Experimental investigation of slosh parametric instability in liquid filled vessel under seismic excitations

• Slosh response under vertical seismic excitations in rectangular vessels is investigated.
• Governing equation for parametric instability is derived and discussed.
• Shake table test is performed to obtain realistic slosh behavior in rectangular liquid filled vessel of aspect ratio 0.5.
• Stability chart is plotted analytically and experimentally.
• Experimental stability chart illustrates that there is no risk of parametric instability for PGA below 0.2 g.

Present investigation aims to analyze parametric instability at free surface of liquid in rectangular vessel under seismic excitations close to primary resonance mode. Analytical solution is discussed and stability chart is plotted to highlight different regions of stability and instability. The analysis is based on solving the Mathieu equations derived from incompressible and inviscid fluid. Shake table tests are performed to evaluate the instability behavior under vertical seismic loads. The shake table tests are carried out in a vessel of aspect ratio h/L = 0.5. Comparison of test results with analytical solution is presented. The analytical solutions are obtained without considering damping effect leading to more conservative results compared to the experimental results.