ»Π΅Π½Ρ. ΠΠ΄Π½ΠΎΡΠ°ΡΠ½ΠΎ Π·
ΠΊΠ»Π°ΡΠΈΡΠ½ΠΈΠΌ ΠΏΡΠ΄Ρ
ΠΎΠ΄ΠΎΠΌ Π΄ΠΎ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½ΠΎΡ ΡΠ΅ΠΎΡΡΡ ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Π½Ρ, ΡΠΎ Π·Π°ΡΠ½ΠΎΠ²Π°Π½Π° Π½Π°
Π²ΠΈΠΏΡΠΎΠ±ΡΠ²Π°Π½Π½ΡΡ
Π½Π° ΡΠΎΠ·ΡΡΠ³ ΡΠ· ΠΏΠ΅ΡΡΠΎΠ΄ΠΈΡΠ½ΠΈΠΌ ΡΠΎΠ·Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½ΡΠΌ, Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ
ΠΌΠ΅ΡΠΎΠ΄Ρ Π°ΠΊΡΡΡΠΈΡΠ½ΠΎΡ Π΅ΠΌΡΡΡΡ Π΄Π°Ρ Π·ΠΌΠΎΠ³Ρ Π²ΠΈΠ²ΡΠ°ΡΠΈ Π² ΡΠ΅Π°Π»ΡΠ½ΠΎΠΌΡ ΡΠ°ΡΡ ΠΏΡΠΈΡΠΎΠ΄Ρ Ρ
Π²Π°ΠΆΠ»ΠΈΠ²ΡΡΡΡ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌΡΠ² ΠΏΠΎΡΠΊΠΎΠ΄ΠΆΠ΅Π½Ρ Ρ ΠΏΡΠΎΡΠ΅ΡΡ Π½Π°Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½Ρ. ΠΠΎΠ΄Π°ΡΠΊΠΎΠ²ΠΎ Π΄ΠΎ
ΡΡΠΎΠ³ΠΎ ΡΡΠ°ΠΊΡΠΎΠ³ΡΠ°ΡΡΡΠ½ΠΈΠΉ Π°Π½Π°Π»ΡΠ· Π΄ΠΎΠ·Π²ΠΎΠ»ΡΡ ΠΏΡΠ΄ΡΠ²Π΅ΡΠ΄ΠΈΡΠΈ ΡΡΠ·Π½Ρ ΠΏΠ΅ΡΠ΅Π΄ΡΠΌΠΎΠ²ΠΈ Ρ
Π²ΠΈΡΠ½ΠΎΠ²ΠΊΠΈ Π΄Π°Π½ΠΎΠ³ΠΎ Π΄ΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½Π½Ρ
Fracture Process in Β± ΞΈ Laminates Subjected to Mode II Loading
This work studies the behavior of a multidirectional laminate under Mode II loading. We describe the process of delamination in a reinforced composite of glass/epoxy. The stacking sequence (plies orientation [Β±ΞΈ]) was selected to minimize the coupling effects. The Mode II interlaminar test under three-point bending and cantilever flexure using ENF (End Notch Flexure) and ELS (End Load Split) specimens, respectively, was performed and analyzed. The test procedures and the results of strain-energy-release rate study for crack initiation are presented. The fracture process and the mechanical behavior of the two types of specimens are analyzed. The analysis clearly shows a close link between the angle ΞΈ, the ratio a/L, and the thickness h of the specimen. Fracture by delamination can be obtained only with an optimal choice of these parameters. The analysis of the states of stresses at the tip of crack allows us to explain the phenomenon of bifurcation between plies and is confirmed by the experimental results.