Scholarlink

<p>This study investigates Mode II (in-plane shear) crack propagation and stress intensity factor (SIF) evaluation in AL7075-T6 aluminum alloy, a material extensively employed in aerospace and structural applications. The role of SIF in fracture mechanics is established as a critical parameter for assessing crack initiation and growth under shear-dominated loading. Finite Element Modelling (FEM) in ANSYS 2025R1, supported by mesh refinement and accurate boundary conditions, was employed to determine SIF values, which were subsequently validated using a Modified Nodal Displacement Extrapolation Method (NDEM) an enhanced formulation that incorporates quarter-point singular elements and a three-point extrapolation scheme to improve crack-tip stress singularity capture, distinguishing it from the conventional two-point standard approach. All analyses conform to ASTM E647 standards. Compact Shear (CS) specimens, derived from Richard's geometry, were adopted for fatigue crack growth experiments. Results revealed that increasing crack length corresponds to higher SIF values, reaching the fracture toughness of 25&#xa0;MPa√m at 69&#xa0;mm crack length. Comparative analysis showed close agreement between FEM (24.56368&#xa0;MPa√m) and NDEM (24.6658&#xa0;MPa√m). Fatigue life prediction through the Paris–Erdogan relation indicated failure at approximately 132,121 cycles. Crack retardation mechanisms including residual compressive stresses, plasticity-induced closure, and strain hardening were identified. The findings provide insights for fatigue life assessment, fracture toughness behavior, and design reliability of shear-loaded aerospace components.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Evaluation of In-plane shear mode crack propagation and fatigue crack growth in aluminum alloys using modified nodal displacement extrapolations

  • 期刊论文

  • 发表日期：

    2026年5月25日

查看全文
  • L. J. Kirthan,
  • Santhosh Doreswamy,
  • V. L. Jagannatha Guptha,
  • Rakesh Biradhar,
  • Mahantesh M. Math,
  • Shrishail B. Sollapur

摘要

This study investigates Mode II (in-plane shear) crack propagation and stress intensity factor (SIF) evaluation in AL7075-T6 aluminum alloy, a material extensively employed in aerospace and structural applications. The role of SIF in fracture mechanics is established as a critical parameter for assessing crack initiation and growth under shear-dominated loading. Finite Element Modelling (FEM) in ANSYS 2025R1, supported by mesh refinement and accurate boundary conditions, was employed to determine SIF values, which were subsequently validated using a Modified Nodal Displacement Extrapolation Method (NDEM) an enhanced formulation that incorporates quarter-point singular elements and a three-point extrapolation scheme to improve crack-tip stress singularity capture, distinguishing it from the conventional two-point standard approach. All analyses conform to ASTM E647 standards. Compact Shear (CS) specimens, derived from Richard's geometry, were adopted for fatigue crack growth experiments. Results revealed that increasing crack length corresponds to higher SIF values, reaching the fracture toughness of 25 MPa√m at 69 mm crack length. Comparative analysis showed close agreement between FEM (24.56368 MPa√m) and NDEM (24.6658 MPa√m). Fatigue life prediction through the Paris–Erdogan relation indicated failure at approximately 132,121 cycles. Crack retardation mechanisms including residual compressive stresses, plasticity-induced closure, and strain hardening were identified. The findings provide insights for fatigue life assessment, fracture toughness behavior, and design reliability of shear-loaded aerospace components.

Graphical Abstract