Dynamic Crack Tip Opening Displacement (DCTOD) as governing parameters for material fragmentation

18th APS-SCCM; 24th AIRAPT

Bonora, N.^1,2 ; Ruggiero, A.^1,2 ; Testa, G.^1 ; Iannitti, G.^2 ; Gentile, D.^2

'University of Cassino and Southern Lazio, Cassino

I-03043, Italy^1

TECHDYN Engineering, Rome

I-00199, Italy^2

关键词: Calibration functions;    Circumferential cracks;    D. digital image correlation (DIC);    Dynamic fracture toughness;    Experimental procedure;    Fracture parameter;    Fragmentation theory;    Governing parameters;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/11/112009/pdf
DOI  :  10.1088/1742-6596/500/11/112009

来源: IOP

【 摘 要 】

Fragmentation in metals can be approached either by Mott statistical or by Energy-based fragmentation theory. Recently, Grady showed that the two theories can be reconciled showing that the material parameter that drives tendency to fragmentation and fragment size is the dynamic fracture toughness. Experimental data do not completely agree with these conclusions. In this paper, the dynamic crack tip opening displacement (CTOD) is proposed as fracture parameter which can account for plastic deformation occurring prior fracture. Here, an experimental procedure for determining the critical dynamic CTOD is presented. The circumferential crack bar tension (CCB(T)) was investigated for its use with tensile Hopkinson bar testing equipment. The calibration function in the dynamic range was determined via finite element analysis (FEA). The critical dynamic CTOD was measured using both high speed video recording, with digital image correlation (DIC) technique, and clip gauge at the crack mouth. The proposed procedure has been used to investigate dynamic fracture resistance of high purity copper (99.98%) and to correlate it with available fragmentation data.