- Prior coursework in solid mechanics and structural analysis

- Knowledge of materials science (metals, composites, advanced materials)

- Basic understanding of spacecraft systems and orbital environment

- Familiarity with finite element analysis (FEA) tools

This module offers an in-depth examination of spacecraft structural behaviour and analysis methodologies, with a particular emphasis on the application of the finite element method (FEM). The syllabus encompasses the complete spectrum of spacecraft loading conditions, including quasi-static, acoustic, random vibration and shock environments, as well as the structural implications of the space environment. Core structural theories are developed for bars, trusses, beams, plates, shells and sandwich configurations, extending to axisymmetric, isoparametric and three-dimensional finite elements. Further topics include thermal stresses, spacecraft–launcher coupled loads, deployable structures and mechanisms, and materials for spacecraft applications, with dedicated coverage of polymeric composites and associated failure criteria. The module also introduces structural health monitoring technologies and nonlinear FEM analysis. Throughout the course, students engage with progressively complex modelling exercises, culminating in the definition, development and verification of finite element models for the final assessment.

- Understand typical spacecraft design requirements and structural configurations

- Determine the satellite’s mechanical environment under various loading conditions (e.g., sinusoidal vibrations, acoustic loads, shocks)

- Describe fundamental concepts of bending, shear and torsion analysis

- Provide an overview of static and dynamic analysis for spacecraft structures

- Analyse the structural effects of the space environment on Earth-orbiting satellites

- Understand test verification approaches of spacecraft structures

- Demonstrate an understanding of the fundamental concepts of the finite element method (FEM) for spacecraft structures using ANSYS software

The teaching methodology / workload is as follows:

- 35 hours of theory of spacecraft structures: theoretical topics will be covered, supported by practical problem-solving (3.9 CFU)

- 33 hours of theory of FEM for structural problems (3.7 CFU)

- 13 hours of FEM tutorials: largely dedicated to learning the ANSYS Mechanical APDL software (1.4 CFU)

Lecture will be both in presence (at Taranto) and online for UniSalento’s students using the MS Teams link provided by the Module Leader.

Theoretical lectures will be supported by teaching aids (slides, etc.) and practical examples using software (MATLAB and ANSYS) on Personal Computers (PCs)

Each student is advised to have a laptop on which the software (MATLAB and ANSYS) will be installed

Final summative examination will be 100% (no coursework)

The examination consists of two parts:

- Part 1 to be completed in 2 hours with no consultation of books, lecture slides, etc…

It consists of:

2 open questions about the theory

2 numerical problems to be solved using calculators

- Part 2 consisting of an oral PowerPoint presentation of the proposed FEM model (15 minutes)

Note: You can use calculators for Part 1.

Formative assessment during the course via tutorials and other learning activities

Lecture 01

- Introduction to spacecraft structures. Introduction to spacecraft loads analysis and structural dynamics. Spacecraft structural configurations. Typical launch vehicle structures. Loads cycle.

- Introduction to finite element method. Spring element. Direct and iterative numerical methods for linear systems of equations.

 

Lecture 02

- Sources of structural loading. Sources of structural loading for design loads cycle. The launch loads environment. Micro-vibrations, quasi-static loads and sinusoidal loads. Loads analysis for single degree of freedom (SDOF) systems. Lift-off and acoustic loads.

- Bar and truss elements. Stiffness matrix of the bar element oriented in plane and in the 3D space.

 

Lecture 03

- Bending of beams. Geometric properties of solid beams. Thin-walled approximation and bending of thin-walled section beams.

- Beam element. Stiffness matrix of the beam element oriented in plane and in the 3D space. Stiffness matrix of the beam element subject to torsions.

 

Lecture 04

- Shear and torsion of beams. Flexibility matrix of cylinders and cones. Shear in thin-walled section beams. Shear centre. Torsion of thin-walled section beams.

- Plane element. FEM formulation for ‘plane stress’ and ‘plane strain’ elements. Stiffness matrix of the triangular element CST and LST. Stiffness matrix of the quadrilateral element Q4. ‘Shear Locking’ effect.

 

Lecture 05

- Sandwich structures, inserts and joints. Sandwich structures, inserts and joints in sandwiches.

- Axisymmetric elements. Verification and validation of FEM, practical considerations in FEM modelling.

 

Lecture 06

- Structural effects of space environment. Vacuum, thermal radiation, modes of thermal energy transfer, thermal control systems, charged–particle radiation, micro-meteoroids and space debris, hypervelocity impact protection systems.

- Isoparametric formulation. Jacobian matrix e Gaussian quadrature rule. Introduction to the Patch Test. Stiffness matrix of 3D elements.

 

Lecture 07

- Spacecraft random loads and shocks. Broadband random loads, load analysis for base driven random vibrations, sound pressure level, shoch response spectrum, spacecraft launch vehicle separation systems and isolators.

- Plate and shell elements. Kirchhoff and Reissner–Mindlin theories. Stiffness matrix of plate and shell quadrilateral element.

 

Lecture 08

- Test verification of spacecraft structures. Prototype vs. Proto-flight approach. Testing of spacecraft structures and data analysis tools for shock. Notching.

- Dynamic equilibrium equations for FEM. Hamilton’s Principle. Modal and transient analysis. Methods of direct numerical integration. Mass matrix of diverse elements.

 

Lecture 09

- Spacecraft deployable structures and mechanisms. Deployable boom and masts, deployable structures, spacecraft mechanisms used during launch and commissioning.

- Introduction to reduction methods for FEM and the problem of thermal stresses. Modal effective mass for Multi Degree of Freedom (MDOF) system. Spacecraft / Launcher Coupled Loads Analysis. Formulation of the FEM problem of thermal stresses.

 

Lecture 10

- Composite materials for Spacecraft Applications. Classification of composites, micro-mechanics model for polymer matrix composites, plane stress constitutive relations for the composite lamina.

- Introduction to FEM analysis for polymeric composite materials. Classical and first order laminated plate theory, formulation of laminated shell elements, failure criteria for continuous fibre reinforced composites.

 

Lecture 11

- Introduction to Structural Health Monitoring systems with focus on spacecraft applications. Multifunctional lightweight composites, SHM systems for damage diagnosis and prognosis, energy harvesting technologies.

- Introduction to nonlinear FEM analysis. Solutions methods in nonlinear FEM, buckling and plastic analysis.

 

Lecture 12

- Tutorial of nonlinear FEM model.

- Wijker, J. J. Spacecraft structures, 2008, Springer Science & Business Media.

- Sarafin, T. P., & Larson, W. J. Spacecraft structures and mechanisms. From concept to launch, 1995, Space Technology Library, Springer New York.

- Liu, G.R. and Quek, S.S., 2013. The finite element method: a practical course. Butterworth-Heinemann.

- Zienkiewicz, O.C. and Taylor, R.L., 2005. The finite element method for solid and structural mechanics. Elsevier.