Fatigue properties of monolithic and metal-laminated aluminium open-hole specimens
Version of Record online: 16 OCT 2008
© 2008 The Authors. Journal Compilation © 2008 Blackwell Publishing Ltd.
Fatigue & Fracture of Engineering Materials & Structures
Volume 31, Issue 10, pages 911–917, October 2008
How to Cite
LANCIOTTI, A. and POLESE, C. (2008), Fatigue properties of monolithic and metal-laminated aluminium open-hole specimens. Fatigue & Fracture of Engineering Materials & Structures, 31: 911–917. doi: 10.1111/j.1460-2695.2008.01280.x
- Issue online: 23 OCT 2008
- Version of Record online: 16 OCT 2008
- Received in final form: 23 July 2008
- 2024 T3 aluminium alloy;
- hole deburring;
- metal laminates
The results of fatigue and crack propagation tests carried out on dog-bone specimens made of 2024-T3 are described. Two types of specimens were investigated: the first was machined from a 1.27-mm-thick sheet, while the second was machined from a bonded metal-laminated sheet, made of four 0.3-mm-thick layers. Crack propagation tests confirmed the high resistance of metal-laminated sheets to the propagation of fatigue cracks, compared to monolithic sheets, once again. At the same time, standard fatigue tests, carried out up to the final failure of the specimens, demonstrated a comparable fatigue resistance of monolithic and laminated specimens. As a consequence, it can be concluded that fatigue cracks nucleated earlier in the metal-laminated specimens, compared to the monolithic ones, but propagated more slowly. This behaviour was attributed to the presence of sharp edges in the inner laminas of metal-laminated materials which cannot be eliminated by deburring. Additional tests were carried out on monolithic specimens containing burrs and sharp edges at the holes. These specimens were drilled and reamed after stacking and pressing them to form a package. The specimens were fatigue tested without deburring the holes. A decrease in the fatigue resistance was observed. The formation of burrs and sharp edges was additionally promoted by inserting plastic foils between the specimens during the machining operations. Fatigue resistance of these specimens is progressively lower.