Luca Lampani

Finite element analysis of delamination of a composite component with the cohesive zone model technique

Purpose – The purpose of this paper is to assess a numerical tool to simulate and predict the onset and the propagation of the delaminations in a composite structure.Design/methodology/approach – The approach to the work is done through the cohesive zone model technique applied to the finite element method.Findings – Double cantilever beam, end notched flexure and mixed mode bending tests have been performed and correlated to benchmark cases, in order to validate the procedure. Numerical test campaign on specimens of the skirts with delaminations has been performed to analyze the behaviour under compressive load and the buckling.Originality/value – This tool is applied to the study of the behaviour of some components in carbon/epoxy composite of a space structure in which one or more delaminations are eventually present following impact damage or manufacturing process. The components in particular are the boosters skirts of a small class launcher, subjected to a compressive load.

3D Finite Element Analyses of Multilayer Dielectric Elastomer Actuators with Metallic Compliant Electrodes for Space Applications

A special actuator device with passive sensing capability based on dielectric elastomer was studied and specialized to be used in space applications. The work illustrates the research project modeling procedure adopted to simulate the mechanical behavior of this material based on a finite-element theory approach. The Mooney-Rivlin’s hyperelastic and Maxwell’s electrostatic models provide the theoretical basis to describe its electromechanic behavior. The validation of the procedure is performed through a numerical—experimental correlation between the response of a prototype of actuator developed by the Risø Danish research center and the 3D finite-element model simulations. An investigation concerning a possible application in the space environment of dielectric elastomer actuators is also presented.

Smart thermal protection systems

Thermal protection technologies based on ablators and segmented ceramic heat shields have been developed in Europe with the last two decades. The successful re-entry flights of HUYGENS, ARD and MIRKA indicate the progress achieved up to now. To stimulate the identification and assessment of novel alternatives to conventional thermal protection materials and constructions an exploratory study on Smart TPS has been launched by ESA. This new point-of-view in the field of winged re-entry and launcher technology resulted initially in 35 ideas. Subsequent concept drafting reduced this number to 11 feasible concepts and a few further developments put on a technology watch list. This paper presents an overview and brief discussion of the most relevant Smart TPS materials and concepts identified and elaborated in this exploratory activity which will be completed by some breadboard testing.