Damage Criteria in Roundheads Armoured With a Single Layer of Cubipod Armor Units

Abstract

The present paper covers the analysis of damage in a single-layer roundhead armored with Cubipods. This study was carried through physical model tests. Firstly, the analysis of the damage in these structures has not been an intensive studied topic. It is normally defined when a piece doesn’t contribute in the stability on the single layer armor and, due to, a new damage criteria was proposed. In addition, vertical and sectorial size of active zone was defined. It could be possible defined three different phases in the evolution of damage due to the homogenous behavior for the roundhead. The most damage sector is 90-135º, and the neighbors, 45-90º and 135-180º, but damage in 45-90º is greater in frequency and value. Also, the dimensionless parameters of roundhead size (Rn, R/H and R/L) are involved in this phenomenon. Besides, the vertical size of active zone is defined in ±1.5Hs since sea water level (SWL), being the wave steepness is the principal parameter involved. It was proposed two level of damage: start of damage (D [%] =0.4) and failure (D [%] =11). Finally, it has been measure the reserve of stability. It is defined like the percentage of wave that the roundhead is able to resists between 2 levels of damage. This parameter allows analyzes the rigid behavior of the roundhead single layer armor. The value of this parameter, except one case, is RE [%] =9. It was conclude that wave steepness is a relevant parameter, when it increased the reserve is reduces.