Development of Stress Concentration Factor (K_TG) Chart for Finite Length of Bar with Longitudinal Varying Circular Hole Position in Uniaxial Tension

Abstract

Existing chart of gross stress concentration factor (Ktg) has been adequate but the ever-increasing complexity in the design of steel structures is challenging its continued deployment in eccentric applications. This research develops new chart of Ktg for eccentricity ratio e/c of 3 for several longitudinal hole positions in a finite length of flat bar in tension. Employing finite element analysis (FEA), analytical and experimental methods, the study investigates 60 design points. Test vehicles (TVs) are steel plates measuring 200 mm long, 40 mm wide (b), and 4 mm thick. ANSYS mechanical package is used to simulate the response of computer-aided-design models of the TVs to an applied uniaxial tensile load of 5.0 kN. Implementation of the developed Ktg chart in computation of maximum stress in a flat plate with hole produces stress results which are circa 98.97% identical with that generated from FEA simulation. Specifically, at critical hole position of 0.15b measured from load point at bar end, developed chart application demonstrates improvements of circa 55.6 and 65.0% from stress values computed using existing charts of Ktg and nominal stress concentration factor for centre hole in plate (Ktn), respectively. Developed ktg chart adoption will deliver highly reliable steel product designs.</p