Will truss linkages diminish vibrations?

[Varadha]

Is it possible to have a body supported by truss linkages and isolate them from any stresses and impulses?

Say, we are supporting a platform on the top of a set of rigid, pin jointed and cross-linked members. If small impulses act on the bottom on the linkages(upwards), is there any possibility that the impulse does not reach the platform on the top?? Or will there be a significant reduction in its magnitude?

 

[etudiant]

Difficult to see why, unless you factor in real world effects such as slippage and flex between the truss joints.
If the assembly is 'rigid', impulses will be faithfully transmitted. So there must be loss elements in the truss if the impulse is to be attenuated. These can be elastic mountings, hydraulic bumpers or whatever, but their role is to absorb the impulse before it impacts the platform.

 

[Baluncore]

Analyse the structure as a transmission line network.
Design a structure that sounds dead and does not ring like a bell when hit.
You can reduce the impulse amplitude in a number of ways.
1. Have many different path lengths to spread the pulse in time.
2. Use knee joints = 90° bent members to prevent axial P wave propagation.
3. Load with lumped mass near the middle of truss members to reflect impulse energy.
4. Use a plastic sleeve on the pins in the joints. Acoustic mismatch reflects energy.
5. Mix your materials, bamboo, wood or aluminium all sound different to steel.
6. Use a tensegrity structure. http://en.wikipedia.org/wiki/Tensegrity

 

[Varadha]

Thanks guys for that..I am now looking for any online app for testing/simulating my truss-bridge. Is there any free app with decent features?

 

[alphy]

Truss linkages can be effective in diminishing vibrations, but it ultimately depends on the design and construction of the truss system. The purpose of truss linkages is to distribute and transfer forces and loads evenly throughout the structure. This can help to reduce the impact of external forces, such as small impulses, on the platform.

However, it is important to note that truss linkages are not completely isolated from stresses and impulses. While they may help to reduce the magnitude of these forces, they are still subject to the laws of physics and will experience some level of stress and vibration.

In order to effectively isolate a body from stresses and impulses, additional measures such as damping systems or shock absorbers may need to be incorporated into the design. It is also important to carefully consider the materials and construction techniques used in the truss linkages in order to ensure their effectiveness in reducing vibrations.

Overall, truss linkages can play a role in diminishing vibrations, but they should not be relied upon as the sole means of isolating a body from stresses and impulses. Proper design and construction, along with additional measures as needed, should be taken into consideration to effectively reduce vibrations and protect the body from external forces.