Classification of thermal induced strain cycles and study of associated fatigue damage in integral bridge steel H-piles


DİCLELİ M., Karalar M.

10th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2020, Sapporo, Japan, 11 - 15 April 2021, pp.3971-3978 identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1201/9780429279119-544
  • City: Sapporo
  • Country: Japan
  • Page Numbers: pp.3971-3978
  • Middle East Technical University Affiliated: Yes

Abstract

© 2021 Taylor & Francis Group, LondonSeveral cycle counting methods exist in the literature for the study of fatigue damage generated in structures. Level Crossing, Peak, Simple range and Rainflow counting methods are those using the stress and deformation range to count the number of cycles. Close examination of the existing field measurement data for integral bridges revealed that the measured cyclic strains in steel H-piles consists of large amplitude, primary small amplitude and secondary small amplitude cycles. However, the above mentioned cycle counting methods do not take into consideration the primary and secondary small amplitude strain cycles. Because of the fact that these small strain cycles are part of the low-cycle fatigue effects on steel H piles, a new cycle counting method is developed. The developed cycle counting method is then used to estimate the number of large amplitude strain cycles per year due to seasonal temperature changes and the number and relative amplitude (relative to the amplitude of large amplitude strain cycles) of primary small amplitude strain cycles and secondary small amplitude strain cycles per year due to daily or weekly temperature changes. Then, using the available experimental data, an equation is developed to estimate the fatigue life of integral bridge steel H-piles as a function of the number and amplitude of large, primary small and secondary small amplitude strain cycles. It is observed that small amplitude thermal-induced strain cycles have only a negligible effect on the fatigue life of steel H-piles at the abutments of integral bridges. This is also verified experimentally.