1920 L.J. vandeperre, 0. 0. Van Der Biest The force required for deformation of this config- load-displacement diagram. Further the apparent uration,is obtained by superposition of the force Youngs Modulus is evaluated from the initial required to deform each of the O-rings and each of slope of the curve. The slope changes in the load the C-rings. After failure of a C-ring, it is assumed displacement diagram due to failure of the layers that no more load is taken by that part of the ring. are then calculated. In Fig. 4 a calculated overlay Figure 8 shows some examples for laminated on an experimental result is shown: the changes in rings having an internal radius of 9.5 mm and an the stiffness observed during the test can indeed be average strength of 430 MPa. The average strength reproduced if the load-displacement diagram is of 430 MPa was selected since the strength of the calculated following the proposed failure events electrophoretically deposited Sic was found to be sequence. It should be noted that sometimes more 430 MPa with a Weibull modulus of 3.7, 13 layers do fail together in real materials since not all If all layers have an equal strength, the failure layers have an equal strength sequence will be as in Fig. 6: first the O-ring will fail layer by layer starting from the inner layer, followed by the failure of the so created C-rings 4 Conclusi tarting from the outside Apart from simulations, the above program can Electrophoretic forming of composite ceramic also be used to evaluate whether the stiffness laminated tubes is possible: SiC/graphite laminated decrease observed during real tests is in accordance tubes can be obtained and the layer thickness can with what is expected based on the above failure be controlled easily mechanism. Since the strength values of the layers Moreover, rings cut from such tubes show grace- are not known a priori, the displacements at which ful failure: cracks are deflected at the graphite inter- failure of a layer occurs are taken from the measured layers, resulting in an increase of the work to failure 20 Displacement (mm) Fig.8. Partial calculated load-displacement diagrams(up to o5 mm displacement) for a laminated ring of unit thickness consisting of 20 SiC layers of 100 um, with a Young s modulus of 450 GPa and an inner diameter of the ring of 9. 5 mm for(a)an average strength of 430 MPa and an infinite Weibull modulus, (b, c d) examples for an average strength of 430 MPa and a Weibull modulus of 3.7