Composite Materials Engineer, NASA Marshall Space Flight Center, AL
Design Engineer, International Construction Equipment, Matthews, NC
Pages: 15 Published: Jan 2002
The need for a static test method for modeling low-velocity foreign object impact events to composites would prove to be very beneficial to researchers because much more data can be obtained from a static test than from an impact test. In order to examine if this is feasible, a series of static indentation and low velocity impact tests were carried out and compared. Square specimens of many sizes and thickness were utilized to cover the array of types of low velocity impact events. Laminates with a π/4 stacking sequence were employed because this is by far the most common type of engineering laminate. Three distinct flexural rigidities under two different boundary conditions were tested in order to obtain damage due to large deflections, contact stresses and to examine if the static indentation-impact comparisons are valid under the spectrum of damage modes that can be experienced. Comparisons between static indentation and low velocity impact tests were based on the maximum applied transverse load. The dependent parameters examined included dent depth, back surface crack length, delamination area and to a limited extent, load-deflection behavior. Results from this particular study showed that no distinct differences could be seen between the static indentation tests and the low velocity impact tests.
composites, static indentation, impact, transverse loading rate
Paper ID: STP10634S