_Abaqus_VUMAT (SPRINC)_Problem of calling principal values in VUMAT (vsprinc)

Hi, i have problem with calling the principal values. The principal
values become very big values and make the excessive  element. There are
the coding i'm create as below: Any problem on it??



 







do k = 1, nblock

       

       

       s11(k,1) = stressOld(k,1) + dd11*strainInc(k,1)+

     1      dd12*strainInc(k,2)+ dd13*strainInc(k,3)

         

        s11(k,2) = stressOld(k,2) + dd21*strainInc(k,1)+

     1      dd22*strainInc(k,2)+ dd23*strainInc(k,3)

         

        s11(k,3) = stressOld(k,3) + dd31*strainInc(k,1)+

     1      dd32*strainInc(k,2)+ dd33*strainInc(k,3)

         

          s11(k,4) = stressOld(k,4) + dd44*strainInc(k,4)

       

          s11(k,5) = stressOld(k,5) + dd55*strainInc(k,5)

       

          s11(k,6) = stressOld(k,6) + dd66*strainInc(k,6)





       

      call vsprinc(nblock, s11, eigVal, ndir, nshr)

       



       s1=min(eigVal(nblock,1),eigVal(nblock,2),eigVal(nblock,3))

       s2=max(eigVal(nblock,1),eigVal(nblock,2),eigVal(nblock,3))

       s3=eigVal(nblock,3)

Thanks alot your help and higly appreciate it.