As shown in Fig 1, a two-dimensional plate is discretised by only using one three-node triangular element, and the plate is loaded as follows. Fig 1: A two-dimensional plate structure If we have already known the strain-displacement matrix [B] and material property matrix [D] and assume that the element thickness is 10 mm, 0 0 2.5 0 2.5 0 0 50 0 0 5 1 5 0 0 2.5 5 2.5 m B , and 11 2 1 0.3 0 2 10 0.3 1 0 0 0 1 0.3 2 N m D (1) Calculate the displacement u occurred at nodal No 2 of the element. (2) Calculate the strain and stress at point A within the element