A Hybrid Experimental-Numerical Benchmark for Stress Concentration at a Circular Hole: Rigor, Validation, and Uncertainty in Photoelastic Analysis
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Abstract
This study establishes a high-fidelity experimental benchmark for the canonical problem of stress concentration at a circular hole in a finite-width aluminum plate. By applying a formal Photoelastic Experimental Hybrid Method (PEHM) framework, we integrate quantitative reflection photoelasticity, comprehensive uncertainty quantification, and direct finite element analysis (FEA) validation. A bonded PhotoStress® coating and reflection polariscope were used to measure full-field strains under incremental uniaxial tension (5-25 kN). The mean experimental stress concentration factor (SCF) was determined to be K_t = 2.50, with an expanded uncertainty (95% confidence) of ±0.05. A complementary 3D FEA model predicted a SCF of 2.65, showing a 6% deviation which is critically analyzed in the context of experimental limitations and model assumptions. This work successfully bridges established experimental techniques and modern computational validation needs, demonstrating that rigorous photoelastic methodology can generate reliable quantitative data essential for calibrating models of more complex structural details.