THE ACOUSTIC RADIATION CHARACTERISTICS OF FUNCTIONALLY GRADED CYLINDRICAL SEHLLS IN THERMAL ENVIRONMENT

Based on the classical shell theory,the forced vibration equations of functionally graded cylindrical shells in the thermal environment with fluid are deduced.The influences of different temperature distribution patterns,shell material parameters and surrounding fluid field parameters on sound radiation induced by functionally graded cylindrical shells are studied.The results show that the temperature variation will change the shell material properties,and generate the thermal stress in the shell,which will impact the characteristics of sound radiation from the shell in the fluid field.The influence of temperature variation is different on the sound power in different frequencies.In the heavy fluid,the impact of temperature variation to the sound power is enhanced with the rising of frequency.In the light fluid,the peak value of sound power is decreased and moved to the low-frequency with the rising of temperature when the frequency is lower,and the sound power near the loop frequency is reduced as well.The influence of uniform temperature rise on sound radiation characteristics is more obvious than that of no-uniform temperature rise.With the no-uniform temperature rise,the impact of volume fraction exponent to sound power in the heavy fluid is more apparent than that in the light fluid,and is embodied in the peak position primarily.