Modeling load-depend friction in bearings in Simscape

Hi everyone,

i'm trying to model a five-point double-toggle lever with bearings with load-dependent friction, based on the normal-force (Coulomb, which is constant at any velocity).

I've tried modeling the bearing with the Multibody Interface and Rotational Friction, but i can only add a constant friction torque. When i calculate the torque using the measured normal force of the bearing, I get an algebraic loop. Is it possible to apply a load dependent Torque (Tr = Fr*d/2 = Fn*µ*d/2) and a friction force (Fr = µ*Fn) without creating algebraic loops?

Note on the image below: The force Rij is calculated as R = µ*N and acts opposite to the velocity. If R is transformed to the center, this results in atorque (T = r*R), acting opposite to the velocity.

Best greetings!

Answer 1

[Dhiraj]

clc; clear; % Given values omega = 12.57; G = 1/3; phi = -72*pi/180; % Calculate a a = -omega / tan(abs(phi)); % Calculate b b = G * sqrt(omega^2 + a^2); disp(['a = ', num2str(a)]); disp(['b = ', num2str(b)]);