Formulas: 9-2-3-5-2

MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures

Last Updated 29 Oct 2026

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Formula 1

i=2,...,n-1 [9.2.3.5.2(a)] from the measured crack-growth data as illustrated in Figure 9.2.3.5.2. However, alternative methods, such as polynomial fitting of the "a" versus "N" curve, are acceptable for computation of da/dN values. By this indexing and calculating procedure "n" measurements provide "n-2" slope or rate values at all but first and last measurement points. The directly associated stress-intensity factor, K, for each slope computation is computed in accordance with Equation 9.2.3.5.2(b) where g(a,w) is a geometric scaling function dependent on crack and specimen geometry, and S is nominal stress.

MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures

Last Updated 29 Oct 2026

Hover any section to copy its link or text, ask Copilot about it, or bookmark it.

i=2,...,n-1 [9.2.3.5.2(a)] from the measured crack-growth data as illustrated in Figure 9.2.3.5.2. However, alternative methods, such as polynomial fitting of the "a" versus "N" curve, are acceptable for computation of da/dN values. By this indexing and calculating procedure "n" measurements provide "n-2" slope or rate values at all but first and last measurement points. The directly associated stress-intensity factor, K, for each slope computation is computed in accordance with Equation 9.2.3.5.2(b) where g(a,w) is a geometric scaling function dependent on crack and specimen geometry, and S is nominal stress.