持续性高过载下人脑的多孔弹性响应

Sustained high overloads often acting during aerospace flights can significantly affect the passenger brain function dependent on the mechanical behavior of brain tissue and highly correlated with load characteristics. To predict the mechanical responses of human brain under sustained high overloads, the poroelastic constitutive model was adopted to characterize the mechanical behaviors of brain tissue. Built on an idealized 1D multi-layer structural model for human heads, the poroelastic control equation and the state transfer matrix for the brain tissue were derived. Through the Laplace transform and its inverse transform, the spatiotemporal distribution of the intracranial fluid pressure, the intracranial fluid seepage velocity, the brain tissue effective stress, and the brain tissue displacement were obtained. The results indicate that, the intracranial fluid infiltration has a significant impact on the responses of the brain tissue under sustained high overloads. The present work emphasizes the appropriateness and necessity of using poroelastic constitutive models to describe the mechanical behavior of brain tissue, providing important theoretical insights for the study of brain biomechanics under extreme load conditions.