The program solves the differential equation: w = deflection of
the slab [m] x, y = coordinates [m] ks = modulus of subgrade
reaction [kN/m³] q = distributed load [kN/m²] ν = Poisson's
ratio of slab [-] E = Young's modulus [kN/m²] t = thickness of
slab [m] Analytical solutions for this differential equation
only exist for a few special cases. For problems in daily design
practice (with variously distributed loads, freely pivoted,
restrained or supported boundaries, etc.) numerical methods must
be relied on. The differential equation is solved by the program
using finite-element-methods. Triangle elements are used. Simple
assumptions are made for these triangle elements with regard to
displacements. In the present case, a displacement assumption is
used that is described in Zienkiewicz (Carl-Hanser-Verlag, 1984,
Page 236). This displacement approach produces very good results
compared to other approaches. The approach adopted leads to
equation systems with a number of variables corresponding to
three times the