This work presents the development of two different finite piping elbow elements with two nodal tubular sections formechanical analysis. The formulation is based on thin shell displacement theory, where the displacement is based onhigh-order polynomial or trigonometric functions for rigid-beam displacement, and uses Fourier series to model warpingand ovalization phenomena of cross-tubular section. To model the internal pressure effect an additional formulation is usedin the elementary stiffness matrix definition. Elbows attached to nozzle or straight pipes produce a stiffening effect due to the restraintof ovalization provided by the adjacent components. When submitted to any efforts, the excessive oval shape may reduce thestructural resistance and can lead to structural collapse. For design tubular systems it is also important to consider the internal-pressureeffect, given its effect on the reduction of the pipe flexibility. Some conclusions and examples are compared with results produced by other authors.
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