title: Effects of neck damping properties on brain response underimpact loading.
abstract: In this paper, head-neck boundary conditions and modeling of the head are studied circumspectly. The neck is modeled using discrete elements and the head model is three-dimensional. In the study presented here, a viscoelastic foundation (i.e., foundation defined by both springs and dampers) concept is introduced to simulate the head-neck boundary conditions during the impact load to the head. Time histories of the brain response in finite element head models with a viscoelastic neck are compared with the corresponding solutions of finite element head models with an elastic neck, and without a neck. It is observed that the magnitude of peaks in the brain's response time histories, at a later stage (i.e., 6 to 15 ms) of the simulation, decreases when dampers are induced to the elastic neck. A parametric study is also conducted to examine the brain response while varying different damping coefficient values for the neck. The magnitude of peaks in the brain's response time histories for models with different neck damping coefficients is observed to maintain some form of proportionality. In other words, the magnitude of peaks in the brain's response time histories decreases with an increased damping coefficient of the neck at the later stage of the simulation (i.e., 6 to 15 ms). From the outcomes of this study, it can be determined that the head-neck boundary conditions during head impact loading are important for studying the brain's response at the later stages of the head impact.
authors.affiliation: Department of Mechanical Engineering, North Dakota State University, Fargo, ND, 58108-6050, USA.
authors.forename: V
authors.initials: V
authors.lastname: Dirisala
authors.forename: G
authors.initials: G
authors.lastname: Karami
authors.forename: M
authors.initials: M
authors.lastname: Ziejewski
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D001930:Brain Injuries / Q000503:physiopathology*; D055119:Elastic Modulus / Q000502:physiology; D020342:Finite Element Analysis; D006257:Head / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007427:Intracranial Pressure; D008297:Male; D008954:Models, Biological; D009333:Neck / Q000033:anatomy & histology / Q000502:physiology; D013314:Stress, Mechanical; D014783:Viscosity
keywords: finite elements; head modeling; impact loading; intracranial pressure; shear strain; shear stress; viscoelastic foundation