How do I get rid of degradation?
plz ....
set kc 10; #parameter for vertical cavitation
set PhiM 0.5; # Maximum damage index
set ac 1.0; # strength degradation parameter
set cd 0.1; # viscous dampng parameter
set sDratio 0.5; # shear distance ratio
set m 0.0; #mass of the bearing
set Fyl0 [expr (600.
*$KN]; #Yield stress of lead initially set TL1 20; #Initial temperature in Fahrenheit
set qL 11200; #Density of lead in kg/m3
set cL 130; #Specific heat of lead in N-m/Kg oC
set kS 50; #thermal conductivity of steel W/oC
set aS 1.41e-01; #diffusitivity
set A [expr ($p/4)*(($D2)*($D2)-$D1*$D1)]; #Bonded area
set S [expr ($D2*$D2-$D1*$D1)/(4*$D2*$tr)]; #Shape factor
set Tr [expr $n*$tr]; #Total rubber thickness
set h [expr ($Tr+($n-1)*$ts)]; #Total height of bearing
set r [expr $D2/$D1]; #outer to inner diameter ratio
set F [expr ($r*$r+1)/(($r-1)*($r-1)) + (1+$r)/((1-$r)*log($r))]; #diameter modification factor
#For horizontal motion
set uy_h [expr (16)*$mm]; # Yield displacement of elastomeric bearing in horizontal direction
set Fy_h [expr $Fyl0*$p*$D1*$D1/4]; # Yield strength of elastomeric bearing in horizontal direction
set k1 [expr $Fy_h/$uy_h]; #Elastic stiffness of bearing
set k2 [expr $G*$A/$Tr]; #Post-yield stiffness of bearing
set Ccr [expr 0]; #Critical damping
set DampingRatio [expr $cd/$Ccr]; #Damping in the elastomeric bearing
set Ec [expr 1.0/((1.0/(6.0*$G*$S*$S*$F))+(4.0/(3.0*$K)))]; #Compressive modulus of elastomeric bearing
set E [expr 3*$G]; #Elastic modulus
set I [expr ($p/64)*(($D2)**4-$D1**4)]; #Moment of inertia of bearing
set r [expr sqrt($I/$A)]; #Radius of gyration
set Kpre [expr $A*$Ec/$Tr ]; #Pre-cavitation stiffness in Tension
set Kpost [expr $A*$E/$Tr ]; #Post-cavitation stiffness in Tension
set Fc [expr 3*$G*$A]; #Cavitation force
set uc [expr $Fc/$Kpre ]; #Cavitation displacement
set Er [expr $Ec/3]; #Rotation modulus of bearing
set As [expr $A*$h/$Tr]; #Adjusted shear area of bearing
set Is [expr $I*$h/$Tr]; #Adjusted moment of intertia of bearing
set Pe [expr $p*$p*$Er*$Is/($h*$h)]; #Euler buckling load of bearing
set Pcr [expr -sqrt($Pe*$G*$As)]; #Critical buckling load in compression
set ucr [expr $Pcr/$Kpre]; #Critical displacement in compression