Characterization of Metal Foil in Anisotropic Fracture Behavior with Dynamic Tests

The fitness-for-service codes require the characterization of non-aligned multiple flaws for flaw evaluation, which is performed using a flaw proximity rule. Worldwide, almost all such codes provide their own proximity rule, often with unclear technical bases of the application of proximity rule to ductile or fully plastic fracture. In particular, the effect of flaw dimensions of multiple surface flaws on fully plastic fracture of non-aligned multiple flaws had not been clear. To clarify the effect of the difference of part through-wall and through-wall flaws on the behavior of fully plastic fracture, the fracture tests of flat plate specimens with non-aligned multiple part through-wall flaws were conducted. When the flaw depth a was shallow with 0.4 in ratio of a to thickness t, the maximum load Pmax occurred at penetration of multiple flaws and the effect of vertical distance of non-aligned multiple flaws H on Pmax was not so significant. However, when flaw depth was deep with 0.8 in a/t, Pmax occurred after penetration of flaws and the effect of H on Pmax could be seen clearly. It was judged that the through-wall flaw tests were appropriate for discussion of the effect of H on Pmax and the alignment rule of multiple flaws. In addition, in order to clarify the appropriate length parameter to estimate Pmax of test specimens with dissimilar non-aligned through-wall multiple flaws, the fracture tests of plate specimens were also conducted. The effect of different flaw length on Pmax was discussed with maximum, minimum and averages of dissimilar non-aligned multiple flaw lengths. Experimental results showed that the maximum length lmax would be an appropriate length parameter to estimate Pmax, when the non-aligned multiple through-wall flaws were dissimilar.

Download Full-text

Characterization of the Fracture Behavior of Fine-Grained High-Strength Low-Alloy (HSLA) Steels and Iron-Base Alloys Under Low-Temperature and Mechanical Environments

Fractography and Materials Science ◽

10.1520/stp33442s ◽

2009 ◽

pp. 394-394-19

Author(s):

MR Krishnadev ◽

LR Cutler ◽

GJ Sojka ◽

P Gauvin ◽

G Hamel

Keyword(s):

Low Temperature ◽

Fracture Behavior ◽

High Strength ◽

Iron Base ◽

Fine Grained ◽

Hsla Steels

Download Full-text

An experimental study for the characterization of elastic brittle-fracture behavior of materials by means of continuous damage mechanics-aided approaches

Procedia Structural Integrity ◽

10.1016/j.prostr.2018.09.038 ◽

2018 ◽

Vol 10 ◽

pp. 272-279

Author(s):

V.N. Kytopoulos ◽

J. Venetis ◽

A. Altzoumailis ◽

E. Sideridis

Keyword(s):

Experimental Study ◽

Brittle Fracture ◽

Fracture Behavior ◽

Damage Mechanics

Download Full-text

Mechanical and Fractographical Characterization of Extruded Al-Mg-Si-Zr Alloys

MATEC Web of Conferences ◽

10.1051/matecconf/201818802017 ◽

2018 ◽

Vol 188 ◽

pp. 02017

Author(s):

Fulya Kahrıman ◽

Muzaffer Zeren

Keyword(s):

Fracture Behavior ◽

Direct Chill ◽

Grain Structure ◽

Tensile Fracture ◽

Casting Method ◽

Cross Sectional ◽

Fracture Surfaces ◽

The Matrix ◽

Zr Alloys

In this study, the chemical composition of Al-0.8Mg-0.8Si alloys was modified with the addition of 0.1 and 0.2 wt.-% Zr. The billets were manufactured by direct chill casting method, homogenized at 560 °C for 6h and then extruded in order to obtain profiles having hollow and circular sections. Recrystallization layer (shell) became narrower due to the addition of Zr. This was attributed to the formation of very fine precipitates (Al3Zr) within the matrix. The mechanical properties showed that both yield and tensile strengths increased as a function of Zr content. Tensile fracture surfaces were examined by scanning electron microscope and the fractographs reflected the effect of grain structure on the fracture behavior of studied alloys. All fracture surfaces indicated typical dimple ruptures, however, the size of dimples were observed as finer structures as a function of Zr content. As seen in cross-sectional graphs, as the Zr content increased the grain structure was refined due to Al3Zr precipitates. These fine precipitates caused the formation of fine and shallow dimples under loading.

Download Full-text