# STRESS CONCENTRATION FACTORS FOR TWO EQUAL CIRCULAR HOLES IN AN INFINITE PLATE

Theoretical stress concentration factors (Kt) of two equal circular holes in infinite plate can be calculated by this calculator for tension loads. In addition to stress concentration factor calculation, the calculator can be used to find maximum stress values at the edge of the hole if loading parameters are known. See footnotes of the "Results" table for the necessary equations for the stress calculations.

There exist some validity conditions for the equations which are used in the calculations. If input parameters don't satisfy validity conditions of equations, a warning message is given by the calculator.

The formulas and parameters used in the calculator are given in " List of Equations " section of this page.

##### Calculator:

 INPUT PARAMETERS Parameter Symbol Value Unit Hole diameter d mm cm m inch ft Distance between hole centers L Plate thickness t In-plane normal stress σ MPa psi ksi
###### Note: Use dot "." as decimal separator.

 RESULTS LOADING TYPE - IN-PLANE NORMAL STRESSES Parameter Symbol Value Unit UNIAXIAL TENSION PARALLEL TO ROW OF HOLES (σ1=σ ,σ2=0) Stress concentration factor * Kt --- --- Maximum tension stress σ --- MPa psi ksi UNIAXIAL TENSION NORMAL TO ROW OF HOLES (σ1=0 ,σ2=σ) Stress concentration factor for point-B* KtB --- --- Nominal tension stress σnom --- MPa psi ksi Maximum tension stress at point-B σB --- BIAXIAL STRESS ( σ2 = σ1) Stress concentration factor for point-B* KtB --- --- Nominal tension stress σnom --- MPa psi ksi Maximum tension stress at point-B σB ---

##### Definitions:

Stress Concentration Factor: Dimensional changes and discontinuities of a member in a loaded structure causes variations of stress and high stresses concentrate near these dimensional changes. This situation of high stresses near dimensional changes and discontinuities of a member (holes, sharp corners, cracks etc.) is called stress concentration. The ratio of peak stress near stress riser to average stress over the member is called stress concentration factor.

Kt: Theoretical stress concentration factor in elastic range = (σmaxnom)

##### List of Equations:

 Tension

##### Reference:
• Pilkey, W. D..(2005). Formulas for Stress, Strain, and Structural Matrices .2nd Edition John Wiley & Sons