Multi-scale crack closure measurements with digital image correlation on Haynes 230
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 33
Abstract
An experimental campaign was developed to study fatigue crack growth in Haynes 230, a Ni-based superalloy. The effects of crack closure were investigated with digital image correlation, by applying two different approaches. Initially, full field regression algorithms were applied to extract the effective stress intensity factor ranges from the singular displacement field measured at crack tips. Local closure measurements were then performed by considering crack flanks relative displacements. Two points virtual extensometers were applied in this phase. Experimental results were then compared to the reference da/dN –ΔKeff curve: it was found that the correct estimation of crack opening levels shifts all the experimental points on the reference curve, showing that DIC can be successfully applied to measure crack closure effects.
Authors and Affiliations
Stefano Beretta, Silvio Rabbolini, Angelo Di Bello
Energy dissipation and storage in iron under plastic deformation (experimental study and numerical simulation)
The work is devoted to the experimental and numerical investigation of thermodynamic aspects of the plastic deformation in Armco iron. Dissipation and stored energies was calculated from processed experimental data...
Role of the microstructure on the mechanical properties of fully pearlitic eutectoid steels
This paper analyses how the microstructure of an eutectoid pearlitic steel affects its conventional mechanical properties (obtained by means of a standard tension test) and the associated micromechanisms of fract...
Fretting fatigue crack propagation rate under variable loading conditions
Fretting fatigue experiments aim to represent industrial problems and most of them endure variable loading. Being able to assess lifetime of assemblies, especially for low propagation rate conditions, is essential...
Determination of fracture mechanics parameters on a base of local displacement measurements
New experimental technique for a determination of the stress intensity factor (SIF) and T-stress values is developed and verified. The approach assumes combining the crack compliance method and optical interferomet...
Static and fatigue experimental tests on a full scale fuselage panel and FEM analyses
A fatigue test on a full scale panel with complex loading condition and geometry configuration has been carried out using a triaxial test machine. The demonstrator is made up of two skins which are linked by a&nbs...