Edge stresses in bonded armor system for divertor plates

This paper reports on residual stresses in the interface region which were evaluated for the graphite/copper bonded system. The eigenvalue analysis was performed to investigate the favorable free-edge geometry for the interface. The results for the joint having half-plane free-edge geometry indicated no stress singularity for θ1 ∼120 degrees, where θ1 is the angle between the traction free surface of the graphite and the bonding interface. Thermal stresses in the joint having conical bonding interface with inner and outer free edges were also examined for a sequence consisting of cooling form the brazing temperature and service with a pulsed heat load of 10 Mw/m2-5sec. The normal stress on the bonding interface calculated for graphite was tensile only in the neighborhood of the interface edges. This normal stress decreased but the high stress region expanded during heat loading. The Von Mises stress in the interface edge region decreased without apparent increase in plastic strain at two different times in the thermal cycle