Thermal shock resistance analysis of cracked nanoplate with embedded elliptical defect via nonlocal differential elasticity theory

Abstract

Elliptical cracks widely exist in practical engineering structures. The nonlocal theory postulates that the stress at a given point depends on the strain at that point itself, as well as the strain fields over the entire computational domain, thereby providing more accurate predictions when materials are scaled down to micro- and nanometers. The novelty of this work lies in the first investigation of nonlocal thermal fracture behavior and thermal shock resistance of nanoplates containing embedded elliptical cracks, for which closed-form analytical expressions of the nonlocal thermal stress field are derived via a semi-analytical approach. Based on the resulting thermal stress fields, the thermal stress intensity factor is calculated, and its variations with crack geometry (particularly the c/a ratio), thermal shock duration, and crack length are systematically analyzed. Furthermore, two failure criteria (the strength criterion and the fracture toughness criterion) are jointly adopted to assess the overall thermal shock resistance, enabling a comprehensive evaluation that complements each criterion’s limitations. Finally, the thermal shock resistance predicted by the nonlocal and local models is compared, revealing the significant scale effect on fracture behavior at the nanoscale.