Stress Analysis And Structure Research For The Flat Plates With Openings And Rectangular Vessels

Flat plates are the common member of the pressure vessels. Although some regulations about the intensity for it have been specified in GB 150-1998 Steel Pressure Vessels and ASME Boiler and Pressure Vessel Code, further research on the flat plates with openings should be carried out, and no formula for designing the rectangular vessels available. Stress analysis and structure research for the flat plates with openings and the rectangular vessels were executed in this paper and corresponding results are as follows.(1) According to the finite element analysis for the solid flat plates with different connections of shell, stress ratio showed the results by FEA were accordance with analytic results. Then the stress distributing in the plates were analyzed.(2) The flat plates with round openings and rectangular openings were taken into consideration. The additional reinforcing elements were used within the width twice over the diameter of openings for the round flat plates with small openings. While reinforcing in the required area, the results were accordance with the stress value of solid plates. But if the method of increasing the thickness of plates uniformly which was provided GB150 was adopted, there was also large stress intensity, which could not meet the purpose of reinforcement.For the round plates with large openings, the results by FEA presented that there was large stress in the connecting region of the flat plates to cylindrical shell. The model with conical or round angle transition could be effective to reduce the stress, but the connecting region still appeared large primary stress and secondary stress, the results by FEA should be restricted by thrice allowable stress. There was small stress value in the connecting region if the slope of the conical transition was 1:3.The results of the plates with rectangular openings showed that the method of equivalent inscribed circle could satisfy the stress requiring for the principle part of plates. The round transition which was added in the comer of rectangular could effectively reduce the value of peak stress.(3)Using inscribed circle for the rectangular vessels, the rectangular plates were equivalent to round plates, and a simple formula for the side plates of rectangular vessels were given as well. The results of two methods were coincidence.(4) Refer to the stress test for the round plates with rectangular openings and the rectangular vessels, the tested data was accordance with the results by FEA.