Abstract: By applying finite element method simulation technology,static structural,modal and harmonic response module,the dynamic numerical simulations of the server chassis structure under prestress state were carried out.The dynamic analysis contain modal analysis and harmonic response analysis.The inherent frequency and vibration modes of the server chassis,harmonic response regularity caused by fan vibration and the comparison between prestressed and non-prestressed modal analysis can be concluded.According to the results,the second order modal vibration mode which inherent frequency is near 90Hz is primarily located on the back of the chassis,easily causing damage to the mainboard.The difference between prestressed and non-prestressed modal analysis is small.The maximum amplitude of the harmonic response vibration caused by the fan vibration source is near 90 Hz,located on the back of the chassis base.This study proposes a dynamic analysis method about the server chassis and provides theoretical reference for the optimization design of the chassis structure.

Key words: server chassis, modal analysis, harmonic response, numerical simulation, dynamic analysis