What is a formation diagram?

The formation limit diagram (FLD), also known as Keeler-Goodwin diagram, is a graph that illustrates the behavior of sheet metal below different levels of voltage. The line describing the behavior of the metal is called the Formation limit curve (FLC). The formation limit diagram provides information about the maximum voltage that the metal can undergo before breaking or neck. The diagrams are designed using the tester strips of sheet metal and the deformation measurement.

Formation schemes are a graph in a two -dimensional coordinate system, with the main strain to bring on the Y -axis and a smaller trunk deduced on the X axis. The trunk is the degree of deformation - the main voltage is defined as in the direction of higher deformation, while the lower voltage is in the direction with less deformation. Each has different types and different sheet thicknesses.

FLC is an irregular parabolic curve, with a minimum occurs on or near the main axis of the voltage. Materials subjected to strains that lie above the curve fail, while the trunks under the curve are safe for metal application. Fld areUsually the graphs of two curves - the area between the curves is a critical deformation zone or safety zones where the material can be safe or burst, so in practice it is best not to apply these tribes. The critical deformation, which is likely to occur in this zone, is called the neck, which is when the metal is stretched in some areas.

The formation scheme is developed using a number of tests. During the tests, the voltage is applied to the metal strips of different widths. Different stripe widths simulate different voltage conditions. Each stripe is marked with a pattern of a circular grid that is used to measure voltage.

The trunk is usually applied to the strips by means of a hemispheric strike. And the metal belt is stretched until the neck is observed. The voltage values ​​for the main and small axes can be obtained by measuring the circular grid previously marked on the strip.

Computer methods can also be used to measure voltage. Images taken by computer during the deformation process can be compared to a reference grid comparable to the KruHot grid for metal. The computer can calculate the trunks using these images. Another method compares before and after the pictures of the circular grid to calculate the trunk.