Damage behavior and failure mechanism of composite sandwich panel subjected to localized impact: A comprehensive study.

• A localized impact framework for full-scaled composite sandwich panel is developed and validated with test data. • The nonlinear shear response of CFRP woven fabric for simulation usage is calibrated by original cyclic shear test data to guarantee computational accuracy. • The damage and energy absorption mechanisms of different impact energy levels are comprehensively analyzed. • The effects of core height, facesheet stacking sequence and impact angle are explored regarding impact scenarios with perforation damage. Composite sandwich structure with large in-plane dimension is frequently used in high-performance fields. However, the behavior of such structure subjected to low-velocity impact possesses a localized damage characteristic. The objective of this paper is to systematically investigate the influence of impact energy and structural parameters on the damage behavior and failure mechanism of full-scaled composite sandwich panels under localized impact. Tests are carried out by impacting at the middle of the specimens with various energies. A finite element model with localized impact framework, considering complicated damage mechanisms, is developed to predict the impact responses, failure patterns, and energy absorption. The validation of the framework is achieved by comparing numerical results with experimental data. Moreover, a comprehensive parametric analysis is conducted with focus placed on the impact energy, foam-core height, stacking sequences of the laminated facesheets, and angle of impact trajectory. The results indicate that localized structural damage behavior varies with impact energy, foam-core height and impact angle, while stacking sequences of facesheet have little effect on the impact resistance of the sandwich panel. The foam core dominates the energy absorption especially in the case with perforation damage. The reported results may be useful in safety design and maintenance. [ABSTRACT FROM AUTHOR]