Deformation resistance

The deformation resistance or deformation resistance is a measure of the resistance of a workpiece or material to plastic deformation . ${\ displaystyle k_ {W}}$

definition

The deformation resistance

{\ displaystyle k_ {W} = {\ frac {F} {A}}}

is the ratio of the force F required for deformation and the area A required for deformation , so it has the unit of stress . If the deformation resistance k _W is known, the force to be used for plastic deformation can be determined:

{\ displaystyle \ Leftrightarrow F = k_ {W} \ cdot A.}

The deformation resistance is not a pure material property , since it takes into account not only the material property flow stress (influenced by the composition and temperature of the material) but also the properties of the considered forming process (shape of the workpiece and speed of the forming) as a form function : ${\ displaystyle k_ {f}}$ ${\ displaystyle q_ {f} \ geq 1}$

{\ displaystyle k_ {W} = k_ {f} \ cdot q_ {f}.}

The shape function can be interpreted as a kind of inverse efficiency .

application

In the practical application of plastic shaping processes , the deformation resistance is used to calculate the required forming forces. The understanding of the interrelationships can also be used for the metrological determination of material properties: if q is known , the material _property becomes

{\ displaystyle \ Leftrightarrow k_ {f} = {\ frac {k_ {W}} {q_ {f}}}}

with measured force F and area A determined.

In the tensile test , flat compression test and cylinder compression test , approximately constancy is used

{\ displaystyle q_ {f} \ approx 1}

for simple determination of the yield stress or a stress-strain diagram .

Footnotes

↑ The blacksmith at the anvil: A practical textbook for all blacksmiths and locksmiths

literature

Kurt Lange: Forming technology basics . Springer-Verlag, Berlin Heidelberg New York 2002, ISBN 3-540-43686-3 .
Heinz Tschätsch, Jochen Dietrich: Practice of forming technology. Working methods - machines - tools, 9th edition, Vieweg + Teubner Verlag, Wiesbaden 2008, ISBN 978-3-8348-0324-5 .
Franz Sauerwald: Textbook of metal science of iron and non-ferrous metals. Published by Julius Springer, Berlin 1929.

Web links

Terms and parameters in forming technology (accessed on January 6, 2020)
Development of test methods to determine the formability and yield stress of materials based on intermetallic compounds (accessed on January 6, 2020)
Compressive strength (accessed January 6, 2020)
Seals (accessed January 6, 2020)
The influence of the rolling conditions in cold rolling of strip steel (accessed on January 6, 2020)

[1] The blacksmith at the anvil: A practical textbook for all blacksmiths and locksmiths