بهبود شاخص شناسایی آسیب در صفحات برپایه‌ی اطلاعات شکل مودی با در نظر گرفتن ممان پیچشی

ﺻﻔﺤﺎت از ﻣﻬﻢﺗﺮﯾﻦ اﻟﻤﺎنﻫﺎی ﺳﺎزهای ﻫﺴﺘﻨﺪ ﮐﻪ ﺧﺮاﺑﯽ در آنﻫﺎ ﻣﯽﺗﻮاﻧﺪ ﺑﺼﻮرت ﭘﯿﺶروﻧﺪه ﺑﻪ ﺳﺎﯾﺮ اﻟﻤﺎنﻫﺎ ﻣﻨﺘﻘﻞ ﺷﺪه و ﺳﺒﺐ ﺧﺮاﺑﯽ ﮐﻠﯽ ﺷﻮد. ﻟﺬا ﺷﻨﺎﺳﺎﯾﯽ آﺳﯿﺐ در اﯾﻦ اﺟﺰا، در ﮐﻨﺘﺮل ﺳﻼﻣﺖ ﺳﺎزه ﻧﻘﺶ ﻣﻮﺛﺮی دارد. ﺳﯿﺴﺘﻢ ﻫﺎی ﺷﻨﺎﺳﺎﯾﯽ و ﻣﮑﺎﻧﯿﺎﺑﯽ ﺧﺮاﺑﯽ ﻣﯽﺗﻮاﻧﻨﺪ ﻧﻘﺶ ﺑﺴﯿﺎر ﻣﻬﻤﯽ را در اﯾﻤﻦﺳﺎزی و ﺑﻬﺴﺎزی ﺳﺎزهﻫﺎ و ﺟﻠﻮﮔﯿﺮی از ﺑﻮﺟﻮد آﻣﺪن ﺧﺴﺎرات ﻣﺎﻟﯽ و ﺟﺎﻧﯽ ﻧﺎﺷﯽ از ﻓﺮورﯾﺨﺘﻦ ﺳﺎزهﻫﺎ اﯾﻔﺎ ﻧﻤﺎﯾﻨﺪ و ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻃﻮل ﻋﻤﺮ ﺳﺎزه ﺷﻮد. در اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ ﮐﻤﮏ ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ دادهﻫﺎی ﺷﮑﻞ ﻣﺪی و ﻣﺸﺘﻘﺎت آنﻫﺎ و ﺑﺎ ﺗﻮﺳﻌﻪی ﮐﺪﻫﺎی ﻋﺪدی اﻟﻤﺎن ﻣﺤﺪود و ﻣﺤﺎﺳﺒﻪی ﺷﯿﺐ و اﻧﺤﻨﺎی ﺻﻔﺤﻪ ﺑﺮ اﺳﺎس روش ﺗﻔﺎﺿﻞ ﻣﺤﺪود ﻣﺮﮐﺰی، ﺗﺎﺛﯿﺮ ﭘﯿﭽﺶ ﻋﻼوه ﺑﺮ ﺧﻤﺶ ﺑﺮ روی اﻟﻤﺎن ﺻﻔﺤﻪای در ﻓﺮآﯾﻨﺪ ﺷﻨﺎﺳﺎﯾﯽ آﺳﯿﺐ در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﺑﺎ ﻫﺪف ارزﯾﺎﺑﯽ اﺻﻼح ﻓﺮﻣﻮﻟﺒﻨﺪی در ﻋﻤﻠﮑﺮد ﺷﺎﺧﺺ-ﻫﺎی ﻣﻮﺟﻮد، ﻣﻘﺎﯾﺴﻪای در زﻣﯿﻨﻪی ﺷﻨﺎﺳﺎﯾﯽ آﺳﯿﺐ در ﺻﻔﺤﺎت ﺑﺎ اﺳﺘﻔﺎده از ﺳﻨﺎرﯾﻮﻫﺎی ﻣﺨﺘﻠﻒ ﺧﺮاﺑﯽﻫﺎی ﻣﻨﻔﺮد و ﭼﻨﺪﮔﺎﻧﻪ ﺑﺎ ﺧﺼﻮﺻﯿﺎت ﻣﺘﻔﺎوت ﺻﻮرت ﭘﺬﯾﺮﻓﺘﻪ اﺳﺖ و ﺷﺎﺧﺺ ﺑﻬﺒﻮد ﯾﺎﻓﺘﻪای ﻣﻌﺮﻓﯽ ﮔﺮدﯾﺪه. ﻣﻘﺎﯾﺴﻪی ﻧﺘﺎﯾﺞ در دوﺣﺎﻟﺖ ﺳﺎﻟﻢ و آﺳﯿﺐدﯾﺪه ی ﺳﺎزه، ﻧﺸﺎن دﻫﻨﺪه ی اﻓﺰاﯾﺶ ﻗﺪرت و دﻗﺖ ﺷﻨﺎﺳﺎﯾﯽ ﻣﮑﺎن آﺳﯿﺐﻫﺎی ﻣﻨﻔﺮد و ﭼﻨﺪﮔﺎﻣﻪ ﺑﻪ وﯾﮋه در ﻟﺒﻪﻫﺎی ﺻﻔﺤﻪ ﺑﻮده و اﻋﺘﺒﺎر ﺳﻨﺠﯽ ﻋﻤﻠﮑﺮد ﺷﺎﺧﺺ ﺑﻬﺒﻮد ﯾﺎﻓﺘﻪ ﺑﺎ دادهﻫﺎی ﺗﺠﺮﺑﯽ، ﻧﺸﺎندﻫﻨﺪه ی دﻗﺖ ﻣﻨﺎﺳﺐ اﯾﻦ ﺷﺎﺧﺺ اﺳﺖ.

Improving the damage identification indicator for plate-like structures by considering twisting moment based on mode shape data

Plates are one of the most important structural elements in which failure can be progressively transferred to other elements and cause overall damage. Therefore, identification of damage in these components plays an important role in the control of structural health. Damage detection and locating systems have a critical role in retrofitting and improving of structures and preventing the financial and human damages caused by the collapse of structures and would increase theirs service life .The main purpose of this thesis is to study how to identify and evaluate damage in platelike structures using nondestructive methods, and improving this operation process.. In this study, the effect of torsion in addition to bending on the plate element is considered in the damage identification process by analyzing the shape data and their derivatives and by developing finite element numerical codes, calculating the slope and curvature of the plate based on the central finite difference method, Efficiency and performance of this method has been studies by different scenarios of damage in plate with different characteristics and an improved index has been introduced. Comparison of the results in both healthy and damaged structures showed increased robustness and accuracy of identifying the location of individual and multistep injuries, especially at the edges of the plate and also Improved indicator performance validation with experimental data indicates appropriate accuracy of this index.