شبيه سازي و كاهش ارتعاش دكه اي ساندويچي با ميراگرهاي دانه اي در شناورها با استفاده از روش جريان دو فازگاز-جامد

Simulation and vibration reduction of sandwich panels with granular dampers in vessels using multiphase flow theory of gas-particle

در اﯾﻦ ﺗﺤﻘﯿﻖ، ﮐﺎراﯾﯽ ﻣﯿﺮاﮔﺮﻫﺎي داﻧﻪ اي، در ﺑﻬﺒﻮد ﻋﻤﻠﮑﺮد ارﺗﻌﺎﺷﯽ ﺳﺎزه ﮐﺎﻣﭙﻮزﯾﺘﯽ ﻧﺸﯿﻤﻦ ﻣﻮﺗﻮر در ﯾﮏ ﺷﻨﺎور، ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ زﻣﺎن ﺑﺮ ﺑﻮدن ﻓﺮآﯾﻨﺪ ﻣﺤﺎﺳﺒﺎﺗﯽ ﺗﺤﻠﯿﻞ دﯾﻨﺎﻣﯿﮑﯽ اﯾﻦ ﻣﯿﺮاﮔﺮﻫﺎ ﺑﺎ اﺳﺘﻔﺎده از روﻧﺪﻫﺎﯾﯽ ﻣﺎﻧﻨﺪ اﻟﻤﺎن ﻫﺎي ﮔﺴﺴﺘﻪ، ﯾﮏ ﻓﺮآﯾﻨﺪ ﺟﺎﯾﮕﺰﯾﻦ ﺑﻬﯿﻨﻪ ﻣﺒﺘﻨﯽ ﺑﺮ ﺗﺌﻮري ﭼﻨﺪ ﻓﺎزي ﺟﺮﯾﺎن ﺗﻮﺳﻌﻪ داده ﺷﺪه اﺳﺖ. در ﮔﺎم اول، ﻣﺸﺨﺼﺎت ﯾﮏ واﺣﺪ از اﯾﻦ ﻧﻮع ﻣﯿﺮاﮔﺮﻫﺎ اﺳﺘﺨﺮاج و ﻣﻌﺎدﻻت آن ﺑﻪ ﻣﻨﻈﻮر ﺗﺨﻤﯿﻦ ﺿﺮﯾﺐ ﻣﯿﺮاﯾﯽ ﻣﻌﺎدل ﺗﻮﺳﻌﻪ ﯾﺎﻓﺘﻪ اﺳﺖ. ﺑﻪ اﯾﻦ ﻣﻨﻈﻮر، ﺗﺌﻮري ﭼﻨﺪ ﻓﺎزي ﺟﺮﯾﺎن اﺳﺘﻔﺎده ﻣﯽ ﺷﻮد ﮐﻪ در آن، ﺗﺌﻮري ﺟﻨﺒﺸﯽ ﺟﺮﯾﺎن ﻣﺘﺮاﮐﻢ ﺳﯿﺎﻻت و ﺗﺌﻮري ﻣﻮر-ﮐﻮﻟﻤﺐ ﺟﻬﺖ ﻣﺪل ﺳﺎزي ﺑﺮﺧﻮرد و اﺻﻄﮑﺎك ﺑﯿﻦ ذرات درون ﺳﻠﻮل ﺑﻪﮐﺎر ﻣﯽ رود. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ واﺑﺴﺘﮕﯽ ﻏﯿﺮﺧﻄﯽ ﺿﺮاﯾﺐ ﻣﯿﺮاﯾﯽ ﻣﻌﺎدل، ﺑﻪ داﻣﻨﻪ ﺳﺮﻋﺖ، ﯾﮏ ﮐﺪ ﭘﺎﯾﺘﻮن ﺑﻪ ﺻﻮرت ﺣﻠﻘﻪ ﻫﻤﮕﺮا ﮐﻨﻨﺪه در ﻣﺤﯿﻂ ﻧﺮم اﻓﺰار آﺑﺎﮐﻮس ﺟﻬﺖ ﭘﯿﺎده ﺳﺎزي ﻓﺮآﯾﻨﺪ ﺗﺨﻤﯿﻦ ﻣﯿﺮاﯾﯽ ﻣﻌﺎدل ﺧﻄﯽ آن واﺣﺪ، ﻧﻮﺷﺘﻪ ﺷﺪه اﺳﺖ. در ﺑﺨﺶ ﻧﺘﺎﯾﺞ ﭘﺲ از اﻧﺠﺎم ﺻﺤﺖ ﺳﻨﺠﯽ و اﺛﺒﺎت دﻗﺖ و ﺳﺮﻋﺖ ﻣﺤﺎﺳﺒﺎت، ﻧﺸﺎن داده ﺷﺪ داﻣﻨﻪ ﺷﺘﺎب ارﺗﻌﺎﺷﯽ در اﯾﻦ ﻣﺪل، ﮐﺎﻫﺶ ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ داﺷﺘﻪ اﺳﺖ.

In this research, the efficiency of granular dampers in improving the vibration performance of a composite engine seat structure in a vessel has been investigated. Due to the time-consuming computation process of dynamic analysis of these dampers using processes such as discrete elements, an optimal alternative process based on multiphase flow theory has been developed. First, the characteristics of a unit of this type of damper are extracted and its equations are developed to estimate the equivalent damping coefficient. For this purpose, multiphase flow theory is used, in which the kinetic theory of dense fluid flow and the Moore-Columb theory are used to model the collision and friction between particles within the cell. Due to nonlinear dependence, a Python code has been used as a convergent loop in the ABAQUS software environment to implement the damping estimation process. In the result section, after performing validation and proving the accuracy and speed of calculations, it was shown that the amplitude of vibrational acceleration in this model has significantly decreased.