Analisi termiche

LIST

TO DO FEM

05

22 THEORY

PLATE

23 05 PRESENTATION

COMPOSITE

05

24 A

25 HOMEWORK

05 THERMAL

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Thermal analysis and design

1. The thermal scheme: basics on the thermal problem

2. The heat conduction problem, strong and weak forms

3. The finite element modelling of thermal behaviour

4. The finite element modelling of thermoelastic problems

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

The thermal behaviour of physical systems

The compeonents of spacecraft and launchers structures are affetcted by temperature

variation that might generate problems of functionality in on board equipements and

generate thermoelastic loads. In both cases it is of paramount importance to monitor the

thermal behaviour of each hardware of the space system, assuming all the possible heat

transfer mechanisms and generation. In space mainly radiation and conduction are

considered. What is needed by system requirement for thermal problems is the capability of

keeping the prescriberd ranges of temperature without breaking or failures and without

generating excessive thermoelastic loading..

This means that by observing our physical system (our hardware, if you like) we need to

monitor its physical state in terms of temperatures and heat fluxes. It is important to

control these variables of the state of the physical system while also considering the effect

of the generated thermoelastic loads due to the presence of thermal strain produced by the

variation of temperatures with respect to a temperature reference value. 4

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

The thermal behaviour represented by the thermal scheme

OUTPUT INPUT

STRUCTURE

STRUCTURAL RESPONSE FORCING ACTIONS

A 3-dimensional system

STATE VARIABLES LOADING FUNCTIONS

characterized by:

• a GEOMETRY

• •

Displacements Volume Forces

• a MATERIAL

• •

Strain Surface Forces

• •

Stress Concentrated Forces

Physical retaltions between output • Applied Displacements

and input: •

State variables are defined as Co-actions (thermal strain)

1. MECHANICAL EQUILIBRIUM

continuous functions of the position 2. CYNEMATIC COMPATIBILITY

and time of the material point. Loading functions depend upon the

(strain in terms of

f = f(P,t) position and the time.

displacements)

3. CONSTITUTIVE RELATIONS

The structure is a material system, that is to say a solid 3D body, with a certain geometry,

Space structures 9

3 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis

Space structures 9 AA 2022/23 Prof. Paolo Gaudenzi

Contents: Thermal design and analysis