Large plasticity induced crack initiation from U-notches in thin aluminum sheets under mixed mode loadin

Abstract

Ductile failure is investigated experimentally and theoretically in U-notched Al 7075-T6 thin sheets under mixed mode I/II loading. First, several U-notched rectangular sheets are subjected to mixed mode I/II failure tests and the load-carrying capacity of the sheets are experimentally recorded. Then, the Equivalent Material Concept (EMC) is employed in conjunction with the U-notch maximum tangential stress (UMTS) and U-notch mean stress (UMS) criteria to theoretically estimate the load-carrying capacity of the U-notched Al 7075-T6 sheets. It is shown that the experimental failure loads are well predicted by means of both the UMTS-EMC and UMS-EMC criteria. Moreover, the experimental observations and the elastic-plastic finite element analyses indicate that the U-notched aluminum sheets fail by the large-scale yielding (LSY) regime.

Tensile failure prediction of U-notched plates under moderate-scale and large-scale yielding regimes

“…aluminum alloys in aerial vehicles etc. Recently, some research works have been performed on ductile failure of notches under various loading conditions [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…To check whether EMC is capable of being combined with brittle fracture criteria in the context of the linear-elastic notch fracture mechanics (LENFM) for predicting failure in engineering components made of ductile materials other than the steel materials reported in Refs. [6,10], some new ductile failure analyses have been recently carried out by Torabi and co-researchers [11][12][13][14][15][16][17] on notched aluminum plates under different in-plane loading conditions. They have published seven papers on this subject; three on pure mode I loading [11,13,15] and four on mixed mode I/II loading [12,14,16,17].…”

“…It can be seen in Refs. [11][12][13][14][15][16][17] that EMC has been linked to the two well-known stress-based brittle fracture criteria, namely the maximum tangential stress (MTS) and mean stress (MS) criteria, making it possible to wave the considerable plastic region at the notch neighborhood and predict well the LCCs of the U-and V-notched Al 7075-T6 and Al 6061-T6 plates using the linear-elastic analyses. It has been reported in Refs.…”

“…It has been reported in Refs. [11][12][13][14][15][16][17] [11,16,17] without performing elastic-plastic analyses. Very good agreements have been found to exist between the theoretical results of the EMC-ASED criterion and the experimental results.…”

Using XFEM Techniques to Predict the Damage of aluminum 2024T3 notched under tensile load

“…They demonstrated that a linear elastic analysis allows to summarize all the high phases of the given cycle of fatigue resistance using a single SED value. Torabi's other works with Mohammad Hosseini [12] have experimentally and theoretically studied U-slotted Al 7075-T6 plates under the mixed loading mode (I / II). The concept of equivalent material (EMC) is used in conjunction with the criterion of maximum tangential stress (UMTS) and mean stress UMS.…”