Analysis of Water Drop Erosion Mechanisms in Infrared-Transparent Materials Using Microphysical Fracture Models.

摘要

A theoretical program based on numerical simulations was conducted to investigate the response of infrared-transparent window materials (zinc selenide and zinc sulfide) to subsonic impacts (730 and 1120 fps) of water drops (1 and 2 mm diameter). The approach is based on an analytical loading model of water drop impact and subsequent numerical code solutions of window response using a micro-mechanical crack propagation model. An analytical model has been developed to prescribe the pressure loading on the front surface of brittle targets during subsonic water drop impact. This model is a theoretical fit to numerical code results in a form which is consistent with physical assumptions concerning water drop impact. Due to the spherical geometry of the drop, an off-axis peak pressure occurs at early times which is greater than the 1-D Hugoniot value by about a factor of two.