Physical experiment and numerical simulation combined method for predicting metal extrusion forming cracking

Abstract

The invention discloses a physical experiment and numerical simulation combined method for predicting metal extrusion forming cracking. The method comprises the steps that first, a hot-stretch test isperformed on metal, and then a Normalized Cockcroft&Latham damage model is selected for calculation to obtain a critical damage value of the metal; second, simulated verification is performed on thecritical damage value of the metal; and third, the critical damage value of the metal after simulated verification is embedded into a metal extrusion finite element model, and the cracking phenomenonin the metal extrusion forming process is predicted. According to the method, a physical experiment and simulated verification are combined to acquire the reliable critical damage value of the metal,then the positions and shapes of metal surface and internal cracks generated in multiple extrusion forming processes are predicted through numerical simulation of the extrusion processes, an error caused by a test mistake is avoided, prediction precision is improved, the prediction range is expanded, therefore, crack generation is avoided, and the quality of metal extrusion pieces is improved.

Description

technical field [0001] The invention belongs to the technical field of metal extrusion cracking prediction technology, and in particular relates to a method for predicting metal extrusion cracking by combining physical experiments and numerical simulations. Background technique [0002] In the metal forming process, due to the complex temperature field conditions and stress conditions, crack defects are prone to occur, resulting in the scrapping of the entire component and bringing huge losses to production. In the process of metal plastic forming, the damage inside the metal is a cumulative process. As the amount of deformation increases, the damage value is also increasing, and when it reaches a critical value, cracks appear inside the metal. Therefore, it is very necessary to predict the occurrence of cracks during metal plastic forming in advance, to manufacture qualified components by optimizing the process, and to ensure the safety and reliability of components in the...

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Problems solved by technology

[0005] After searching the existing literature, no public reports have been found to obtain critical damage values ​​from physical experiments for numerical verification.

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