تحلیل ضربه سرعت پایین بر ورق‌های‌‌ حلقوی تقویت شده با نانولوله‌های کربنی به‌صورت هدفمند

در اﻳﻦ ﭘﮋوﻫﺶ، ﺗﺤﻠﻴﻞ ﻋﺪدی ﺿﺮﺑﻪ ﺳﺮﻋﺖ ﭘﺎﻳﻴﻦ ﺑﺮ ورقﻫﺎی ﺣﻠﻘﻮی ﺗﻘﻮﻳﺖ ﺷﺪه ﺑﺎ ﻧﺎﻧﻮﻟﻮﻟﻪﻫﺎی ﻛﺮﺑﻨﻲ ﺑﻪﺻﻮرت ﻫﺪﻓﻤﻨﺪ ﺑﺎ اﺳﺘﻔﺎده از روشﻫﺎی اﻟﻤﺎن ﻣﺤﺪود اراﺋﻪ ﺷﺪه اﺳﺖ. ﻣﻌﺎدﻻت ﺗﻌﺎدل ورق ﺑﺮ اﺳﺎس ﺗﺌﻮری ﺗﻐﻴﻴﺮ ﺷﻜﻞ ﺑﺮﺷﻲ ﻣﺮﺗﺒﻪ اول ورق و اﺻﻞ ﻫﻤﻴﻠﺘﻮن اﺳﺘﺨﺮاج ﺷﺪه اﺳﺖ و ﺑﺮای ﺣﻞ اﻳﻦ ﻣﻌﺎدﻻت از روش اﻟﻤﺎن ﻣﺤﺪود و اﻟﮕﻮرﻳﺘﻢ ﭘﻴﻜﺎرد اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﺑﺮای ﺷﺒﻴﻪﺳﺎزی ﻧﻴﺮوی ﺗﻤﺎس ﺑﻴﻦ ورق و ﺿﺮﺑﻪزﻧﻨﺪه از ﻗﺎﻧﻮن ﺗﻤﺎس ﻫﺮﺗﺰ اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﻧﺘﺎﻳﺞ ﺑﺪﺳﺖ آﻣﺪه ﻧﺸﺎن ﻣﻲدﻫﻨﺪ، ﻛﻪ ﺗﻮزﻳﻊ ﻧﺎﻧﻮﻟﻮﻟﻪﻫﺎ ﺑﻪ ﺗﺮﺗﻴﺐ ﺑﻪ ﺷﻜﻞ ud ،fgv ، fg-x و fg-o در راﺳﺘﺎی ﺿﺨﺎﻣﺖ، دارای ﺑﻴﺸﺘﺮﻳﻦ ﻧﻴﺮوی ﺗﻤﺎﺳﻲ ﻣﻲ ﺑﺎﺷﻨﺪ. ﻫﻤﭽﻨﻴﻦ ﻧﺘﺎﻳﺞ ﻋﺪدی اﻳﻦ ﻣﻄﺎﻟﻌﻪ ﻧﺸﺎنﮔﺮ اﻳﻦ اﺳﺖ، ﻛﻪ اﻓﺰاﻳﺶ ﻛﺴﺮ ﺣﺠﻤﻲ ﻧﺎﻧﻮﻟﻮﻟﻪﻫﺎی ﻛﺮﺑﻨﻲ از 0/11 ﺑﻪ 0/17، ﺳﺒﺐ اﻓﺰاﻳﺶ 32 درﺻﺪی ﻧﻴﺮوی ﺗﻤﺎﺳﻲ ﻣﻲﮔﺮدد، در ﺣﺎﻟﻲ ﻛﻪ زﻣﺎن ﺗﻤﺎس را ﻛﺎﻫﺶ ﻣﻲدﻫﺪ.

Low velocity impact analysis of FGCNT annular plate

In this study, low velocity impact analysis of functionally graded carbon nanotube annular plate based of finite element method is presented for the first time. The governing equations are based on first shear deformation theory and Hamilton’s principle. To model the contact force between annular plate and impactor, modified contact Hertz law has been used. Results of present study is compared with previous studies, and it shows good agreement. The effect of different parameters such as distribution and volume fraction of carbon nanotubes, and also, different mass and velocity of impactor on contact force and transverse displacemet of plate have been investigated. Results denotes that by increasing the volume fraction of carbon nanotube from 11 to 17 %, the contact force 32% is increased and the contact time is notably decreased. Also, results show that, the FGX distribution of nanotubes along the thickness of plate, has the highest contact force and the lowest contact time.