اﺛﺮ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ زﻟﺰﻟﻪ ﺑﺮ ﭘﺎﺳﺦ دﯾﻨﺎﻣﯿﮑﯽ ﻣﺨﺎزن ﺑﺘﻨﯽ ﻣﺴﺘﻄﯿﻠﯽ ﺑﺎ اﺳﺘﻔﺎده از روش ﺗﺮﮐﯿﺒﯽ اﻟﻤﺎن ﻣﺤﺪود و ﻫﯿﺪرودﯾﻨﺎﻣﯿﮏ ذرات ﻫﻤﻮار

Effect of Earthquake Frequency Content on Dynamic Response of Concrete Rectangular Tanks Using Coupled Finite Element Method and Smoothed Particle Hydrodynamics

ﻣﺨﺎزن زﻣﯿﻨﯽ ﺑﺘﻨﯽ، ﮐﺎرﺑﺮد ﮔﺴﺘﺮدهاي در ذﺧﯿﺮه آب، ﻓﺎﺿﻼب، ﻧﻔﺖ، ﻣﻮاد ﺷﯿﻤﯿﺎﯾﯽِ ﺳﻤﯽ و ﺳﺎﯾﺮ ﻣﺎﯾﻌﺎت دارﻧﺪ. ﺑﻨﺎﺑﺮاﯾﻦ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﻮع ﮐﺎرﺑﺮي آﻧﻬﺎ، ﺑﻪ ﻃﻮر ﻣﻌﻤﻮل در رده ﺳﺎزهﻫﺎي ﺑﺎ اﻫﻤﯿﺖ ﺧﯿﻠﯽ زﯾﺎد ﺷﺮﯾﺎنﻫﺎي ﺣﯿﺎﺗﯽ ﻗﺮار دارﻧﺪ؛ در ﻧﺘﯿﺠﻪ ﺗﺤﻠﯿﻞ دﯾﻨﺎﻣﯿﮑﯽ ﻣﺨﺎزن ذﺧﯿﺮه ﻣﺎﯾﻌﺎت از ﻣﻮﺿﻮﻋﺎت ﻣﻬﻢ در ﻣﻬﻨﺪﺳﯽ زﻟﺰﻟﻪ اﺳﺖ. از ﻃﺮﻓﯽ ﺑﺮرﺳﯽ رﻓﺘﺎر ﻟﺮزهاي ﻣﺨﺎزن و اﻧﺪرﮐﻨﺶ ﻣﺎﯾﻊ درون آن اﻫﻤﯿﺖ ﺑﺴﺰاﯾﯽ دارد. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﺤﯿﻂ آب ﺑﻪ روش ﻫﯿﺪرودﯾﻨﺎﻣﯿﮏ ذرات ﻫﻤﻮار و ﺳﺎزه ﻣﺨﺰن ﺑﻪ روش اﺟﺰاي ﻣﺤﺪود ﻣﺪﻟﺴﺎزي ﺷﺪﻧﺪ. روش ﻫﯿﺪرودﯾﻨﺎﻣﯿﮏ ذرات ﻫﻤﻮار ﮐﻪ ﯾﮏ روش ﺑﺪون ﻣﺶ اﺳﺖ داراي ﻣﺰاﯾﺎي ﻓﺮواﻧﯽ ﻧﺴﺒﺖ ﺑﻪ دﯾﮕﺮ روشﻫﺎي ﺳﻨﺘﯽِ ﺑﺮ ﭘﺎﯾﻪ ﺷﺒﮑﻪﺑﻨﺪي ﻣﯽﺑﺎﺷﺪ. ﺑﻪ ﻣﻨﻈﻮر ﺻﺤﺖ ﺳﻨﺠﯽ، درﺳﺘﯽ ﻣﺪلﺳﺎزي ﺑﺎ ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﮕﺎﻫﯽ و ﻋﺪدي ﻣﻮﺟﻮد ﻣﻘﺎﯾﺴﻪ ﺷﺪ، دﻻﯾﻞ و ﭘﺎراﻣﺘﺮﻫﺎي ﻣﻮﺛﺮ در اﻧﺘﺨﺎب رﮐﻮردﻫﺎ ﺑﯿﺎن، و ﺳﭙﺲ ﻣﺨﺰن ﻣﺪﻟﺴﺎزي ﺷﺪه ﺗﺤﺖ ﺗﺎﺛﯿﺮ رﮐﻮرد زﻟﺰﻟﻪﻫﺎي ﺑﺎ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ ﻣﺨﺘﻠﻒ ﺑﻪ ﺻﻮرت ﺗﺎرﯾﺨﭽﻪ زﻣﺎﻧﯽ ﺗﺤﻠﯿﻞ ﮔﺮدﯾﺪ. ﭘﺎراﻣﺘﺮﻫﺎي ارﺗﻔﺎع ﺗﻼﻃﻢ، ﺷﺘﺎب در ﺑﺎﻻي دﯾﻮاره ﻣﺨﺰن، ﺑﺮش ﭘﺎﯾﻪ، ﻧﯿﺮو در ﻋﺮض واﺣﺪ و ﺟﺎﺑﻪﺟﺎﯾﯽ دﯾﻮاره ﺑﺮاي ﻣﻘﺎﯾﺴﻪ ﺑﺪﺳﺖ آورده ﺷﺪﻧﺪ و در اﻧﺘﻬﺎ ﺗﺎﺛﯿﺮ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ ﺗﺎﺛﯿﺮ اﻧﺪرﮐﻨﺶ آب-ﺳﺎزه ﺑﺮ ﻣﺨﺰن ﺑﺮرﺳﯽ ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ رﮐﻮرد ﺑﺎ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ ﮐﻤﺘﺮ ﻣﻨﺠﺮ ﺑﻪ ﺗﻼﻃﻢ ﺑﺎ ارﺗﻔﺎع ﺑﯿﺸﺘﺮ ﻣﯽﺷﻮد؛ در ﺣﺎﻟﯽ ﮐﻪ رﮐﻮرد ﺑﺎ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ ﻣﺘﻮﺳﻂ ﻋﻠﯿﺮﻏﻢ ارﺗﻔﺎع ﺗﻼﻃﻢ ﮐﻤﺘﺮ ﺑﺎﻋﺚ ﺑﻪ وﺟﻮد آﻣﺪن ﭘﺎﺳﺦﻫﺎي ﺑﺰرﮔﺘﺮ ﺳﺎزه ﻣﺨﺰن ﻣﯽﮔﺮدد. ﻫﻤﭽﻨﯿﻦ ﻣﺸﺎﻫﺪه ﺷﺪ ﮐﻪ ﻓﺮﮐﺎﻧﺲﻫﺎي ﻏﺎﻟﺐ ﺗﻼﻃﻢ ﺑﺎ ﮐﺎﻫﺶ ﻣﺤﺘﻮاي ﻓﺮﮐﺎﻧﺴﯽ زﻟﺰﻟﻪ، اﻓﺰاﯾﺶ ﭘﯿﺪا ﻣﯽﮐﻨﺪ.

Concrete ground tanks are widely used in storing water, sewage, oil, toxic chemicals and other liquids. Depending on their type of use, they are usually in the category of very important structures of lifelines; Therefore, the dynamic analysis of liquid storage tanks is one of the most important issues in earthquake engineering. On the other hand, the seismic behavior of the storage tanks and its interaction with liquid is very important. In this study, the water medium is modeled using smoothed particle hydrodynamics method and tank’s structure modeled by finite element method. The smooth particle hydrodynamics, which is a meshfree method, has many advantages over other traditional grid-based methods. For verification purposes, the modeling accuracy was compared with the available experimental and numerical results, the reasons and parameters that were effective on selecting the records were expressed, and then the time history analysis was performed on the modeled storage tank including records with different frequency content. The parameters of sloshing height, acceleration at the top of the tank’s wall, base shear, force per unit width and wall displacement were obtained for comparison. Finally, the effect of frequency content was studied considering the effect of water-structure interaction on the tank. The results showed that a record with low frequency content results higher sloshing height, while a record with moderate frequency content will cause larger responses on the tank’s structure despite of its lower sloshing height. The study also proved that the dominant frequencies of sloshing increases with decreasing frequency content of earthquake.