Personal tools
Home → 10th International LS-DYNA Conference → Soft Soil Impact Testing and Simulation of Aerospace Structures

restrict search to current section
For a simple text search, enter your search term here. Multiple words may be found by combining them with AND and OR. The text in this field will be matched with items' contents, title and description.

 

Soft Soil Impact Testing and Simulation of Aerospace Structures

Contributors: Edwin L. Fasanella, Karen E. Jackson, Sotiris Kellas - NASA Langley Research Center, VA

In June 2007, a 38-ft/s vertical drop test of a 5-ft-diameter, 5-ft-long composite fuselage section that was retrofitted with a novel composite honeycomb Deployable Energy Absorber (DEA) was conducted onto unpacked sand. This test was one of a series of tests to evaluate the multi-terrain capabilities of the DEA and to generate test data for model validation. During the test, the DEA crushed approximately 6-in. and left craters in the sand of depths ranging from 7.5- to 9-in. A finite element model of the fuselage section with DEA was developed for execution in LS-DYNA®, a commercial nonlinear explicit transient dynamic code. Pre-test predictions were generated in which the sand was represented initially as a crushable foam material MAT_CRUSHABLE_FOAM (Mat 63). Following the drop test, a series of hemispherical penetrometer tests were conducted to assist in soil characterization. The penetrometer weighed 20-lb and was instrumented with a tri-axial accelerometer. Drop tests were performed at 16- ft/s and crater depths were measured. The penetrometer drop tests were simulated as a means for developing a more representative soil model based on a soil and foam material definition MAT_SOIL_AND FOAM (Mat 5) in LS- DYNA. The model of the fuselage with DEA was re-executed using the updated soil model and test-analysis correlations are presented.

SimulationTechnology(5)-2.pdf — PDF document, 4049Kb