Method of establishing sheet metal high-speed forming limit diagram

Abstract

The present invention relates to a method of establishing a sheet metal high-speed forming limit diagram. The method comprises the steps of: using sheet metal high-speed experimental devices; first using a lighter punch to obtain forming limit points under high strain rate and different strain paths; using a heavier punch to obtain forming limit points under medium strain rate and different strain paths; on the basis of a ordinary forming test machine, adjusting to an appropriate collection frequency of an acquisition system, and adjusting the speed of the punch to obtain forming limit points under quasi-static or low strain rate and different strain paths; and connecting the high-speed forming limit points under all strain rates and strain paths into a curve surface by using a fitting method in a piece of Matlab software, and defining a three-dimensional forming limit surface. The height of the forming limit surface can determine the formability of the sheet metal under different strain rates, and higher forming limit surface indicates better forming performance of the sheet metal under the strain rate.

Description

technical field [0001] The invention relates to the field of high-speed forming of sheet metal, in particular to a method for establishing a limit diagram for high-speed forming of sheet metal. Background technique [0002] High-speed high-energy forming includes a variety of technological methods, mainly including explosive forming, electromagnetic forming, and electro-hydraulic forming, that is, the high energy stored in electricity, chemistry, and machinery is released instantaneously for processing. Both electromagnetic forming and explosive forming can reach a processing speed of 15-300 m / s, which can greatly improve processing efficiency. At the same time, under the high strain rate of many metal materials, the forming limit is greatly improved compared with the low-speed process at room temperature. Explosive forming, electromagnetic forming, and electrohydraulic forming have been studied abroad as early as the middle of the last century, and now they have entered th...

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Problems solved by technology

[0007] The problem to be solved by the present invention is to provide a method for establishing the high-speed forming limit diagram of sheet metal, which can not only solve the forming performance evaluation problem that can be solved by the traditional forming limit diagram, but also provide a method that can accurately and conveniently evaluate the high-speed forming process of sheet metal Fracture problem in

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