ΠΡΡΠ»Π΅Π΄ΡΠ΅ΡΡΡ ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΠΌΠ½ΠΎΠ³ΠΎΠΌΠ΅ΡΠ½ΠΎΠ³ΠΎ Π»Π°ΠΌΠΈΠ½Π°ΡΠ° ΠΏΡΠΈ Π΅Π³ΠΎ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΠΈ ΠΏΠΎ ΡΠΈΠΏΡ KII . ΠΠΏΠΈΡΠ°Π½ ΠΏΡΠΎΡΠ΅ΡΡ Π΄Π΅Π»Π°ΠΌΠΈΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠΏΡΠΎΡΠ½Π΅Π½Π½ΠΎΠ³ΠΎ ΡΡΠ΅ΠΊΠ»ΠΎΡΠΏΠΎΠΊΡΠΈΠ΄Π½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ°. ΠΠ»Ρ ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΡΡΡΠ΅ΠΊΡΠΎΠ² ΡΡΠ΅Π½ΠΈΡ Π²ΡΠ±ΡΠ°Π½Π° ΠΎΡΠΈΠ΅Π½ΡΠ°ΡΠΈΡ Β± ΞΈ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Π° ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° ΠΌΠ΅ΠΆΠ»Π°ΠΌΠΈΠ½Π°ΡΠ½ΡΡ
ΠΈΡΠΏΡΡΠ°Π½ΠΈΠΉ ΠΏΠΎ ΡΠΈΠΏΡ KII Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΡ
Π΅ΠΌ ΡΡΠ΅Ρ
ΡΠΎΡΠ΅ΡΠ½ΠΎΠ³ΠΎ ΠΈ ΠΊΠΎΠ½ΡΠΎΠ»ΡΠ½ΠΎΠ³ΠΎ ΠΈΠ·Π³ΠΈΠ±Π° ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΡΠΈΠΏΠ° ENF (ΡΠΎΡΡΠ΅Π²ΠΎΠ΅ Π·Π°ΡΠ΅ΠΌΠ»Π΅Π½ΠΈΠ΅ Ρ ΠΊΠΎΠ½ΡΠΎΠ»ΡΠ½ΡΠΌ ΠΈΠ·Π³ΠΈΠ±ΠΎΠΌ Π½Π°Π³ΡΡΠ·ΠΊΠΎΠΉ, ΡΠ°Π²Π½ΠΎΠΌΠ΅ΡΠ½ΠΎ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΠΎΠΉ ΠΏΠΎ ΡΠΈΡΠΈΠ½Π΅ ΡΠ²ΠΎΠ±ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΡΠΎΡΡΠ°) ΠΈ ELS (ΡΠ°ΡΠ½ΠΈΡΠ½ΠΎ Π·Π°ΠΊΡΠ΅ΠΏΠ»Π΅Π½Π½Π°Ρ Π±Π°Π»ΠΊΠ° Ρ ΡΠ΅Π½ΡΡΠ°Π»ΡΠ½ΠΎΠΉ Π½Π°Π³ΡΡΠ·ΠΊΠΎΠΉ, ΡΠ°Π²Π½ΠΎΠΌΠ΅ΡΠ½ΠΎ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΠΎΠΉ ΠΏΠΎ ΡΠΈΡΠΈΠ½Π΅ Π±Π°Π»ΠΊΠΈ). ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠ΅ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ ΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠΊΠΎΡΠΎΡΡΠ΅ΠΉ Π²ΡΡΠ²ΠΎΠ±ΠΎΠΆΠ΄Π΅Π½ΠΈΡ ΡΠ½Π΅ΡΠ³ΠΈΠΈ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΏΡΠΈ ΠΈΠ½ΠΈΡΠΈΠΈΡΠΎΠ²Π°Π½ΠΈΠΈ ΡΡΠ΅ΡΠΈΠ½. ΠΠ»Ρ Π΄Π²ΡΡ
Π²ΡΡΠ΅ΡΠΊΠ°Π·Π°Π½Π½ΡΡ
