Dear all,
I am a somewhat of a beginner. I only started self-studying continuum mechanics and finite element analysis last year. Nonetheless, I hope to solve a problem characterized by large deformations in a hyperelastic incompressible material, with the possibility of contact.
Hello,
I am trying to construct a matrix using Wendland's Compact-Support RBF as described in the following the paper, http://www.cs.umbc.edu/~rheingan/pubs/smi2001.pdf . In particular, I'm using the C2, d = 3 RBF: (1 - r)^4*(4r + 1). It seems quite simple enough, but none of the matrices I've constructed are positive definite, although Wendland's RBFs guarantee positive definite matrices -- the sparse solver I intend to use requires positive definite matrices.
