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Discussion: “J integral analysis of stable crack growth,” by I.-H. Lin, J. P. Hirth, and A. R. Rosenfield

✍ Scribed by S. J. Burns

Publisher
Springer Netherlands
Year
1980
Tongue
English
Weight
130 KB
Volume
16
Category
Article
ISSN
1573-2673

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✦ Synopsis

A method for deducing the J crack driving force value versus crack extension curve, the J_ curve, during stable crack growth has recently R been reformulated by L1n, et al. This new proposed relation for J is intended to apply to rectangular bend beams with a through thickness crack subject to bending only.

It is shown here that in general, the proposed, reformulated J relationship applies only to a very restricted class of test specimens -constant J specimens.

Linear elastic, deeply notched and unstable, non-linear elastic bend beams are not constant J test specimens. The proposed reformulated J relationships which involve measurable bending moments, conjugate angular rotations, and crack extensions will not apply to bend beams since in these test pieces both J and the bending moment may not, in general, be held constant simultaneously while the crack extends.

From (i) it follows that b 1 3 F 3F ~ M , B ?b 3(9 c @ c = j a n d 1 3&_J Oc _ ~J b B 3b 30 c

(3)

📜 SIMILAR VOLUMES

Corrections: Discussion: “J Integral Ana
Corrections: Discussion: “J Integral Analysis of Stable Crack Growth,” by I.-H. Lin, J. P. Hirth, and A. R. Rosenfield
✍ S. J. Burns 📂 Article 📅 1981 🏛 Springer Netherlands 🌐 English ⚖ 165 KB

A method for deducing the J crack driving force value versus crack extension curve, the JR curve, during stable crack growth has recently been reformulated by Lin, et al. This new proposed relation for J is intended to apply to rectangular bend beams with a through thickness crack subject to bending

J integral analysis of stable crack grow
J integral analysis of stable crack growth
✍ I.-H. Lin; J. P. Hirth; A. R. Rosenfield 📂 Article 📅 1980 🏛 Springer Netherlands 🌐 English ⚖ 151 KB

Rice, et al. [I] have also stated that the moment/angle relation is of the form\* \*Several authors [2-5] have used an alternative approach of explicitly including plastic flow in the analysis of JR" For example, Rice and coworkers [3-5] use a criterion for stable crack growth of a constant crack

Response: Discussion of “J integral anal
Response: Discussion of “J integral analysis of stable crack growth,” by S. J. Burns [1]
✍ I.-H Lin; J. P. Hirth; A. R. Rosenfield 📂 Article 📅 1980 🏛 Springer Netherlands 🌐 English ⚖ 201 KB

Burns [i] has asserted that, in general, the formulation of J that we proposed recently [2] only applies to a very restricted class of test specimens, mainly including constant J specimens. He suggests that in the general case J is a state function [3] of two variables among: displacement angle @ as

Crack opening displacement and the rate
Crack opening displacement and the rate of fatigue crack growth
✍ R. J. Donahue; H. Mc I. Clark; P. Atanmo; R. Kumble; A. J. McEvily 📂 Article 📅 1972 🏛 Springer Netherlands 🌐 English ⚖ 739 KB

Using a direct proportionality between the rate of fatigue crack growth and crack opening displacement above a threshold, it is shown that fatigue crack growth data for a wide variety of different materials can be accurately described in terms of the mechanical properties and two material constants