Whole document - Les Missions Scientifiques du Centre National d ...

PRO.LB.0.NT.003.ASC Issue. 6 rev. 3 Page: 3.21
PL - 4.2.5 - 3
The following definitions shall be applied:
Qualification loads = 1.25 x Flight limit loads except for ground handling where:
- qualification loads = 2 x Flight limit loads for nominal analysis and
- qualification loads = 1.5 x limit loads for fail safe analysis (where 1.5 corresponds to the dynamic
factor due to the loss of one handling point).
Sizing loads = JY (or JU) x Qualification loads
The safety margin is defined as follows :
where :
σ admissible
S.
M.
= −1
σ
calculated
the admissible stress is the yield (respectively ultimate) stress when estimating the safety margin wrt yield
(respectively ultimate).
the admissible stress for single points failure pieces of hardware shall be "A" type values (99% probability with
a 95% confidence level),
the admissible stress for redundant pieces of hardware shall be "B" type values (90% probability with a 95%
confidence level),
the calculated stress is the qualification stress times the yield (respectively ultimate) safety factor.
PL - 4.2.5 - 4 a
All safety margins shall be positive:
• local buckling criterion: there shall be no buckling under qualification loads
4.2.5.3 Notching philosophy
PL - 4.2.5 - 5
Notching at payload level is allowed during sine vibration test in order not to exceed, at the
platform/payload interface, the Quasi-Static equivalent loads (resultant forces and moments at the
geometrical centre of the interface points) after Satellite Contractor agreement
Notching at payload units level is forbidden.
PL - 4.2.5 - 6
For notching during random vibration tests, the Payload Supplier shall contact either ALCATEL SPACE or
CNES.
4.2.5.4 Structural mathematical models
The requirements for the quality of mathematical models, numbering ranges and interface point locations are given
in section 4.6.1.
All right reserved. ALCATEL SPACE /CNES
Passing and copying of this document, use and communication of its content is not permitted without prior written authorization.