# 4.2.6.14. FPBearingPTV¶

The FPBearingPTV command creates a single Friction Pendulum bearing element, which is capable of accounting for the changes in the coefficient of friction at the sliding surface with instantaneous values of the sliding velocity, axial pressure and temperature at the sliding surface. The constitutive modelling is similar to the existing singleFPBearing element, otherwise. The FPBearingPTV element has been verified and validated in accordance with the ASME guidelines, details of which are presented in Chapter 4 of Kumar et al. (2015a).

element('FPBearingPTV', eleTag, *eleNodes, MuRef, IsPressureDependent, pRef, IsTemperatureDependent, Diffusivity, Conductivity, IsVelocityDependent, rateParameter, ReffectiveFP, Radius_Contact, kInitial, theMaterialA, theMaterialB, theMaterialC, theMaterialD, x1, x2, x3, y1, y2, y3, shearDist, doRayleigh, mass, iter, tol, unit)
 eleTag (int) unique element object tag eleNodes (list (int)) a list of two element nodes MuRef (float) Reference coefficient of friction IsPressureDependent (int) 1 if the coefficient of friction is a function of instantaneous axial pressure pRef (float) Reference axial pressure (the bearing pressure under static loads) IsTemperatureDependent (int) 1 if the coefficient of friction is a function of instantaneous temperature at the sliding surface Diffusivity (float) Thermal diffusivity of steel Conductivity (float) Thermal conductivity of steel IsVelocityDependent (int) 1 if the coefficient of friction is a function of instantaneous velocity at the sliding surface rateParameter (float) The exponent that determines the shape of the coefficient of friction vs. sliding velocity curve ReffectiveFP (float) Effective radius of curvature of the sliding surface of the FPbearing Radius_Contact (float) Radius of contact area at the sliding surface kInitial (float) Lateral stiffness of the sliding bearing before sliding begins theMaterialA (int) Tag for the uniaxial material in the axial direction theMaterialB (int) Tag for the uniaxial material in the torsional direction theMaterialC (int) Tag for the uniaxial material for rocking about local Y axis theMaterialD (int) Tag for the uniaxial material for rocking about local Z axis x1 x2 x3 (float) Vector components to define local X axis y1 y2 y3 (float) Vector components to define local Y axis shearDist (float) Shear distance from iNode as a fraction of the length of the element doRayleigh (int) To include Rayleigh damping from the bearing mass (float) Element mass iter (int) Maximum number of iterations to satisfy the equilibrium of element tol (float) Convergence tolerance to satisfy the equilibrium of the element unit (int) Tag to identify the unit from the list below. 1: N, m, s, C 2: kN, m, s, C 3: N, mm, s, C 4: kN, mm, s, C 5: lb, in, s, C 6: kip, in, s, C 7: lb, ft, s, C 8: kip, ft, s, C