In this experimental work, we study the viscoelastic behaviour of in vitro brain tissue, particularly the white matter, under oscillatory shear strain. The selective vulnerability of this tissue is the anisotropic mechanical properties of theirs different regions lead to a sensitivity to the angular shear rate and magnitude of strain. For this aim, shear storage modulus (G') and loss modulus (G'') were measured over a range of frequencies (1 to 100 Hz), for different levels of strain (1 %, to 50 %). The mechanical responses of the brain matter samples showed a viscoelastic behaviour that depend on the correlated strain level and frequency range and old age sample. The samples have been showed evolution behaviour by increasing then decreasing the strain level. Also, the stiffness anisotropy of brain matter was showed between regions and species.

Aluminium and layered composite structures currently play a crucial role in the aviation sector. These structures may be susceptible to inadvertent impacts from several sources. Low-velocity impact is a type of unintended aggression that causes severe harm to composite materials and can greatly diminish their residual resistance. This research presents a novel stack of unconventional hybrid laminates aimed at improving both stiffness and elasticity through a multi-material design. We focus on analyzing the main factors responsible for impact damage in hybrid structure. Tie contact were used between plies of the composite plate in all models. Using the HASHIN criterion, we analyze the impact velocity, impact sequence, composite thickness, impact energy level, impact efforts, and damaged zones in the composite, matrices, and fibers. The primary results indicate that both impact energy and composite thickness have a substantial influence on the energy absorbed by the composite and the impact exerted in the affected area.