Abstract: The present disclosure provides a method for air bending a plate of material such as steel which is characterised by having two bending steps, wherein the bending punch in the second bending step has a smaller radius and/or the die width used in the second bending step is smaller than the die width used in the first bending step. The method of the disclosure can achieve a significant improvement in the bendability of materials, particularly high strength steels. The disclosure also provides new bending apparatus that are specifically adapted to carrying out the method of the disclosure, including a nested double die having a second narrower die residing below and within the first die, and an adjustable die having a height adjustment means (either in the support, bending punch or both) capable of accommodating movement of the material during the adjustment to form the second die width.

Abstract: Method for characterizing a material (10), characterized in that it comprises the steps of carrying out a bending test and calculating a cross-section moment, M of said material (10) using the following equation: M = F · L m ? ( ? 1 ) 2 · cos 2 ? ( ? 1 ) where F is the applied bending force, Lm (?1) is the moment arm, and ?1 is the bending angle. The expression for the moment, M, fulfils the condition for energy equilibrium: ?Fds=?2Md?2 when the true bending angle, ?2 is: ? 1 - ? t · sin ? ( ? 1 ) L m ? d ? ? ? 1 .

Abstract: The present disclosure provides a method for air bending a plate of material such as steel which is characterised by having two bending steps, wherein the bending punch in the second bending step has a smaller radius and/or the die width used in the second bending step is smaller than the die width used in the first bending step. The method of the disclosure can achieve a significant improvement in the bendability of materials, particularly high strength steels. The disclosure also provides new bending apparatus that are specifically adapted to carrying out the method of the disclosure, including a nested double die having a second narrower die residing below and within the first die, and an adjustable die having a height adjustment means (either in the support, bending punch or both) capable of accommodating movement of the material during the adjustment to form the second die width.

Abstract: Method for characterizing a material (10), characterized in that it comprises the steps of carrying out a bending test and calculating a cross-section moment, M of said material (10) using the following equation: M = F · L m ? ( ? 1 ) 2 · cos 2 ? ( ? 1 ) where F is the applied bending force, Lm (?1) is the moment arm, and ?1 is the bending angle. The expression for the moment, M, fulfils the condition for energy equilibrium: ?Fds=f2Md?2 when the true bending angle, ?2 is: ? 1 - ? t · sin ? ( ? 1 ) L m ? d ? ? ? 1 .

Abstract: The device comprises a stamping member (2) arranged to be conveyed towards and hit a material body (1) with such a velocity that a rebound motion of the stamping member (2) is generated while a permanent deformation of the material body (1) is generated. The device has structure (3) for counteracting the rebound and generating at least one additional impact of the stamping member (2) against the material body (1) within a period, during which kinetic energy in the material body (1) generates an additional deformation in the body.