... uvwVb`bXWbabYu1u 2 u3Vb`bXWbabY1 :2 Small deformation non-linear solid mechanics problems 3 The Finite Element Method Fifth edition Volume 2: Solid Mechanics1 .2. 2 Weak form for equilibrium ... 11 :25 Using the GN 22 formulae, the discrete displacements, velocities, and accelerationsare linked by [see Eq. (18. 62) , Volume 1]un 1 un Átun1 2 1 ÿ 2 Át 2 un1 2 2 Át 2 un ... 1 2 3 4 5 6Tensor (1; 2; 3) 11 22 33 12 23 31 21 32 13Tensor (x; y; z) xx yy zz xy yz zxyx zy xzÃFor simplicity we omit direct damping which leads to the term C~u (see Chapter 17, Volume...