Issue 29

G. Maurelli et alii, Frattura ed Integrità Strutturale, 29 (2014) 351-363; DOI: 10.3221/IGF-ESIS.29.31 363 Figure 17 : Evolution of xx  (normal stress) with time at the upper left corner of the cantilever. R EFERENCES [1] Phan-Thien, N., Understanding viscoelasticity, Advanced Texts in Physics, Springer-Verlag, Berlin, (2002). [2] Bruggi, M., Venini, P., Eigenvalue-based optimization of incompressible media using mixed finite elements with application to isolation devices, Computer Methods in Applied Mechanics and Engineering, 197(13-16) (2008) 1262- 1279. [3] Brezzi, F., Fortin, M., Mixed and hybrid finite element methods, Springer Series in Computational Mathematics. Springer-Verlag, New York, 15 (1991). [4] Rognes, M.E., Winther, R., Mixed finite element methods for linear viscoelasticity using weak symmetry', Math. Models & Methods in Applied Sciences, 20(6) (2010) 955-985. [5] Arnold, D., Winther, R., Mixed finite elements for elasticity, Numer. Math., 92 (2002) 401-419. [6] Carstensen, C., Gunther, D., Reininghaus, J., Thiele, J., The Arnold-Winther mixed FEM in linear elasticity. Part I: Implementation and numerical verification, Computer Methods in Applied Mechanics and Engineering, 197 (2008) 3014-3023. [7] Diaz, A., Kikuchi, N., Solution to shape and topology eigenvalue optimization problems using a homogenization method, Int. J. Numer. Methods Engrg. 35(3) (1992) 1487–1502. [8] Krog, L.A., Olhoff, N., Topology optimization of plate and shell structures with multiple eigenfrequencies, In: N. Olhoff, G.I.N. Rozvany, Proceed. WCSMO-1 First World Congress of Structural and Multidisciplinary Optimization, 675–682, (1995). [9] Pedersen, N.L., Maximization of eigenvalue using topology optimization, Struct. Multidiscip. Optim. 20 (2000) 2–11. [10] Johnson C., Mercier, B., Some equilibrium finite elements methods for two dimensional elasticity problems, Numer. Math., 30 (1978) 103–116. [11] Bruggi, M., Venini, P., A mixed FEM approach to stress-constrained topology optimization, Int. J. Numer. Methods Engrg., 73 (2008) 1693–1714.