Q3 [Total 2 marks] The 3-dimensional state of strain at a material point in x, y, z coordinates is given by: Ex 0 0 0 xy yy [ε]=&yx Ey Eyz =

0 = 0 -1 -3 *104 Ey Ezz 0 -3 5 Ex E (a) Calculate the characteristic equation and determine the principal strains for the three-dimensional state of strain [1 mark]; (b) Calculate the volumetric strain and the deviatoric strain invariants [1 mark].