Biography

Areas of specialism

Micro-Vibration Isolation; Micro-Vibration Analysis and Testing ; Micro-Vibration Sources; Finite Element Analysis; Multi-Physics Analysis; Structural Dynamics

My qualifications

February 2018
PhD in space Engineering at the University of Surrey with a thesis entitled "Electromagnetic Shunt Damper for Spacecraft Microvibration Mitigation"
July 2013
Master's degree in Space System Engineering at the School of Aerospace Engineering (Sapienza University of Rome) with a thesis entitled "Design and analysis of a deployment system for a thin-walled composite boom"
December 2010
Bachelor's degree in Aerospace Engineering at Sapienza University of Rome

Business, industry and community links

Surrey Satellite Technology Limited (SSTL)
PhD studies in collaboration with SSTL. Worked in the company for casual labour. Currently supervising PhD students funded by SSTL.
UK Space Agency (UKSA)
PostDoc funded by the UKSA through the NSTP-3 program
European Space Agency (ESA)
PhD studies were supervised by ESA and current collaboration on the characterisation of reaction wheel micro-vibration signature

Research projects

My publications

Publications

Stabile A, Aglietti G, Richardson G, Smet G (2017) A 2-collinear-DoF strut with embedded negative-resistance electromagnetic shunt dampers for spacecraft micro-vibration, Smart Materials and Structures 26 (4) 045031 Institute of Physics
Micro-vibration on board a spacecraft is an important issue that affects payloads requiring high pointing accuracy. Although isolators have been extensively studied and implemented to tackle this issue, their application is far from being ideal due to the several drawbacks that they present, such as limited low-frequency attenuation for passive systems or high power consumption and reliability issues for active systems. In the present study, a novel 2-collinear-DoF strut with embedded electromagnetic shunt dampers (EMSD) is modelled, analysed and the concept is physically tested. The combination of high-inductance components and negative-resistance circuits is used in the two shunt circuits to improve the EMSD micro-vibration mitigation and to achieve an overall strut damping performance that is characterised by the elimination of the resonance peaks and a remarkable FRF final decay rate of ?80 dB dec?1. The EMSD operates without requiring any control algorithm and can be comfortably integrated on a satellite due to the low power required, the simplified electronics and the small mass. This work demonstrates, both analytically and experimentally, that the proposed strut is capable of producing better isolation performance than other well-established damping solutions over the whole temperature range of interest.
De Lellis Salvatore, Stabile Alessandro, Aglietti Guglielmo, Richardson Guy (2018) A Methodology for Disturbance Characterisation of Families of Microvibration Sources, Proceedings of ECSSMET 2018 ESA
Disturbances generated by reaction wheels on board the
spacecraft are among the most
substantial
. Hence they
play a crucial role when microvibration budget
has to be
assessed. This paper aims at characterising the effects of
RW on the structure by focusing on the format of the
disturbance input matrix of these components. In
particular the case of single and multiple wheel
accounted for. In the first
one
the
responses are evaluated
at some specific locations of the reaction wheel where
their disturbance is amplified, i.e. harmonics. In the
second case a more realistic scenario is considered with
several wheels to be characterised and the effects of
neglecting
some terms of the disturbance input matrix are
discussed. Finally a sensitivity analysis is carried out to
quantify in which extent changes in the input matrix can
alter the response. A preliminary methodology is then
suggested to characterise a large num
ber of wheels.
De Lellis Salvatore, Stabile Alessandro, Aglietti Guglielmo (2018) A Preliminary Methodology to Account for Satellites?
Structural Dynamics Variability in Microvibrations,
2018 AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference Proceedings American Institute for Aeronautics and Astronautics
Due to constantly increasing requirements for more precise and high-resolution instrumentations,
microvibration prediction represents an issue of growing importance. Hence the need
of reliable analysis tools which can evaluate microvibrations effects efficiently. This paper
describes how to tackle the issue of structural uncertainties in microvibration predictions. In
particular, uncertainties related to the microvibration sources are analysed as well as those
linked to the modelling of the structure. A methodology to define the worst case of vibration
produced by on board sources is presented and compared to experimental data. Additionally,
an approach to quantify the uncertainties in the Finite Element model is also described.
De Lellis S., Stabile A., Aglietti G.S., Richardson G. (2019) A semiempirical methodology to characterise a family of microvibration sources, Journal of Sound and Vibration 448 pp. 1-18 Elsevier
It is well documented that reaction wheels are among the most significant microvibration sources in space applications. These components, despite being nominally identical, can show differences in the generated signals due to manufacturing imperfections in their internal elements, such as ball bearing, internal and external race. In this article a methodology to account for those variations in microvibration predictions is proposed, aiming at generating a disturbance input matrix that encompasses the effects of a family of reaction wheels. With such a tool, it is possible to provide a more accurate microvibration budget at an early stage of the mission, reducing the uncertainty margin usually applied to quantify reaction wheel effects on the structure. As a consequence better designs are produced faster and cheaper. This allows for more flexibility in the mission design and reduces the degree of uncertainties in the predictions. Furthermore, it is shown that the proposed approach is able to characterise the effects of the entire family of wheels by considering only a limited number. The methodology is validated by assessing the microvibration excitation on different structures, including a real space structure with various reaction wheel mounting configurations.