Johnson Holmquist Ceramics

By incorporating the compression and tensile test data johnson holmquist ceramic jh 2 model parameters were estimated for aluminosilicate glass.

Johnson holmquist ceramics.

Kaufmann and grant j mcintosh and todd berstad year 2003. In order to define proper material behavior johnson holmquist ceramics material model for b 4 c and plastic kinematic material model for al6061 t6 4340 steel and epoxy resin was used. The johnson holmquist material model jh 2 with damage is useful when modeling brittle materials such as ceramics subjected to large pressures shear strain and high strain rates. The johnson holmquist model commonly used for cera mic materials was enhanced by riedel and co workers 30 31 leading to the rht model.

The first version of the model jh 1 did not allow for progressive damage of the material. Experimental results for aluminum nitride aln together with data available in the literature indicate that a mohr coulomb criterion and the johnson holmquist model fit the experimental data for failure in a brittle manner whereas the ceramic material exhibited pressure insensitive plastic flow at high pressures. The armor structures were subjected to 7 62 mm ogive nosed steel projectile impact. In recent years johnson holmquist and their coworkers have developed a series of constitutive relations to simulate the response of ceramic materials under large strain high strain rate and high pressure impacting conditions.

The constitutive behaviour of alumina ceramics at high strain rates was quantified using the johnson holmquist material model with damage jh 2 a widely accepted model for brittle materials subjected to high loading rates high pressure and large deformation. The compression tests simulated for verification of determined jh 2 constants and finally validated by conducting the eoi simulations on glass plates to the spherical and cylindrical shaped projectile. The johnson holmquist ceramic constitutive model was first proposed to describe the response of brittle materials to large deformations.