Non-linear hysteretic damping of graded nanocomposite honeycomb structures for vibration-optimised design of artifical space satellites (HYST)

Project: Research project

Grant Program

ORAU Grant

Project Description

Artificial space satellites are subjected throughout their lifetime to various vibrations, ranging from severe vibrations during the various launch stages, to vibrations induced by orbital corrections/ adjustments, to microvibrations caused by the operation of mechanical drives and mechanisms while in orbit. In all cases, the sensitive on-board equipment must be protected and isolated from such vibrations to preserve its integrity and accuracy. Microvibrations in particular, if not drastically dampened, can persist for significant time intervals after excitation and significantly affect the accuracy of measuring instruments during operation, thus impairing the functionality and reliability of the satellite. Given the poor vibration damping properties of existing metal space-frame (typically aluminium alloy) solutions, the state of the art is to insert passive elastomeric damping elements or active vibration cancelling elements at critical nodes in the structure (discussed extensively in [1]), which however only partially resolves the vibration issue, creates a reduction in stiffness, increases the structural complexity, and introduces points of failure, thereby lowering system resilience: The performance of elastomeric joints deteriorates in space, due to their low intrinsic resistance to particulate and electromagnetic radiation, and the complex active control systems are susceptible to failure over multi-year mission periods.
To address this problem, the HYST project will enable the design and construction of a lightweight high-stiffness monolithic architecture with superior damping and stiffness-to-weight characteristics compared to existing passively damped metal space-frame and composite monocoque architectures, by introducing, modelling and validating a multiscale honeycomb topology using directionally aligned CNT-reinforced PEEK. This high stiffness space-grade material has been developed and validated for use in artificial satellite structures by the PI and HYST partners in a prior project with the European Space Agency and subsequent FP7 project M-RECT. Damping in particular will be achieved at no cost to stiffness, by exploiting the non-linear stick-slip dissipation mechanisms at the CNT-PEEK interfaces and the superior damping properties of the PEEK matrix itself. In addition, the honeycomb topology will be spatially graded using a stiff skin-compliant core topology (of locally selectable stiffness) to allow, among other benefits, optimisation of local mechanical properties and isolation of micro-vibrations within frequency-tuned damping loci effectively utilising large parts of the structure to dissipate the vibration energy instead of concentrated and inefficient (passive or active) damping elements. This will result in a much higher structural utilisation (structural weight reduction of 15-25%), while maintaining or surpassing the passive damping capability of current architectures.
Short titleHYST
StatusActive
Effective start/end date1/1/1812/31/21

Fingerprint

Honeycomb structures
Vibrations (mechanical)
Nanocomposites
Damping
Satellites
Stiffness
Polyether ether ketones
Topology
Mechanical drives
Stick-slip
Metals
Electromagnetic waves
Aluminum alloys
Skin
Orbits
Control systems
Mechanical properties
Composite materials