Apresentao do PowerPoint

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TESTING PROGRAMME OF IDMEC
Paulo M S T de Castro, Fernando M F Oliveira
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outline

• the objective of the testing is to contribute to
  the understanding of EIFS
• using scanning electron microscopy (sem) and
  other techniques for the study of early crack
  growth stages (sem will be conducted on specimens
  broken after certain number of cycles), in both
  normal and cold worked open hole specimens
  supplied to IDMEC by DASA, comparing test results
  and analytical predictions for simple
  configurations, and
• to contribute to the experimental determination
  of a reliable EIFS distribution, using specimens
  of the type lap splice with 3 rivet rows and 1
  rivet column to be supplied by NLR (this will be
  part of the testing programme coordinated by NLR).

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simple open-hole specimen
 these specimens will be supplied to IDMEC by
DASA   material 2024 T3 notch type centre
open hole hole diameter 4.8mm width
25mm thickness 2.0mm   batch 1 simple open
hole (25 specimens) batch 2 cold-worked open
hole (25 specimens) (email from H Trey of the
21st September 2001)
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simple open-hole specimen
data for short crack propagation, including small
crack propagation, micro-fractographic
investigation using scanning electron microscopy,
and residual stress field estimation.   stress
levels to be determined, but in the range
80-130 MPa (to promote coordination and
complementarity with experimental work of DASA,
likely stress levels will be 90MPa, 105 MPa and
120 MPa).
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simple open-hole specimen
geometry of DASA specimens to be tested by IDMEC
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lap splice with 3 rivet rows and 1 rivet column
these specimens will be supplied to IDMEC in the
context of testing coordinated by NLR   type of
test Tension fatigue test R-value Fmin/Fmax
0.05 material 2024 T3 Alclad sheets thickness
1.2 mm riveting force according to industrial
standards stress level 120 MPa
(120201.22.88 kN) number of tests
50 (email of M Kooloos of the 1st October 2001)
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lap splice with 3 rivet rows and 1 rivet column

• geometry
• width corresponding to rivet pitch of a fuselage,
  i.e. 20 mm length 260 mm, with a 60 mm overlap
• load perpendicular to the rolling direction
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• test procedure
• In the case of narrow riveted lap joint specimens
  with one rivet there will be hardly any
  measurable crack growth one data point on the
  P-S-N curve per specimen (i.e. number of cycles
  to initiation and the corresponding stress level)
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• criterion
• fatigue life defined as specimen failure

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lap splice with 3 rivet rows and 1 rivet column
geometry of specimens to be tested by IDMEC in
the testing programme coordinated by NRL