Abstract
In order to investigate the effect of testing rate on the mechanical properties of ceramics, impact lateral compression tests for Mullite circular tubes were carried out at a velocity of 0.6m/sec. The impact lateral compression strength of Mullite tube was obtained to be σfDy≅213MPa which is about 1.6 times greater than the static lateral compression strength. Dynamic and static FEM analyses were also performed to obtain the distribution of hoop stress, σθ, in Mullite tubes during deformation. The distribution of σθ at the maximum load in impact tests was quite similar to that in static tests, although the magnitude of σθ was different. To examine the relation between the increase of maximum load due to the increase of testing rate and the crack-rate sensitivity of the crack growth resistance of ceramics, a numerical simulation for lateral compression of ceramic tube was carried out. If it can be assumed that tube material is perfectly brittle and crack-rate sensitive, the increase of maximum load due to the increase of testing rate can be expected in lateral compression tests and the larger crack-rate sensitivity causes the greater increase of maximum load.
