|
CSME 2023/06
Volume 44 No.3
:
273-285
|
|
Perforation and Failure-Tolerant Mechanism of AA/CFRP Stack Sheets Under Quasi-Static Loading Conditions
Zhaobing Liua, Yaoyao Yua and Kerui Penga
aSchool of Mechanical and Electrical Engineering, Wuhan University of Technology，Wuhan 430070, China.
|
Abstract:
Loading conditions have a strong influence on the mechanical performance of Aluminum Alloy(AA)/Carbon Fiber Reinforced Plastic (CFRP) stack sheets. However, the understanding of its deformation behavior under perforation loading is still limited. The aim of this study is to investigate the perforation and failure tolerance mechanism of AA/CFRP stack sheets when subjected to quasi-static perforation loads. The effects of factors such as layer arrangement, tool indenter size, and mechanical properties of each layer on the mechanical performance of AA/CFRP stack sheets were analyzed by analytical and/or experimental methods under quasi-static penetration loading conditions. During the quasi-static penetration loading, layer arrangement is the most dominating factor affecting the penetration deformation behaviors. If the CFRP layer faces the tool indenter, failure in the AA metal layer could be advanced to some extent. A dishing deformation is observed first. Then, tensile tearing at the center of the sheet dominates the failure mode. When the AA layer faces the tool indenter, the mechanical behavior of the stack sheet strongly depends on the failure mode of the metal plate. It is noting that the metal layer fails in a very similar way to the monolithic metal sheet.Nevertheless, the CFRP sheet was able to resist more bending deformation of the metal layer, thereby increasing energy dissipation. Furthermore, increasing the thickness of the CFRP sheet could postpone the fracture of the metal layer. In addition, the damage pattern of AA metal layer under 5mm indenter diameter is a circular shape regardless of monolithic or stack sheets, while the damage pattern of AA metal layer in the other two diameter cases shows a petaloid shape. This is mainly because a smaller tool contact surface during perforation more easily experiences from elastic bending to a whole circumferential tensile tearing. By contrast, a larger tool contact surface leads to bi-axial even multi-axial tensile tearing. Moreover, the developed analytical mode can predict the variation trends of perforation energy correctly. Our findings show that applying a metal layer to the CFRP sheet can provide a practical method to enhance the mechanical performance of existing CFRP materials.
|
|
Keywords: AA/CFRP stack sheets, Perforation, Deformation mechanism, Energy absorption.
|
Download PDF
|
|
*Corresponding author; e-mail:
|
©
2023
CSME , ISSN 0257-9731
|