نوع مقاله : گرایش دینامیک، ارتعاشات و کنترل
نویسندگان
1 گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه بوعلی سینا ، همدان، ایران
2 گروه مهندسی مکانیک. دانشگاه بوعلی سینا. همدان. ایران
3 گروه مهندسی مکانیک. دانشگاه پیام نور.تهران. ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Considering the importance of the effect of temperature reduction in many industrial structures, especially aerospace industries, in this article, the experimental and numerical analysis of the effect of cold on the natural frequencies of a cylindrical shell has been discussed. After the construction of a cylindrical steel shell, first it was excited by non-contact method and using the acoustic test room and by sending acoustic waves, and its natural frequencies were measured by frequency analysis of the sound pressure level at environmental temperature. Also, to validate the test method, the results were compared with the results obtained by the modal hammer contact method and the finite element simulation results in COMSOL software and it was shown a good adaptation between them. Next, the shell was transferred to the cold thermal chamber to reach a temperature of less than minus 70 degrees Celsius, and the test was repeated in the acoustic room and the effect of temperature drop on the values of the natural frequencies of the structure were studied by both experimental and numerical methods. The results show that as the temperature decreases, the natural frequencies of the structure increase. It can also be seen from the results of the numerical solution that the sensitivity of each of the natural frequencies of the structure is not the same to temperature changes. For example, the highest sensitivity to temperature is related to the fifth and seventh modes and the lowest sensitivity is related to the eighth and sixth modes.
کلیدواژه‌ها [English]
)