Calculation of flank fracture acc. to FVA 556/III

For the evaluation of the flank fracture load capacity according to FVA 556/III, this calculation method considers the efforts in the center section of the virtual cylindrical gears according to FVA 411. The support points for the calculation of the stress curves in the material depth depend on the Hertzian contact flattening at the respective calculation point on the line of action of the virtual cylindrical gears. At eleven evenly distributed calculation points on the line of action of the virtual cylindrical gears, the stress curve is determined by means of 110 support points in the material depth.

The scope of the calculation method is limited as follows:

• Hertzian pressure: 500 N/mm² ≤ p_H,local ≤ 3000 N/mm²
• Local equivalent curvature radius: 5 mm ≤ ρ_red,lok ≤ 150 mm
• Case hardening depth: 0.3 mm ≤ CHD₅₅₀ ≤ 4.5 mm

If the mentioned quantities are outside the validity range, the calculation procedure is aborted. A statement about the risk of flank fracture is permissible from a material depth of at least half the Hertzian flattening width. The Hertzian flattening width is output.

Quelle:

• Bojadiev, I., Tobie, T.; Stahl, K.: Nachrechnung Flankenbruch Kegelräder. FVA-Forschungsvorhaben 556/III, FVA-Heft 1100, Forschungsvereingigung Antriebstechnik e. V., Frankfurt, 2014.
• Pellkofer, J.; Drechsel, A.; Hein, M.; Stahl, K.: Erweiterung KNplus, FVA-Forschungsvorhaben 49/XIII, FVA-Heft 1342, Forschungsvereingigung Antriebstechnik e. V., Frankfurt, 2019.