Experimental and numerical analysis of impact on curved steel- polyurea bi-layer panels

The impact behavior of steel – polyurea bi-layer panel and the effect of curvature is studied numerically and experimental analysis is used for numerical result verification. Numerical analysis for 12 different radius of curvature is performed. On the other hand three radius of curvature is used in experimental analysis. Simple drop weight impact test apparatus is used and the falling weight height is 30 cm. The bi-layer samples in three radius of curvature are fabricated and each sample consisted of steel layer and polyurea coating. Two important parameters measured are the maximum plastic deformation of panel and impactor acceleration history. A high speed accelerometer is used for measuring the impactor acceleration in experimental method. Also the permanent plastic deformation is measured with numerical measurement system attached to the drop test apparatus. LS-DYNA software is used in numerical analysis and explicit solution is done. The results in numerical method and test (if available) are compared together and show good agreement. The results for all cases show that, increasing the panel radius of curvature will increase impactor acceleration and will decrease plastic deformation of bi-layer panel, but if the radius of curvature is increased more and more, then the impactor acceleration will not be increased further and will be nearly constant. On the other hand plastic deformation of the panel will be constant when the panel radius of curvature is increased more