Pre-fatigue damage on the mechanical properties of Q690D steel

Abstract

This article aims to analyze the influence of high cycle fatigue damage on the mechanical properties and low cycle fatigue performance of Q690D. Monotonic tensile and cyclic loading tests were performed on Q690D specimens with different degrees of high cycle fatigue damage. Degradation models were established to describe the declining trending of mechanical properties with the increase of pre-fatigue damage. Manson-Coffin models for Q690D steels of different pre-damage levels were established. Besides, a comparison was presented between Q690D and Q355B. The research work in this article provides a fundamental reference for the appropriate assessment of the mechanical performance of Q690D high-strength steel structures after long-term alternating loading.

Investigation on seismic performance degradation of hub large‐span roof structures considering corrosion and damage accumulation

“…The roof structures of these transportation hubs primarily take the form of trusses, grid structures, and reticulated shells, making them susceptible to fatigue damage induced by wind vibration. Additionally, the hub large‐span roof structures endure prolonged vibrations from high‐speed train loads, leading to a significant reduction in their bearing capacity and seismic performance over time 3,4 . Moreover, the hub large‐span roof structures, located in a coastal area, are exposed to a corrosive environment, resulting in defects such as corrosion holes, corrosion pits, and corrosion layers on the surface of the components, which leads to the reduction of the bearing capacity and energy dissipation performance of the structure 5–7 …”