Measurement of buckling load for metallic plate columns in severe accident conditions

• Buckling load was experimentally measured in a wide range of temperature up to 1200 °C.
• Two different test methods for measuring buckling failure load were suggested and compared.
• Creep buckling under compressive load was performed to explain results of buckling tests.
• Reduced buckling load was explained by effects of creep buckling, geometrical imperfection, and thermal stress.
• Buckling processes were visualized by a high speed camera.

In severe accidents, a reactor pressure vessel, its components, and piping have to be under extremely high temperature and high pressure conditions, which results in failure modes like rupture by internal pressure, buckling, creep, and their combinations. In this study, buckling (failure) load was experimentally measured for metallic columns under the compressive force from room temperature up to 1200 °C. A stainless steel was chosen to be a test material to measure the buckling load. Two different test methods were employed to explore the effect of thermal history of the material on the buckling load. Particularly, the effect of creep under a compressive load was considered as a reason for the reduced buckling load at high temperatures. Additionally, finite element simulations were also conducted to predict buckling load for both an ideal column and a column with geometrical imperfection as well. Moreover, buckling process was visualized using a high speed camera to understand buckling processes.