I model a bridge and bearing with " flat slider bearing" command in opensees(3D).
I want use " Velocity and Normal Force Dependent Friction " command for friction model.
μSlow = aSlow*N^(nSlow-1)
μFast = aFast*N^(nFast-1)
μ = μFast - (μFast-μSlow )*exp(-a*udot)
a = α0 + α1*N + α2*N^2
μ is dependent of velocity and vertical force cause to I should have α0(alpha0) , α1(alpha1) , α2(alpha2) , aSlow , aFast , nFast , nSlow
but I can not find these inputs
and I note to references in site and I download under REFERENCE(this are in site opensees) :
[2] Constantinou M.C., Mokha A., Reinhorn A. (1990). "Teflon bearings in base isolation. II: Modeling." Journal of Structural Engineering (ASCE) 1990; 116(2): 455-474
and I cannot download under REFERENCE
[1] Bowden F.P., Tabor D. (1964). "The friction and lubrication of solids – part II." Oxford University Press, London, Great Britain, 1964.
and in first refrence not find α0(alpha0) , α1(alpha1) , α2(alpha2) , aSlow , aFast , nFast , nSlow
please help me????
I need α0(alpha0) , α1(alpha1) , α2(alpha2) , aSlow , aFast , nFast , nSlow ????
Do you have any reference that I find these inputs?