Literature Survey of Airborne Vehicles Impacting with Water and Soil: Head Injury Criteria and Severity Index Development of Computer Program KRASH.

摘要

This report describes a two part study to identify KRASH code requirements for analyses of: Structure/terrain interaction; Head/structure Interaction. The literature survey of water and soil impact methodology is presented. The reports are reviewed with regard to incorporation of code modifications to program KRASH. A total of 28 water impact reports were reviewed. In the area of water impact, the representation of a transport airplane lower fuselage as a wedge-shaped planing surfaced is discussed. A relationship is developed between vertical force and depth of fuselage penetration. Forty soil impact related reports were reviewed in the survey. For soil impact the two potential approaches described include: Empirical definition of soil pressure versus depth. Theoretical definition of soil as a viscoelastic medium. For the head/structure impact assessment, the Head Injury Criteria (HIC) and Severity Index (SI) calculations are added to program KRASH. The approach, equations, and flow diagrams associated with a simple, single degree-of freedom model of a mass impacting a surface with a given velocity is described.... Occupant injury assessment, HIC, SI, Water impact, Soil impact, Analysis, KRASH.