Quickfem currently uses planar constraint strain triangle elements (CST).  CST elements are the simplest planar elements to create, solve and understand, and as such are ideally suited to FEA on mobile platforms.

The main limitation of CST elements is that they are overly stiff in bending, however, this can be addressed by increasing the number of elements in your FEM until convergence is achieved.

The example below is the Quickfem implementation of the example problem from Finite Element Modeling for Stress Analysis, 1st Ed, by Robert D. Cook.   The exact solution is calculated from beam theory with included terms from shear deformation mode.

The model can be created yourself in Quickfem easily.  Initially the coarse model with only 10 elements shows a y displacement of 0.251 which is a long way from exact solution of 1.031.  However, once the number of elements is increased to 8 elements through the “beam” depth, reasonable displacement accuracy is achieved to within 5%.  16 elements through the depth is within 2%.



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