Method and computer program product for characterising the bending response of a material

A method of characterising a material that comprises the steps of:

• a. providing a sample of the material simply supported between two parallel die supports, said supports having the same edge shape;
• b. bending the sample by providing an external force, F, via a bending knife, said force acting in a plane perpendicular to the plane formed by the centres of the die supports and which intersects the material at the centre line between the die supports, said bending knife extending at least the entire length of the sample;
• c. calculating a cross-section moment, M, of the material using the following equation [1]:
• M
• =
• F
• ·
• L
• m
• ⁡
• (
• β
• 1
• )
• 2
• ·
• cos
• 2
• ⁡
• (
• β
• 1
• )
• [
• 1
• ]
• where F is the applied bending force,
• Lm(β1) is the moment arm, calculated according to the following equation:
• Lm(β1)=L0−(Rk+Rd)·sin(β1)
• wherein β1 is calculated using the following equation [0]:
• β1=Sin−1([L0·Q+√{square root over (L02+(S−Q)2−Q2)}·(S−Q)]/[L02+(S−Q)2]·180/π [0]
• where
• L0 is half the die width,
• Rd is the radius of the die edge,
• Rk is the radius of the knife,
• β1 is the bending angle,
• Q=Rk+Rd+t,
• t is the sample thickness, and
• S is a vertical distance through which the bending knife has been displaced.