PSI - Issue 28

G.N. Gusev et al. / Procedia Structural Integrity 28 (2020) 2328–2334 Author name / Structural Integrity Procedia 00 (2019) 000–000

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At most points, the stress level did not exceed the value corresponding to the normal operation of the structure specified in the normative documents and obtained through mathematical simulations.  Hence, it can be concluded that the behavior of the tank wall predominantly follows an elastic scenario, not going to plasticity. Analyzing the results of the experiment, namely, its technical side, a number of features of the operation of strain sensors in severe environment should be noted. The most severe environment for proper operation of the sensor is to achieve complete adhesion with the body of the object of measurement. The problem is that all adhesives degrade under the influence of moisture and temperature differences. Cyanoacrylate glue is applicable only in short-term experiments. It is very important to protect the sensor from moisture ingress, otherwise, the glue will degrade and disrupt the sensor. It is also important to perform thermal compensation of the measured deformations in the manner shown. This method is most correct because it does not distort the measured strain values. Another problem that has been identified during the experiment is the rate of strain measurement for shape stability loss tasks. The object changes its geometry in fractions of a second. The change in the deformed state occurs very quickly. Even the strain sign has changed. For a qualitative description of this phenomenon, it is necessary to be able to record a signal from sensors at a speed of not more than 0.00001 s. Also, according to the results of the experiment, it can be recommended to use accelerometers to record a vibration portrait of the structure to describe the state of the object. The evolution of the vibration portrait (Patrikeev and Salatov, 2013) is directly related to the deformed state. 5. Conclusions Analysis of the results of the study has indicated that the available normative documents referred to mathematical modeling of the stress-strain state of buildings and structures cover, with sufficient accuracy, all possible states of the model objects. The exact causes of certain defects are often unknown and, therefore, the elucidation of mechanisms responsible for defect formation requires a large amount of calculations. In this work, we have developed and tested an algorithm for estimating and measuring the condition of a structure, which allows one to save time and money needed to accurately determine the stress-strain state of the model objects. The need for such techniques is indisputable because more and more technological devices, e.g. sensors and data communications equipment, appear on the market every day. It is very important to use high-quality technical solutions to record the deformed state of full-scale objects. The sensors shall meet the environmental conditions and the rate of change of the state of the object. It is important to test untested solutions on primitive and well-controlled primitive objects under appropriate conditions. Testing will identify and correct shortcomings. References A.Yu. Prokopov, K.E. Tkacheva. A study of stress-strain state of vertical vessel subject to dynamic operating loads // Engineering Bulletin of Don, №3 (2015) Mansurova S.M., Tlyasheva R.R., Ivakin A.V., Shaizakov G.A., Bairamgulov A.S Cylindrical steel tank stress - strain state evaluation with operational loads taken into account // Oil and Gas Engineering: electronic journal, 2014. № 1. Tarasenko A.A., Chepur P.V., Gruchenkova A.A. Analysis of the technical condition of tanks with inadmissible geometrical imperfections in the wall shape // Oil economy – 2017, №6, P118-121. Salnikov A.P. Evaluation of stress - strain state of the tank according to the results of scanning - // Thesis for Candidate of Technical Sciences, Moscow, 2016. Dobromyslov A.N. Assessment of buildings and structures by external features. M. Publishers. ASV. 2004, P.72. Khoroshilova G.A., Khoroshilov V.S. Strain monitoring of engineering objects as part of geodesic monitoring // INTEREXPOGEO-SIBIR -2012 –V.1., No 1. P. 77-80. Patrikeev A.V., Salatov E.K. Fundamentals of the method of dynamic monitoring of deformation characteristics of buildings and structures // Bulletin of MSBU - 2013. – No 1. –P. 133–138.