Engineering topics

Daniel Wentzel

Publications and source records attributed to Daniel Wentzel.

2 records

NASA NTRS2018

Electrical Properties of Unidirectional Carbon Fiber Reinforced Epoxy-Graphene Composites

This paper aims at establishing connections between electrical resistivity and stresses in carbon fiber reinforced epoxy-graphene composites. To avoid the interconnection of multiple parameters, we examined composite specimens consisting of a single strand or tow (12,000 carbon fiber filaments) embedded in an epoxy matrix containing up to 1.0 wt% of graphene (TG679) particles. The specimens show resistance increase with the tensile stress. The characteristic of the dependence varies with the content of graphene particles, tending to be linear as the percentage of graphene content increases. We did not observe any significant changes in the ultimate strength of the composite with an increase of the graphene particles concentration.

Daniel Wentzel↗

NASA NTRSDate not supplied

Engineering Launch Methods for Non-Spherical Hypervelocity Projectiles

The use of carbon-fiber-reinforced polymer (CFRP) in modern satellites has led to a significant amount of space debris, including fragments of CFRP and high-density metals such as steel and copper, produced during catastrophic breakup events. To address this issue, NASA's White Sands Test Facility (WSTF) has been developing the capability to launch "flake-like" and long "needle-like" projectiles. WSTF tested projectiles with different length-to-diameter ratios (L/D), impacting aluminum Whipple shields with thermal blankets on the outer surface, at velocities exceeding 6 km/s. The results of the study suggest that launching and imaging shaped projectiles at high velocities is feasible. Ongoing research is now focused on improving the techniques for launching and imaging shaped projectiles under hypervelocity conditions.

Engineering↗