| With the development of gas industry,large-scale iron and steel enterprises, thedemand of large-scale gas storage in China is also increasing. As a kind of gas storagestructure, the gas tank is widely used in metallurgical and chemical industries. Due tothe special industrial steel structure, its design not only needs to meet therequirements of structural strength, but also to match the safety standard through acontrolling of structure deformation. This gas tank has high soft and low dampingcharacteristics and its main vibration frequency is close to high winds for thestructure is designed into thin outer wall and large size cylinder structure, and theheight and diameter often reach to about100m. Thus it is sensitive to wind load andthe wind-induced dynamic response is larger. On account of the increased sensitivityof structure to wind, the estimation and control of wind-induced responses havebecome more important during the design of wind loads. In order to guarantee thesecurity and economy efficiency of such a large gas tank structure, as well a s toprovide reference for our specification revision, wind load response characteristicsare studied by the means of in-situ test of a large gas tank in this article.On the premise of the test result of high altitude wind velocity and windprototype, this dissertation analyzed the characteristic of the measured large-scale gastank wind field. Synchronously according to the measured pressure data, the windpressure of gas tank surface is also analyzed. Meanwhile, in order to verify thereliability of the wind tunnel test results, the author compares and analyzes thecharacteristics of wind pressure of gas tank surface and the results and standards ofwind tunnel tests.With the methods of peak picking, mobile station and power spectrum functionanalysis, the modal parameter identification is carried out to test the gas tank inspiredby wind load under the natural environment, which results to modal parameters thatgas tank piston is in1/8~5/8high five conditions. By analyzing the functionnumerically, it is found that with the piston rising, its frequency basically isdecreasing.Through establishing two kinds of gas tank finite element model, and comparingthem with the measured dynamic characteristics, the dissertation gets thecorresponding modal parameters. The thesis also puts forward the method of comparison between finite element model and the measured model and discovers thata more ideal model—gas tank without cover is close to the measured model.According to the results from measured prototype of the acceleration response ofthe gas tank, the characteristic of the acceleration response is analyzed. By using thewind pressure time interval obtained from the wind tunnel test to act on the modelwithout cover, using the linear finite element method (fem) to work out the responseof the gas tank in time domain, the author compares these data with the results of theacceleration response of the gas tank and concludes that the two results are close toeach other and the results from finite element modal can contain the measured resultsof the acceleration response of the gas tank. |
