|Table of Contents|

Study on ductile multiple-crack extension by microvoid coalescence mechanism(PDF)

《火箭推进》[ISSN:1672-9374/CN:CN 61-1436/V]

Issue:
2019年03期
Page:
33-40
Research Field:
研究与设计
Publishing date:

Info

Title:
Study on ductile multiple-crack extension by microvoid coalescence mechanism
Author(s):
JIANG Wei1;  XU Xuejun1;  LI Yazhi2
(1.Science and Technology on Liquid Rocket Engines Laboratory, Xi'an 710100;2.School of Aeronautics,Northwestern Polytechnical University, Xi'an 710072)
Keywords:
ductile multiple-crack;  cell;  void coalescence;  plastic limit-load
PACS:
V41; TB31
DOI:
-
Abstract:
For the pre-cracked specimen under tensile loading, due to the high stress triaxiality ratio near the crack tip, microvoid dilation and subsequent coalescence by reduction of the inter-void ligament dominates the failure mechanism.Void coalescence criteria should be established properly to simulate the crack extension based on the void damage mechanism.Firstly, the results of 3D cell computation were used to establish a macroscopic equivalent strain criterion for 2524-T3 aluminum alloy.Thereafter, a new form of the plastic limit-load criterion only depending on macroscopic strain is derived with the assumption that voids keep the spherical expansion until coalescence.Finally, these two void coalescence criteria are combined with Gurson-Tvergaard-Needleman(GTN)model to form GTN-E and GTN-L models, respectively.The ductile multiple-crack extension process in 2524-T3 aluminum alloy sheet was simulated.Comparison vith the test results shows that the predictions of the fracture behaviors, including crack extension, coalescence and final fracture, have a good agreement with the experiment data, which also validates the current approach.

References:

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Last Update: 2019-06-30