Actual Problems in Machine Building 2018 Vol. 5 No. 3-4

Актуальные проблемы в машиностроении. Том 5. № 3-4. 2018 Технологическое оборудование, оснастка и инструменты ____________________________________________________________________ 99 QUESTIONS OF INVESTIGATIONS OF THE LOW-CYCLE FATIGUE OF UNIVERSAL JOINTS Kukushkin E.V. , Assistant, e-mail: ironjeck@gmail.com Shvaleva N.A. , Student, e-mail: natalyashvaleva@ya.ru Reshetnev Siberian State University of Science and Technology, 31 Krasnoyarsky Rabochy Av., Krasnoyarsk, 660037, Russian Federation Abstract Low-studied questions concerning research of low-cycle fatigue of universal joints are considered. An analysis is made of the recently published experimental results on the behavior of various metallic materials under biaxial low-cycle fatigue. To assess the limiting state of materials in the theory of low-cycle fatigue, the criteria of four groups are used: deformation, force, energy and criteria based on the account of material damage. Deformational and energy criteria have become most widespread in the calculation practice. Developed on their basis, approaches to create an effective modified deformation criterion. According to the results of the analysis, it is necessary: to test cardan joints at different stages of operation (running-in, normal operation, failure); to assess the influence of manufacturing errors on the performance of cardan joints; substantiate the causes of the formation of surface and deep cracks. Keywords universal joints, low cycle fatigue, criteria