HS small spreadsheet?

Question

Dear all, 
 Plaxis HS small gives us the modulus reduction curves as shown below. However, it does not give the values in tabular form. Is there any spreadsheet available to obtain the values of the curves given by plaxis?

Vasileios Basas · Answer

Hi Jamal, 
 Indeed the values are not given in a tabular form. However, they can be obtained using the equations mentioned in Chapter 7 of the Material Models Manual.

Dennis Waterman · Answer

Dear Jamal, 
 1) The tangent curve doesn't change with Eur, apart from the fact that Eur is the cut-off of the stiffness reduction curve, so with a different Eur the strength reduction curve is only cut off at a different point. But the equation of the strength reduction curve does not contain Eur. The secant curve is of course an average stiffness over a strain interval, so that indeed changes starting from the cut-off by Eur. But again, until the cut-off the secant curve is independent of Eur. So you have to be sure what curve literature gives you: a tangent curve or a secant curve.... 2) I have the feeling you're mixing two things. The parameter combination G0 + gamma_0.7 describe the shape of the curve. The graph above only indicate where in the small strain range one can find loose sand and dense sand: the indicated lines are not parameters that describe the curve. On the other hand, if you would have a different value like gamma_0.2 instead of gamma_0.7 it is not so difficult to fill in the HSsmall model a gamma_0.7 and calibrate it to match your gamma_0.2. Or you do it in a spreadsheet if you find that easier. Hence, there is no need for other input parameters as the would just describe another point on exactly the same stiffness degradation curve. 
 With kind regards, 
 Dennis Waterman

Dennis Waterman · Answer

Dear Jamal, 
 For any kind of curve in geotechnics it's almost impossible to match the entire curve. So as you say, the best fit is determined in the area of interest. 
 With kind regards, 
 Dennis Waterman