Nonlinear Dynamic Analysis of Frangible Nosecap for Vertical Launch AntisubmarineRocket (VLA)

摘要

Described here is the application of a nonlinear finite element analysis (FEA)technique to predict the structural behaviors for a class of brittle materials that shows near-complete brittleness when loaded in tension, but exhibits some ductility when compressed. An ABAQUS* constitutive model, consisting of an isotropically hardening yield surface, which is active when the stress state is dominantly compressive, and an independent crack detection surface to determine if a point in the material fails by cracking in tension, is employed to simulate the failure of the brittle material. The application of the technique to determine if a potential frangible nosecap design of the Vertical Launch Antisubmarine Rocket (VIA) would break up as intended upon water impact for a given entry condition is presented as an example.