Comparing the failure behavior of a plate using 3 different materials

Material Property of Law-27:

The material we will be testing is LAW – 27. This material model is like the Johnson-Cook material model along with the brittle failure card. This card is used for modeling brittle materials.

Material card:

The failure criteria are given in the material card are,

EPS_t1= EPS_t2= 0.14(the tensile failure strain starts reducing)

EPS_m1= EPS_m2= 0.15(the tensile failure strain reaches zero)

EPS_f1= EPS_f2= 0.151(the plastic strain at which the elements get deleted)

Damage factor (Dmax) = 0.999

Observations:

• The elements start to fail when the EPS_f value reaches one integration point. There is a slight elasticity seen in the plate before the failure takes place.

• The Hourglass Energy and the Contact energy remains zero because of the Physical stabilization of the hourglass.
• The Internal Energy of the plate increases linearly due to the absorption of the Kinetic Energy from the impacting sphere.

• Since the elements are getting deleted there is a noise in the graph. Towards the end of the curve, there is a sudden hike due to the deletion of a big chunk of an element.

Conclusion:

The best case for on-field scenario totally depends upon the scenario, i.e, if the brittle material must be studied then Law-27 is the best, whereas, to study an elastic material Law-1 would be suitable. We can employ the same procedure to analyze the failure behavior of other materials such as elastoplastic, elastic material, etc. and decide the best material for a piece of equipment.