3D Nonlinear Finite Element Analysis Of Radial Steel Gate

Since the establishment of China, a lot of radial steel gates were applied to hydraulicand hydro-power engineering. After a long period of operation, security incidents occurredin some of the early gates using plane system design method because of deviation on thestress state of plane system and space system. In the recent30years, finite element methodbecame mature gradually and was applied to3D analysis of radial steel gate. However,research works of static were generally restricted to linear analysis of deformation andstress of radial steel gate, and most of them didn’t consider stiffener at the back of thepanel in the modeling phase. In the meantime, they didn’t check static stability of radialsteel gate in the analysis phase. In addition, the corrosion problem of the gate isincreasingly prominent with the long-term use of the gates, domestic research on localcorrosion of radial steel gate panel is still very limited. Therefore, in this paper the studiesare carried out in the following aspects.Using nonlinear finite element method, static stability of radial steel gate without armweb member under the design water head was analyzed, and the results of space stabilitycalculation formulas in the code were compared. In the meantime, the influence of staticstability that caused by truss form and section size of the supporting arm were researched.Then, the nonlinear analysis were carried out for with and without the stiffeners on thepanel of the steel gate, and the stress and displacement results of the two models werecompared, on this basis, the local corrosion of the panel of radial steel gate with stiffenercomponent was simulated, moreover, the corrosion sensitive region of the radial steel gateand the change rules of the largest gate stress along with the corrosion depth wereresearched.The analysis results show that buckling failure of the supporting arm without webmember under hydrostatic pressure happened, therefore, research works of static can’t berestricted to linear analysis of deformation and stress of radial steel gate, nonlinear stabilityof radial steel gate should be checked. Checking the stability of the supporting arm withoutweb member by using space stability calculation formula in the code for design of steelstructures concludes that the supporting arms don’t appear the buckling phenomenon，however，the result calculated by the ANSYS software is that the arms have happenedbending-torsional buckling, which shows that the stability calculation formula in the codecannot fully consider geometric nonlinearity and space force conditions of the supportingarms, for safety’s sake, it is necessary to use the finite element method in the structural checking of radial steel gate.Setting web member in the supporting arm truss plane orreducing the beam web height while increasing the flange width of the supporting arm canimprove the spatial buckling stress and avoid the buckling failure of radial steel gateeffectively. Because of the stiffeners on the panel, the panel stress ranges from180MPawhich can not meet the requirement of strength to150MPa which can meet therequirements, this illustrates that the stiffener on the panel is an important component inensuring the safety of the gate structure security and can’t be ignored when establishing3Dmodel of radial steel gate. The study finds that the part of the larger equivalent stress whengate does not appear corrosion is the corrosion sensitive part of radial steel gate. If this partappears corrosion, the maximum stress value of gate will linearly increase with increasingcorrosion depth, and when corrosion depth reaches a certain degree, this part of the panelmay enter the plastic state. So superintendents should test on this part firstly. In order toavoid the strength damage, corrosion part should be timely maintenance.