Unified creep constraint parameter solutions for surface cracks in plates under tensile and bending loads

Abstract

In order to accurately assess creep crack initiation (CCI) and growth (CCG) life for elevated temperature cracked structures, both out‐of‐plane and in‐plane constraints need to be considered, and the unified creep constraint parameter solutions should be investigated. In this work, the new unified creep constraint parameter Ac values for plate structures with various surface crack sizes subjected to tensile and bending loads have been investigated and obtained using three‐dimensional (3D) finite element (FE) analysis. The effects of material creep properties, crack sizes, loading modes, and plate thickness on the parameter Ac have also been analyzed. The estimation equation of Ac for materials with different creep exponent n has been fitted. The parameter Ac solutions can be used in CCI and CCG life evaluation of the C*‐Ac two‐parameter approach for cracked plates subjected to tensile and bending loads.

Impact of out‐of‐plane constraint on creep crack growth behavior of M174+ aluminum alloys by nano‐computed tomography (CT)

“…[3][4][5][6][7][8] Actually, these two cases present an extreme value of out-of-plane constraint. 9,10 To measure the standard fracture toughness of deep crack compact tension specimens, the thickness (B) of specimens is processed to be half of the width (W). 11,12 These conditions of specimens enable the crack tip to be in plane strain state, resulting in a conservative evaluation value of material toughness.…”