During the last years carbon-based nanostructures (such as, fullerenes, carbon nanotubes and graphene) have been object of intense investigations. The great interest in these nanostructures can be attributed to their remarkable electrical and mechanical properties. Their inorganic equivalent structures do exist and are based on boron nitride (BN) motifs. BN fullerenes, nanotubes and single layers have been already synthesized. Recently, the fracture patterns of single layer graphene and multi-walled carbon nanotubes under stress have been studied by theoretical and experimental methods. In this work we investigated the fracturing process of defective carbon and boron nitride nanotubes under similar stress conditions. We have carried out fully atomistic molecular reactive molecular dynamics simulations using the ReaxFF force field. The similarities and differences between carbon and boron nitride fracture patterns are addressed. © 2013 Materials Research Society.1526 1217Novoselov, K., Geim, A., Morozov, S., Jiang, D., Zhang, Y., Dubonos, S., Grigorieva, I., Firsov, A., (2004) Science, 306, p. 666Nakada, K., Fujita, M., Dresselhaus, G., Dresselhaus, M.S., (1996) Phys. Rev. B, 54, p. 17954Barone, V., Peralta, J., (2008) Nano Letters, 8, p. 2210Li, X., Wang, X., Zhang, L., Lee, S., Dai, H., (2008) Science, 319, p. 1229Han, M.Y., Ozyilmaz, B., Zhang, Y., Kim, P., (2007) Phys. Rev. Lett., 98, p. 206805Campos-Delgado, J., Romo-Herrera, J.M., Jia, X., Cullen, D.A., Muramatsu, H., Kim, Y.A., Hayashi, T., Smith, D.J., (2008) Nano Lett., 8, p. 2773. , YJiao, L., Zhang, L., Wang, X., Diankov, G., Dai, H., (2009) Nature, 458, p. 877Kosynkin, D.V., Higginbotham, A.L., Sinitskii, A., Lomeda, J.R., Dimiev, A., Price, B.K., Tour, J.M., (2009) Nature, 458, p. 872Erickson, K., Gibb, A., Sinitskii, A., Rousseas, M., Alem, N., Tour, J., Zettl, A., (2011) Nano Letters, 11, p. 3221Zeng, H., Zhi, C., Zhang, Z., Wei, X., Wang, X., Guo, W., Bando, Y., Golberg, D., (2010) Nano Letters, 10, p. 5049Dos Santos, R.P.B., Perim, E., Autreto, P., Brunetto, G., Galvao, D., (2012) Nanotechnology, 23, p. 465702Van Duin, A., Dasgupta, S., Lorant, F., Goddard III, W., (2001) The Journal of Physical Chemistry A, 105, p. 9396Plimpton, S., (1995) Journal of Computational Physics, 117, p. 1Zang, A., Stephansson, O., (2009) Stress Field of the Earth's Crust, , Springer, BerlimGarel, J., Leven, I., Zhi, C., Nagapriya, K.S., Popovitz-Biro, R., Golberg, D., Bando, Y., Joselevich, E., (2012) Nano Lett., 12, p. 6347