Application method of forming limit strain diagram under nonlinear strain path

Abstract

The invention discloses an application method of a forming limit strain diagram under a non-linear strain path. The application method comprises the following steps: step 1, determining basic parameters of a sample material, and constructing a non-linear forming limit diagram; 2, carrying out finite element Dynaform simulation calculation to output primary and secondary strain data tables; 3, thedata processing program classifies the data into one-way stretching-two-way stretching, two-way stretching-two-way stretching and other strain paths, and a data file is output; and step 4, predictingthe forming performance of the part by two nonlinear forming curves and linear forming limit curves in the nonlinear forming limit diagram and corresponding classification paths, finding out a nonlinear path characteristic rupture unit, and modifying the mathematical model to determine an actual machining process scheme. According to the method, strain data output by a simulation model is classified into uniaxial tension-biaxial tension, biaxial tension-biaxial tension and other paths according to nonlinear strain path features, and model feature regions are accurately evaluated in one-to-onecorrespondence with constructed nonlinear forming limit diagrams.

Description

technical field [0001] The invention relates to the field of sheet metal stamping and forming processing, in particular to the application method of the forming limit strain diagram under the nonlinear strain path, which is mainly used for predicting and judging the rupture of local complex feature parts in the forming of sheet metal, and accurately evaluating the forming process of the workshop part model performance. Background technique [0002] The stamping process is widely used in the manufacturing field due to its high production efficiency, high precision, stable quality and low cost. The stamping material is generally a thin metal plate with a thickness of less than 2mm. After several deformations such as deep drawing, bending and bulging or several combined deformations in the mold, the parts with the required shape and performance are obtained. At the same time, in the lightweight process of aerospace and automobile manufacturing, various high-strength steel plat...

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Problems solved by technology

The finite element calculation process is complicated and the amount of output data is large, and it is difficult to intuitively judge the position of the nonlinear strain path history...

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