urti insulation

[giotama]

I ask you a question about which I'm a little nervous and I can't find the fundamentals of theory on which to base this type of analysis:
I try to make it easier: Suppose we have a steel plan and a hammer. if with the hammer beat on the army plane a force f that considering the stiffness both of the hammer and of the plan is transmitted integrally to the steel plane... but if between plane and hammer I interpose a layer of rubber thickness s and shore hardness date, how do I determine how much of the f force is transmitted to the plane and how much is dissipated by the damping effect of the rubber?

thank you in advance to those who will give me some ideas!

 

[rero]

I think you should check if you find any catalog of antivibrants or decelerators, in practice they are objects that fulfill the task you are asking. Usually there are formulines (if you like to find some website that t ifa calculation automatically) to calculate the energy you need to absorb. there are various types: hydraulics, spring and rubber.
I'll send you an mp with the best brands.
Hi.

 

[giotama]

Thanks, great idea... I'm looking for some catalog on the internet.. .

 

[gerod]

impulsive dynamics.
I don't remember much but you have to write the law and put the dampener in the case of rubber.
Of course the absorption of energy is to be determined according to characteristics of the material.

 

[AngeloB]

I didn't, but I would.
schaum> resistance of materials (william a. nash) 345 exercises solved > chapter16 methods of deformation energy > the problems of Saint venant beams solved with the energy of internal deformation of the bodies.
Hi.

 

[Fulvio Romano]

I ask you a question about which I'm a little nervous and I can't find the fundamentals of theory on which to base this type of analysis:
I try to make it easier: Suppose we have a steel plan and a hammer. if with the hammer beat on the army plane a force f that considering the stiffness both of the hammer and of the plan is transmitted integrally to the steel plane... but if between plane and hammer I interpose a layer of rubber thickness s and shore hardness date, how do I determine how much of the f force is transmitted to the plane and how much is dissipated by the damping effect of the rubber?

thank you in advance to those who will give me some ideas!

the problem is bad place, the forces do not dissipate.

to the impact, you have a certain speed, this speed becomes zero in the space where the two materials deform. knowing this space you can know the time of arrest, and therefore deceleration and therefore force.

Of course, calculating the stop space is anything but trivial, although intuitively the gommino deforms more, it puts more time, acceleration decreases and with it strength.

take into account, that in all practical cases in which tests of this type are made (e.g. tests of breakage of motorcycle helmets) you do not consider strength, but energy, which is independent from materials that "urtate"

 

[Fulvio Romano]

or try to use the impulse concept of a force, pulse = mass * speed, i.e. the variation of the amount of motion. It's a concept I've never understood how to use practically. . .
http://it.wikipedia.org/wiki/ pulse_(physics))

 

[giotama]

Why do you say the forces don't dissipate? the cycle of elastic hysteresis of a rubber spring is very wide and the difference between the work of load and the release of the spring represents a dissipation that among other things manifests with a strong heated rubber... or did I take a bark?

 

[zeigs]

you are confusing strength and energy: that which dissips in the cycle of hysteresis is energy, that is a force for a shift. the force is always that, but changes the elastic response of the rubber depending on how the force is applied (the shift that is obtained if subjected to that force), from which the cycle of hysteresis and the energy dissipated (the area of the cycle) :4410:

 

[zeigs]

or try to use the impulse concept of a force, pulse = mass * speed, i.e. the variation of the amount of motion. It's a concept I've never understood how to use practically. . .
http://it.wikipedia.org/wiki/ pulse_(physics)

There is a small inaccuracy: pulse = mass * speed change

a practical example could be the verification of a braking system: I have a moving object at a given speed, I know that the force that I am able to transmit is this (maximum friction, effort transmitted by the structure, etc.), how long does the object stop?
usually you do not use the variation of the amount of motion but the energy dissipated because I care to check how much space stops, more than the time in which it does, but I can imagine cases in which time affects

Hi.

 

[Fulvio Romano]

There is a small inaccuracy: pulse = mass * speed change

Yes, yes, just what you say, but I meant that an object that from v1 speed passes to zero (as in the case in question) has a speed delta equal to v1, so I had written "speed"

a practical example could be the verification of a braking system: I have a moving object at a given speed, I know that the force that I am able to transmit is this (maximum friction, effort transmitted by the structure, etc.), how long does the object stop?
usually you do not use the variation of the amount of motion but the energy dissipated because I care to check how much space stops, more than the time in which it does, but I can imagine cases in which time affects

Hi.

In fact, for these accounts I would use the energy that is much more intuitive...but it does not help in the case of shocks

 

[zeigs]

It was clear what you meant, I just wanted to put the dots on the i.

as regards shocks, the impulse lies at the basis of their physics (http://it.wikipedia.org/wiki/urto): the global kinetic energy is preserved during the shock and the two masses exchange equal and contrary impulses (read also preserves the amount of motion). only with energy would I miss an equation

another field in which the impulse is considered fundamental, even if it knows of physics laboratory, are vibrations: Several times I have seen these characters climbed on structures and take them to hammers, the coolest using instrumental hammers (which measure precisely the impulse given by hammered so as to have also a quantitative measure as well as quality of the structure). This is because any solicitation can be decomposed in a series of successive impulses, so if I know the response to an impulse I can extrapolate the response to any stress by overlapping the effects, and because the impulse, by its definition, has an infinite harmonic content (contains all frequencies).
I am going