Fatigue Crack Growth in 7050T7451 Aluminium Alloy Thick Section ...

More documents

Recommendations

Info

DSTO-TR-1477127mm Radius (5’)230mm65mm15mm6.35mmFigure 5A drawing of the specimens used in this testing programThe specimens were machined from a 5.5 inch thick 7050-T7451 aluminium alloy plate with theDSTO, AVD designation of ‘KS’ (produced by Ravenswood Aluminium Corporation,Ravenswood, West Virginia 3 ). The long axis of the specimen aligned with the rolling direction andthe width of the specimen in the rolling plane as shown, in Figure 6. This gave the coupons a grainorientation that was more resistant to fatigue crack growth than would have been the case hadthey been cut with the long axis across the plate width. The cracking in these specimens will be inthe Short/Transverse plane. The structural detail that was the subject of the previous testinggenerates cracking consistent with ‘across the plate’ specimens – cracking in theShort/Longitudinal plane, therefore the specimens tested here are not strictly representative of themould line flange of the F/A-18 bulkheads.Rolling directionT (Transverse)S (Short Transverse)L (Logitudinal)Figure 6A schematic showing the orientation of the specimens as they were cut from the plate3.3 Specimen Material PropertiesThe KS plate was certified by Ravenswood to conform to the requirements of the specificationAMS 4050E which is very similar to the McDonnell Douglas Process specification 1420. Thechemical composition specification requirements are shown in Table 1 along with the results ofanalysis of the KS plate. Table 2 shows the mechanical properties and conductivity requirementsof 7050T7451. The supplied mechanical properties and conductivity measurements are shown inTable 3 along with the measured conductivity and hardness values.3 now – Century Aluminium Company6
DSTO-TR-1477Table 1 Specification AMS 4050E – Chemical composition %.Element Min Max Analysis of KSplateZinc 5.7 6.7 6.42Copper 2 2.6 2.20Magnesium 1.9 2.6 1.99Zirconium 0.08 0.15 0.08Iron -- 0.15 0.06Silicon -- 0.12 0.03Manganese -- 0.1
Page 3: Fatigue Crack Growth in 7050T7451 A
Page 8 and 9: DSTO-TR-1477To build the required l
Page 10 and 11: DSTO-TR-1477than internal flaws. An
Page 14: DSTO-TR-1477At the surface large gr
Page 18 and 19: DSTO-TR-1477Figure 11 The fracture
Page 20 and 21: DSTO-TR-1477A (KSIF152)B (KSIF107)F
Page 22 and 23: DSTO-TR-1477life axes. The data poi
Page 24 and 25: DSTO-TR-14774. Discussion4.1 Introd
Page 26 and 27: DSTO-TR-14774.2.2 Shape of the crac
Page 28 and 29: DSTO-TR-1477poorly defined areas on
Page 30 and 31: DSTO-TR-1477Simulated flight hours0
Page 33 and 34: DSTO-TR-1477in the appropriate regi
Page 35 and 36: DSTO-TR-1477390MPa(higherslope)420M
Page 37 and 38: DSTO-TR-1477Table 9Specimen No.A co
Page 39 and 40: DSTO-TR-1477considerable concern to
Page 41 and 42: DSTO-TR-1477Barter, S. A., Fatigue
Page 43 and 44: DSTO-TR-1477126.5 41102 0.1638 0.25
Page 45 and 46: DSTO-TR-1477248.5 80743 0.1195 0.12
Page 47 and 48: DSTO-TR-147730.5 9910.1 0.0713 0.10
Page 49 and 50: DSTO-TR-1477104.5 33954 0.0733 0.08
Page 51 and 52: DSTO-TR-147743.5 14134 0.042 0.0468
Page 53 and 54: DSTO-TR-147716.5 5523.6 0.0406 0.05
Page 55 and 56: DSTO-TR-147718.5 6011 0.0264 0.0452
Page 57 and 58: DSTO-TR-147723.5 7635.6 0.0481 0.08
Page 59 and 60: DSTO-TR-1477Table A-13. Results of
Page 61 and 62: DSTO-TR-1477Table A-16. Results of
Page 63 and 64:
DISTRIBUTION LISTFatigue Crack Grow
Page 65:
Page classification: UNCLASSIFIEDDE
show all

Fatigue Crack Growth in 7050T7451 Aluminium Alloy Thick Section ...

Create successful ePaper yourself

Delete template?

Save as template?