Method for optimum design of tee shape

Abstract

The invention discloses a design method of shape optimization of a tee, which is carried out according to the following steps: first, a finite element analysis model and a corresponding mathematical expression of static structural analysis are built, then the displacement vector, strain vector and stress vector of a node are calculated; the total correction value and the component at the normal direction at the node are calculated; according to the determined total correction value and the component at the normal direction at the node, the node coordinate is corrected; the structure after correction is carried out stress calculation and test. The design method of shape optimization corrects the existing tee structure design, bases on finite element model, moves a high stress node along the direction of the outer normal on the structure surface by proportion, moves a low stress node along the opposite direction of the outer normal on the structure surface by proportion, and finally obtains a tee structure with a more suitable geometric shape and effective reduction of structure stress concentration.

Description

technical field [0001] The invention belongs to the field of mechanical design, and relates to a mechanical structure shape optimization design, in particular to a tee shape optimization design method. Background technique [0002] As a common structure of pressure vessels and pressure piping systems, tees are widely used in thermal power plants, nuclear reactors and petrochemical industries. [0003] The book "Stress Analysis and Strength Design of Pressure Vessels" discloses on pages 140 to 141 that the tee designed according to the existing tee structure design specifications has a relatively high stress concentration at the corner of the intersecting line in the main pipe and the branch pipe. As a result, the tee becomes an easily damaged component in the pipeline. [0004] The article "Discussion on Cracks in the Tee-way for Cooling the Main Steam Pipeline" stated that the cost of the tee-way structure itself is not high, but the economic loss caused by the abnormal sh...

AI Technical Summary

Problems solved by technology

The reason for this defect is, on the one hand, it is compatible with the early manual design tools; on the other hand, the shape of the reinforcement is not completely designed according to the strength of the tee structure, that is, the parts that need more reinforcement are not fully reinforced , the parts that do not need to be strengthened get too much reinforcement, resulting in limited reinforcement effect

[0007] The patent "A Method for Optimal Design of the Shape of a Tee" (Patent No. ZL 02139433.4, Authorized Announcement No. CN1217124, Authorized Announcement Date 2005.8.31) discloses an optimal design method for the shape of a tee based on node displacement, effectively reducing the The stress level of the tee is determined, but the shape of the end surface of the main pipe and the branch pipe of the tee designed by this method is not circular, and cannot be directly connected to the pipe, and must pass through a transition pipe before it can be connected to the pipe system

However, the tee does not need to take over during normal use, so this method has certain limitations

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