Process Optimisation: Notching

Automation for Spacecraft

Payload under Sine Response

Antonio Di Carlo

Engineer R&D

8-9 Nov. 2011

8-9.11.2011 RUAG Group company, Antonio Di Carlo 2

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

Abstract

Notching is a well known topic in the design of space structures, both at spacecraft and at equipment level.

The aim of notching is to reduce the input during qualification sine vibration tests in order not to exceed

either the maximum quasi-static interface loads at the shaker interface (primary notching) and/or to limit

the response of some of the internal parts of the test item (secondary notching). The notched input profiles

used for the qualification testing need to be approved, prior to the test, by the launching authority after a

coupled load analysis.

For spacecraft structures, the notching process is a complicated exercise involving a lot of equipment units

within the spacecraft and different notching criteria which can differ from one unit to the other.

This presentation gives an overview on the HyperWorks notching tool developed by RUAG Space and

ALTAIR Engineering in the frame of the Small Geo programme, a geostationary spacecraft platform for

commercial application.

F. Mouriaux ; A. Di Carlo

RUAG Space Zürich Schaffhauserstrasse 580 CH-8052 Zürich Tel.:+00 41 44 306 22 11

8-9.11.2011 RUAG Group company, Antonio Di Carlo 3

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

INTRODUCTION

What is notching?

Notching is the limitation of the

input during the sine qualification

test

Primary notching

Primary notching is the limitation

based on the forces and moments

at the interface to the launcher

Secondary notching

With secondary notching, the input at the launcher interface is limited in order not to exceed the specific Unit

qualification envelope.

Secondary notching applies on top of the primary notching

REMARK

The notched input profile used for the qualification testing needs to be approved, prior to the test, by the launching

authority through a coupled load analysis.

8-9.11.2011 RUAG Group company, Antonio Di Carlo 4

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

PROBLEM DEFINITION

Primary notching based on multiple launchers (Ariane 5, Atlas, Soyuz, Proton, Sea Launch…)

Multiple secondary notching criteria

Acceleration: Limitation of the acceleration of a specific point of a Unit (identified by a FEM node).

Individual I/F Force: Limitation of the reaction force or moment at a specific interface point of a Unit.

Resultant I/F Force: Limitation of the resulting force or moment at the mounting plane of a Unit.

Different types of secondary notching criteria can be applicable simultaneously to a Unit.

Large number of Units (electronic boxes, tanks, antennas, solar arrays, reflectors…).

Large number of data due to the nature of the analysis

sine response with high sampling rate to cover individual modes

consideration of amplitude and phase information

8-9.11.2011 RUAG Group company, Antonio Di Carlo 5

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

Typical Unit Acceleration Qualification Envelope to be used for secondary notching

8-9.11.2011 RUAG Group company, Antonio Di Carlo 6

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

Typical Unit Force Qualification Envelope to be used for secondary notching

8-9.11.2011 RUAG Group company, Antonio Di Carlo 7

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

Definition of the folders containing launcher and equipment

data (csv files)

8-9.11.2011 RUAG Group company, Antonio Di Carlo 8

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

Definition of the launcher input data:

Nominal Sine Input

Quasi-Static Accelerations

Angle Steps

8-9.11.2011 RUAG Group company, Antonio Di Carlo 9

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

Definition of the equipment allowable data:

Sine Qualification Level

Node Range

Unit Mounting Plane

8-9.11.2011 RUAG Group company, Antonio Di Carlo 10

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

Definition of the launchers to be evaluated. At the end an

envelope input profile is provided

8-9.11.2011 RUAG Group company, Antonio Di Carlo 11

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

Definition of the NASTRAN Input files (f06 and pch)

Definition of the file to store the envelope profile

8-9.11.2011 RUAG Group company, Antonio Di Carlo 12

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

8-9.11.2011 RUAG Group company, Antonio Di Carlo 13

Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response IMPLEMENTATION IN HYPERWORKS

Dedicated GUI

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Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

CONCLUSION

Automation and standardisation of the notching

process

Improvement of process robustness and efficiency

Quick assessment of the System performance

Easy reporting (direct export of curves to Word

document)

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Process Optimisation: Notching Automation for

Spacecraft Payload under Sine Response

AKNOWLEDGMENT

Sudhir Padaki Project Engineer Aero ALTAIR Engineering (Product Design)

Ramona Schwarz Senior Software Engineer ALTAIR Engineering (Product Design)

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Thank you for your attention!