Fatigue Strength of Band Saws

Abstract

One of the major disadvantages of band saws is their low durability. Breakages during the operation are mostly caused by fractures in notches between the blades of the band as a result of the fatigue phenomenon. The strength of the band saw blades is ensured if the assurance coefficient value is greater than the theoretically determined one. The value of the assurance coefficient of 2 is recommended. A schematic limit-amplitude diagram was used to calculate the durability of band saws. A formula for the estimation of the assurance coefficient was derived. It was used for the calculation of the assurance coefficients of the band saw blades manufactured in accordance with GOST 6532–77, which are applicable in dividing band saw machines. The resulting value of the assurance coefficient was 1.44. The value is extremely low for the band saws because it is much lower than required. Band saw blades should be sharpened regularly to ensure a long and reliable service life. It should be made not only to ensure the required sharpness of the blades but also to remove the defective layers in notches caused by fatigue phenomena. In the article, there are more recommendations for improving the durability of the blades of the band saws. The durability of a new type of band saw with curved aerostatic guides and hard alloy blades was evaluated. Its assurance coefficient was 2.4. Therefore, the machine can be operated reliably for a long time without regular treatment of the notches. Consequently, band saws have low durability due to their increased breakdown rate and low wear resistance. Hence, the costs of their purchase and treatment rise. Therefore, the results presented in the article are practically applicable. For citation: Prokofiev G.F., Kovalenko O.L. Fatigue Strength of Band Saws. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 136–145. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-136-145