Research On Surface Deterioration Diseases And Weathering Degree Evaluation Of Stone Cultural Relics Based On Infrared Thermal Imaging

Stone cultural relics are important carriers of Chinese long history and culture.Due to the relatively stable physical and mechanical properties of rocks,the number of stone cultural relics that have been passed down for a long time is large.At present,the use of Infrared thermal imaging to detect the surface degradation diseases of stone cultural relics mainly focuses on single diseases such as fissure,water seepage,empty drums,and there is a lack of detection research on the overall weathering degree of stone cultural relics and the deterioration of multiple diseases affect each other and deteriorate.Therefore,this paper takes limestone stone relics as an example to carry out the research on heat conduction regularity and weathering degree classification of surface deterioration diseases of stone cultural relics based on Infrared thermal imaging.This paper selects the most distributed limestone stone cultural relics in Hangzhou as the research object,first introduces the detection principle,influencing factors of Infrared thermal imaging technology,common disease types and their deterioration rules,then analyzes the feasibility of using infrared thermal imager to detect the surface deterioration diseases of stone cultural relics.Secondly,the limestone of the same material around the cultural relics was collected,and the ultrasonic velocity,water absorption rate,porosity and hardness were carried out on the limestone test blocks with different weathering degrees.The Infrared thermal imager was used to record the similarities and differences of temperature changes at surface fractures and empty drums under different weathering degrees and moisture content of limestone.Then,the conduction difference of heat in different diseases and the stress damage caused by the temperature difference thermal stress are analyzed by numerical simulation,and the accuracy of the indoor test is further verified.Finally,the ultrasonic speed,water absorption rate,porosity and hardness of Bai Fo rock statues in Wushan Scenic area,Hangzhou,quantifying the specific weathering degree of each test area,combined with the existing specifications,record the temperature variation after water spray cooling,and fitting the detection results of the Infrared thermal imager with the results of the conventional detection means.It is found that the fitting degree of the variation of surface T_v and the weathering degree of rock is high.The feasibility of evaluating the weathering degree of stone surface relics by temperature variation T_v is verified.Based on the detection results of the field Infrared thermal imaging,the classification of the surface weathering degree of Stone cultural relics based on Infrared thermal imaging is studied,and obtained the following conclusions:(1)In the process of limestone aging,there are disease areas,and the deterioration speed is faster and more serious than the fresh and intact areas.(2)The surface layer porosity,water content,fissure depth,empty drums volume and ambient temperature when detected by Infrared thermal imaging can significantly affect the temperature variation T_v after heating or cooling.(3)The thermal conduction process and heat distribution law of different diseases on the limestone surface are quite different in the numerical simulation,and the stress failure of the thermal stress caused by the temperature difference is highly consistent with the test results.(4)Infrared thermal imager on the stone cultural relics field detection results consistent with indoor test,numerical simulation rule,and the results and other conventional detection means results fit is higher,shows that the Infrared thermal imager detect the accuracy of the stone surface weathering degree,based on this,a method for evaluating the weathering degree of surface of stone cultural relics based on Infrared thermal imaging was established with temperature variation T_v as the evaluation index.