ΡΠΈΠΏΠΎΠ² ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½ ΠΏΡΠΎΡΠ΅ΡΡ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΡ ΠΈ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π°. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½Π° ΡΠ΅ΡΠ½Π°Ρ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ²ΡΠ·Ρ ΠΌΠ΅ΠΆΠ΄Ρ Π²Π΅Π»ΠΈΡΠΈΠ½Π°ΠΌΠΈ ΡΠ³Π»Π° ΞΈ, ΡΠΎΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠ΅ΠΌ a/L ΠΈ ΡΠΎΠ»ΡΠΈΠ½ΠΎΠΉ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² h. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΠ΅ Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ Π΄Π΅Π»Π°ΠΌΠΈΠ½Π°ΡΠΈΠΈ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎ ΡΠΎΠ»ΡΠΊΠΎ ΠΏΡΠΈ ΡΡΠ»ΠΎΠ²ΠΈΠΈ ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΠ±ΠΎΡΠ° ΡΡΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ². ΠΠ½Π°Π»ΠΈΠ· Π½Π°ΠΏΡΡΠΆΠ΅Π½Π½ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ Π² Π²Π΅ΡΡΠΈΠ½Π΅ ΡΡΠ΅ΡΠΈΠ½Ρ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΠΎΠ±ΡΡΡΠ½ΠΈΡΡ ΡΠ²Π»Π΅Π½ΠΈΠ΅ ΠΌΠ΅ΠΆΡΠ»ΠΎΠΉΠ½ΠΎΠΉ Π±ΠΈΡΡΡΠΊΠ°ΡΠΈΠΈ, Π΅Π³ΠΎ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ Ρ
ΠΎΡΠΎΡΠΎ ΡΠΎΠ³Π»Π°ΡΡΡΡΡΡ Ρ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠΌΠΈ Π΄Π°Π½Π½ΡΠΌΠΈ.ΠΠΎΡΠ»ΡΠ΄ΠΆΡΡΡΡΡΡ ΠΏΠΎΠ²Π΅Π΄ΡΠ½ΠΊΠ° Π±Π°Π³Π°ΡΠΎΠ²ΠΈΠΌΡΡΠ½ΠΎΠ³ΠΎ Π»Π°ΠΌΡΠ½Π°ΡΠ° ΠΏΡΠΈ ΠΉΠΎΠ³ΠΎ Π½Π°Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½Ρ Π·Π° ΡΠΈΠΏΠΎΠΌ KII . ΠΠΏΠΈΡΠ°Π½ΠΎ ΠΏΡΠΎΡΠ΅Ρ Π΄Π΅Π»Π°ΠΌΡΠ½ΡΠ²Π°Π½Π½Ρ Π·ΠΌΡΡΠ½Π΅Π½ΠΎΠ³ΠΎ ΡΠΊΠ»ΠΎΠ΅ΠΏΠΎΠΊΡΠΈΠ΄Π½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠ°. ΠΠ»Ρ ΠΌΡΠ½ΡΠΌΡΠ·Π°ΡΡΡ Π΅ΡΠ΅ΠΊΡΡΠ² ΡΠ΅ΡΡΡ Π²ΠΈΠ±ΡΠ°Π½ΠΎ ΠΎΡΡΡΠ½ΡΠ°ΡΡΡ Β± ΞΈ. Π ΠΎΠ·Π³Π»ΡΠ½ΡΡΠΎ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΡ ΠΌΡΠΆΠ»Π°ΠΌΡΠ½Π°ΡΠ½ΠΈΡ
Π²ΠΈΠΏΡΠΎΠ±ΡΠ²Π°Π½Ρ Π·Π° ΡΠΈΠΏΠΎΠΌ KII ΡΠ· Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½ΡΠΌ ΡΡ
Π΅ΠΌ ΡΡΠΈΡΠΎΡΠΊΠΎΠ²ΠΎΠ³ΠΎ Ρ ΠΊΠΎΠ½ΡΠΎΠ»ΡΠ½ΠΎΠ³ΠΎ Π·Π³ΠΈΠ½Ρ Π²ΡΠ΄ΠΏΠΎΠ²ΡΠ΄Π½ΠΎ Π·ΡΠ°Π·ΠΊΡΠ² ΡΠΈΠΏΡ ENF (ΡΠΎΡΡΠ΅Π²Π΅ Π·Π°ΡΠΈΡΠ½Π΅Π½Π½Ρ Π· ΠΊΠΎΠ½ΡΠΎΠ»ΡΠ½ΠΈΠΌ Π·Π³ΠΈΠ½ΠΎΠΌ Π½Π°Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½ΡΠΌ, ΡΠΎ ΡΡΠ²Π½ΠΎΠΌΡΡΠ½ΠΎ ΡΠΎΠ·ΠΏΠΎΠ΄ΡΠ»Π΅Π½Π΅ ΠΏΠΎ ΡΠΈΡΠΈΠ½Ρ Π²ΡΠ»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΡΡΡ) Ρ ELS (ΡΠ°ΡΠ½ΡΡΠ½ΠΎ Π·Π°ΠΊΡΡΠΏΠ»Π΅Π½Π° Π±Π°Π»ΠΊΠ° Π· ΡΠ΅Π½ΡΡΠ°Π»ΡΠ½ΠΈΠΌ Π½Π°Π²Π°Π½ΡΠ°ΠΆΠ΅Π½Π½ΡΠΌ, ΡΠΎ ΡΡΠ²Π½ΠΎΠΌΡΡΠ½ΠΎ ΡΠΎΠ·ΠΏΠΎΠ΄ΡΠ»Π΅Π½Π΅ ΠΏΠΎ ΡΠΈΡΠΈΠ½Ρ Π±Π°Π»ΠΊΡ). ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ΠΎ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΈ ΡΠΎΠ΄ΠΎ ΡΠ²ΠΈΠ΄ΠΊΠΎΡΡΠ΅ΠΉ Π·Π²ΡΠ»ΡΠ½Π΅Π½Π½Ρ Π΅Π½Π΅ΡΠ³ΡΡ Π΄Π΅ΡΠΎΡΠΌΠ°ΡΡΡ ΠΏΡΠΈ ΡΠ½ΡΡΡΡΠ²Π°Π½Π½Ρ ΡΡΡΡΠΈΠ½. ΠΠ»Ρ Π΄Π²ΠΎΡ
Π²ΠΈΡΠ΅Π²ΠΊΠ°Π·Π°Π½ΠΈΡ
ΡΠΈΠΏΡΠ² Π·ΡΠ°Π·ΠΊΡΠ² ΠΏΡΠΎΠ°Π½Π°Π»ΡΠ·ΠΎΠ²Π°Π½ΠΎ ΠΏΡΠΎΡΠ΅Ρ ΡΡΠΉΠ½ΡΠ²Π°Π½Π½Ρ Ρ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½ΠΎΡ ΠΏΡΠΎΠ²Π΅Π΄ΡΠ½ΠΊΠΈ ΠΌΠ°ΡΠ΅ΡΡΠ°Π»Ρ. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ ΠΊΠΎΡΠ΅Π»ΡΡΡΠΉΠ½ΠΈΠΉ Π·Π²βΡΠ·ΠΎΠΊ ΠΌΡΠΆ Π²Π΅Π»ΠΈΡΠΈΠ½Π°ΠΌΠΈ ΠΊΡΡΠ° ΞΈ, Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Π½ΡΠΌ a /L Ρ ΡΠΎΠ²ΡΠΈΠ½ΠΎΡ Π·ΡΠ°Π·ΠΊΡΠ² h. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΠΎ ΡΡΠΉΠ½ΡΠ²Π°Π½Π½Ρ Π²Π½Π°ΡΠ»ΡΠ΄ΠΎΠΊ Π΄Π΅Π»Π°ΠΌΡΠ½Π°ΡΡΡ ΠΌΠΎΠΆΠ»ΠΈΠ²Π΅ Π»ΠΈΡΠ΅ Π·Π° ΡΠΌΠΎΠ²ΠΈ ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΠΈΠ±ΠΎΡΡ ΡΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡΠ². ΠΠ½Π°Π»ΡΠ· Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΎΠ³ΠΎ ΡΡΠ°Π½Ρ Ρ Π²ΡΡΡΡΡ ΡΡΡΡΠΈΠ½ΠΈ Π΄ΠΎΠ·Π²ΠΎΠ»ΡΡ ΠΏΠΎΡΡΠ½ΠΈΡΠΈ ΡΠ²ΠΈΡΠ΅ ΠΌΡΠΆΡΠ°ΡΠΎΠ²ΠΎΡ Π±ΡΡΡΡΠΊΠ°ΡΡΡ Ρ Π΄ΠΎΠ±ΡΠ΅ ΡΠ·Π³ΠΎΠ΄ΠΆΡΡΡΡΡΡ ΡΠ· Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΈΠΌΠΈ Π΄Π°Π½ΠΈΠΌΠΈ
Ewingβs sarcoma of the mobile spine: Three unusual observations
Background. Ewingβs sarcoma is a bony highly malignant tumour, it occurs most frequently in the second decade of life. Ewingβs sarcoma is a rare affection, located usually in the pelvis, the femur, the humerus, the ribs, the mandible and clavicle, other location are rare especially in the spine. We report three cases of spinal Ewingβs sarcoma, two primary spine locations and one on young adult with unusual clinical presentation.
