Thermo-Mechanical Structural Optimisation of a Chemical Propulsion Satellite Thruster Using Lattice Structures

Small satellite space thrusters are designed to provide force for short time periods. • New generation of thrusters will be made with High Entropy Alloy (HEA) materials. • Predicting damage initiation for this kind of metallic structure subjected to thermal shock is of fundamental importance. • The preliminary thermal-stress analysis is mandatory in order to understand the complex failure mechanism of the space thruster. • An optimisation analysis of the material distribution along the combustion chamber thickness can lead to an improvement of the thermal-stress response

Heat conduction and thermal stress analysis of laminated composites by a variable kinematic MITC9 shell element

The present paper considers the linear static thermal stress analysis of composite structures by means of a shell finite element with variable through-thethickness kinematic. The temperature profile along the thickness direction is calculated by solving the Fourier heat conduction equation. The refined models considered are both Equivalent Single Layer (ESL) and Layer Wise (LW) and are grouped in the Unified Formulation by Carrera (CUF). These permit the distribution of displacements, stresses along the thickness of the multilayered shell to be accurately described. The shell element has nine nodes, and the Mixed Interpolation of Tensorial Components (MITC) method is used to contrast the membrane and shear locking phenomenon. The governing equations are derived from the Principle of Virtual Displacement (PVD). Cross-ply plate, cylindrical and spherical shells with simply-supported edges and subjected to bi-sinusoidal thermal load are analyzed.Various thickness ratios and curvature ratios are considered. The results, obtained with different theories contained in the CUF, are compared with both the elasticity solutions given in the literature and the analytical solutions obtained using the CUF and the Navier’s method. Finally, plates and shells with different lamination and boundary conditions are analyzed using high-order theories in order to provide FEM benchmark solutions

Low cycle fatigue predictions of a space thruster built with a new refractory high entropy alloy

Directional thrusters are designed to provide force for short time periods. • New generation of thrusters could be made using a High Entropy Alloy (HEA). • Predicting fatigue damage initiation for this kind of metallic structure subjected to cyclic loads is important. • Design for fatigue resistance relies on empirical with high financial costs. • Unified Mechanics Theory (UMT) will be used to predict fatigue damage initiation of a material system without having experimental fatigue dat

Dynamics around the binary system (65803) Didymos

Didymos and Dimorphos are primary and secondary, respectively, asteroids who compose a binary system that make up the set of Near Earth Asteroids (NEAs). They are targets of the Double Asteroid Redirection Test (DART), the first test mission dedicated to study of planetary defense, for which the main goal is to measure the changes caused after the secondary body is hit by a kinect impactor. The present work intends to conduct a study, through numerical integrations, on the dynamics of massless particles distributed in the vicinity of the two bodies. An approximate shape for the primary body was considered as a model of mass concentrations (mascons) and the secondary was considered as a massive point. Our results show the location and size of stable regions, and also their lifetime