Page 558 - Aircraft Stuctures for Engineering Student

Problems 539

P.12.11 A square element 1234, whose corners have coordinates x, y (in metres)
of (- 1, -l), (1 - l), (1,l) and (- 1 1) respectively, was used in a plane stress finite
element analysis. The following nodal displacements (mm) were obtained:
~1=0.1, ~2=0.3, ~3~0.6,
~4~0.1
~l=O.l, ~2~0.3, ~3=0.7, ~4~0.5
If Young’s modulus E = 200000N/mm2 and Poisson’s ratio v = 0.3, calculate the
stresses at the centre of the element.
Ans. ux = 51.65N/mm2, uy = 55.49N/mm2, rxJ = 13.46N/mm2.