RolfeBarsom: Evaluation of fracture toughness from sharpy absorption...
In ShinsukeSakai0321/FFS:

1	RolfeBarsom(Cv = 47.5, Sy = 5.14e+08)

`Cv`	Sharpy absorption energy
`Sy`	Yeild strength

In case you do not have the fracture toughness value of a material, you can roughly evaluate it from this command. It is said, this method gives safer side evaluation.

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (Cv = 47.5, Sy = 5.14e+08)
{
    k1c <- sqrt(0.6478 * (Cv * 1e+06/Sy - 0.0098)) * Sy
    return(k1c)
  }