Cases presentation
Case 1. The first patient is a girl of 14 years old without past medical history. She presented initially two months before consultation a neck pain followed days after by a weakness of the left upper limb; the spine imaging performed objectified a destructive process of C2 with a spinal cord compression. The patient was operated beneficiating of a spinal cord decompression and a subtotal removal of the tumour. The pathologistβs results were in favour of Ewingβs sarcoma and the patient was oriented to oncology.
Case 2. The second patient is a man of 31 years old operated five years before he consulted for shoulder Ewingβs sarcoma followed by chemotherapy and radiotherapy, he presented two months before consultation a cauda equina syndrome. Spine MRI objectified a double location of an epidural tumour at T3-T4 and S1-S2 levels. The patient was operated beneficiating of subtotal removal of the tumour. The laboratory exam results were in favour of Ewingβs sarcoma and the patient was oriented to oncology.
Case 3. The third patient is a 6 years old boy who presented a 1 month history of low back pain followed by a rapidly deteriorating weakness of both lower limbs over a weak. On examination there was bilateral spastic paraplegia, hypoesthesia below the level of Th10 and a urinary retention. The MRI imaging revealed a lesion on the levels Th8, Th9 and Th10 vertebras involving the body, pedicle, lamina, and the transverse process on the left side with an epidural invasion compressing the spinal cord. The tumour was radically removed. Pathology report was in favour of Ewingβs sarcoma. Two weeks after surgery the patient was able to walk. He was referred for adjuvant systemic chemotherapy.
Conclusion. Ewingβs sarcoma is rare malignant tumour. The location in the spine exposes the patient to more complications because of the neurostructures compression. The surgical total removal followed by radio and chemotherapy is the only option with the best prognostic and guaranties an acceptable life quality
Interlaminar Fracture Toughness Evaluation in Glass/Epoxy Composites Using Acoustic Emission and Finite Element Methods
Β© 2014, ASM International. Delamination is one of the most common modes of failure in laminated composites and it leads to the loss of structural strength and stiffness. In this paper, mode I, mode II, and mixed of these pure modes were investigated using mechanical data, Finite Element Method (FEM) and Acoustic Emission (AE) signals. Experimental data were obtained from insitu monitoring of glass/epoxy laminated composites with different lay-ups when subjected to different modes of failure. The main objective was to investigate the behavior of delamination propagation and to evaluate the critical value of the strain energy which is required for onset of the delamination (GC). For the identification of interlaminar fracture toughness of the specimens, four methods were used: (a) ASTM standard methods, (b) FEM analysis, (c) AE method, and (d) sentry function method which is a function of mechanical and AE behaviors of the specimens. The results showed that the GC values obtained by the sentry function method and FEM analysis were in a close agreement with the results of nonlinearity methods which is recommended in the ASTM standards. It was also found that the specimens under different loading conditions and various lay-up have different GC values. These differences are related to different stress components distribution in the specimens which induce various damage mechanisms. Accordingly, stress components distribution obtained from FEM analyses were in agreement with SEM observations of the damaged surfaces of the specimens
Mode II delamination in Β± laminates: Analysis and optimisation
International audienceThe literature concerning Β± laminates under mode II (propagation mode) loading encounters a difficulty in calculation of the structural dimensions. Indeed, it is rare to have a specimen geometry which fully satisfies the conditions for application of the Linear Elastic Fracture Mechanics (LEFM). Thus, the aim of this work is the optimisation of the specimen geometry which allows the characterisation of mode II by the approach of the LEFM concept. The results obtained show an interaction between the geometrical characteristics of the specimen (thickness h), the angle of orientation of the plies () and the characterisation of delamination. The experimental results are in good agreement with the analytical predictions. The use of the acoustic emission allows us to observe that delamination is only one final stage in a process of damage which starts well before