source code for stiffness analysis
 

source code for stiffness analysis
many texts have the source code for this type of analysis. you simply have to be willing to learn and apply in order to expound on the code. some that come to mind are:
matrix structural analysis - sack
computer analysis of structural systems - fleming
structural analysis - hibbeler
depending on the author and time of publication many of these texts have code for fortran or basic.
i'm sure there are many more.