Explanation:

The given statement is false. The Stress Concentration Factor (SCF) is not the ratio of nominal stress obtained by elementary equations for the minimum cross-section and the highest value of actual stress near the discontinuity.

What is Stress Concentration Factor (SCF)?

When a structural component has a discontinuity or a stress raiser, such as a hole, crack, or fillet, the stress distribution in the vicinity of the discontinuity becomes non-uniform. This non-uniform stress distribution results in a localized increase in stress, known as stress concentration. The Stress Concentration Factor (SCF) is a dimensionless factor that quantifies the increase in stress due to stress concentration.

Definition of SCF:

The Stress Concentration Factor (K) is defined as the ratio of the highest stress (actual stress) at the discontinuity to the nominal stress (uniform stress) that would exist in the absence of the discontinuity.

Mathematically,
Stress Concentration Factor (K) = Actual Stress / Nominal Stress

Explanation of the Given Statement:

The given statement incorrectly states that the Stress Concentration Factor (SCF) is the ratio of the nominal stress obtained by elementary equations for the minimum cross-section to the highest value of the actual stress near the discontinuity.

The nominal stress is the stress that would exist in the absence of the discontinuity and is calculated using elementary equations for the minimum cross-section. It does not take into account the localized increase in stress caused by stress concentration.

The actual stress, on the other hand, takes into account the localized increase in stress near the discontinuity. It is the highest stress value at the discontinuity.

Therefore, the correct definition of the Stress Concentration Factor (SCF) is the ratio of the highest stress (actual stress) at the discontinuity to the nominal stress (uniform stress) that would exist in the absence of the discontinuity. The given statement is false.