Relation between mass, stiffness and Damping
Relation between mass, stiffness and Damping
(OP)
Hi,
Will there be any relationship between Mass, Damping and Stiffness. I want to use a 5 node example and I don't know what values should I use for mass, stiffness and damping.
Will there be any relationship between Mass, Damping and Stiffness. I want to use a 5 node example and I don't know what values should I use for mass, stiffness and damping.





RE: Relation between mass, stiffness and Damping
The generic mechanical oscillator system is a mass-spring-damper, and is considered equivalent to a sparky's RLC circuit. Consider a mass suspended from a fixed point by a spring, and a damper (think shock absorber) in parallel with the spring, then the mass m, damping constant c, and spring stiffness k are related by the differential equation
m d2x/dt2 + c dx/dt + kx = f(t), where f(t) is a force vs. time function.
RE: Relation between mass, stiffness and Damping
Wood is "lighter" than water but way stiffer in bending.
RE: Relation between mass, stiffness and Damping
Please. Demonstrate the bent shape of water... :)
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Relation between mass, stiffness and Damping
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Relation between mass, stiffness and Damping
If you take a steel wire, it has more axial stiffness and low mass. If you attach steel ball at the end of the wire. The steel ball has more mass and rigid(High stiffness). Compared to the steel ball, the mass of the wire negligible.
Instead of steel wire, if you use rubber cord, it may have still lower stiffness and better damping.
Logesh
RE: Relation between mass, stiffness and Damping
I want to know how the parameters vary for a bridge. Thanks elogesh
RE: Relation between mass, stiffness and Damping
One more thing I found in many examples is that they are using all the stiffness and damping values as the same for all DOF.
RE: Relation between mass, stiffness and Damping
f0=(1/2pi)*sqrt(Stiffness/Mass).
Damping effect is negligible/unimportant compared to both mass or stiffness, except when the SDOF is near from the resonance frequency. Why ? Because the mass effect is balanced/canceled by the stiffness effect.