I'm using GAP element with an initial gap (no stiffness values). In FEMAP, i usually check "gaps as contact" to make sure cgap acts as contact element and not spring element. In the last case i ran, i forgot to check "gaps as contact" and still model run fine and cgap acted like contact elements and not springs. I ran the model again with "gaps as contact" checked and the results were same as previous run. Am i missing something here?