VT Mobile Aerospace Engineering

Foam-like materials have been studied extensively for applications requiring energy absorption and blast mitigation. This work analyzes the interplay between viscoplasticity—quantified by the rate-dependence and viscosity parameters—and various hardening rules for uniform density foams when they are subject to blast-like impact loads. The foam is modeled using a simple viscoplastic extension of the rate-independent elastoplastic model developed by Deshpande and Fleck and a flexible hardening rule that exhibits different qualitative hardening regimes. The constitutive model is implemented as a VUMAT in ABAQUS. The underlying elastoplastic wave mechanics under these different scenarios is also examined. The results presented here indicate a qualitative change in the foam response depending on the amount of viscoplasticity and the type of hardening behavior. Additionally, this study attempts to answer whether or not ratedependency is always beneficial for mitigation of applied loads. The results presented in this work has important implications for the design of impact-resistant foams.

Aiming at the problem of Magnetically Suspended Control Sensitive Gyroscope(MSCSG) space application, the attitude maneuvering capability of spacecraft based on MSCSG is studied. On the basis of introducing the principles of MSCSG moment output and attitude sensitivity, a spacecraft attitude dynamics model based on MSCSG is established, and the PD decoupling control rate as well as the rotor maneuvering rate are designed to realize the three-axis attitude control under the saturated state of rotor deflection. The simulation results show that under the control of a single MSCSG, the satellite is able to achieve a 10° attitude maneuver in 7 seconds under the saturated MSCSG rotor deflection. Due to the characteristics of the integrated MSCSG measurement and control, it provides a new idea for the attitude maneuvering of high-orbit satellites.

Low, slow and small UAVs are increasingly used in daily life, but most of them are in the state of black flight and uncontrolled, posing a great threat to public safety, personal safety and personal privacy; and the supervision of such targets is also a big There are many problems in the detection of such targets in complex environments. Based on this, this paper introduces the main threats of low, slow, and small UAVs, analyzes the difficulties of low, slow, and small UAV detection by radar detection means, designs a target detection process for clutter suppression technology, and verifies it through experiments, and finally Finally, we summarize the problems of the current UAV radar detection technology and propose the development trend of low, slow and small UAV target detection technology.

Introduced the typical mission requirements of Beidou short message communication technology for low-orbit remote sensing, studied the key technology of low-orbit satellite short message communication system, and proved the correctness of the designed key technology through the research on the data obtained from the actual test on orbit.

Summary: For the data protected by the IPSec protocol supported by IPv6, it is difficult to obtain the required port information when passing through the firewall. This paper proposes to configure SPD on the firewall to realize the IPSec processing of the protocol header by the firewall, thereby reducing the burden on the host; the MAC address plus link prefix information is used as a security verification method to further improve the data forwarding efficiency of general firewalls. The various methods involved in this scheme have a good technical application foundation, and the multiple technical reorganization scheme is highly achievable.