Register to reply

Variable K elastic constant ?

by cala
Tags: constant, elastic, variable
Share this thread:
cala
#1
Sep24-03, 04:27 PM
P: 176
Difficult to put the topics on the right place...

Is there any spring (or any physical method) that could have different K elastic constant on one sense of movement than on the other?

For example K = 100 (or another value) when compressing and K = 75 (or another value) when decompressing?
Phys.Org News Partner Physics news on Phys.org
Step lightly: All-optical transistor triggered by single photon promises advances in quantum applications
The unifying framework of symmetry reveals properties of a broad range of physical systems
What time is it in the universe?
wolfgang
#2
Sep28-03, 10:42 AM
P: 17
I think that the simpler spring with variable K elastic constant could be made from rubber.
When you stretch this rubber spring the elastic constant would take a value K (the value of K depends on who hard is the rubber).
On the other hand during the compression of the spring the value of the elastic constant is K=0.
Im not sure if practically a rubber spring could work but theoretically it is possible.
russ_watters
#3
Sep29-03, 01:02 AM
Mentor
P: 22,297
Sorta - if you throw in viscosity or plastic deformation or something like that. If you're hoping to use that to overcome the first law of thermodynamics though, no.

rdt2
#4
Oct2-03, 03:53 PM
rdt2's Avatar
P: 124
Variable K elastic constant ?

Almost any polymer (and some other materials) will have a different (and variable) K in tension from that in compression (except for small strains). Under tension, the polymer chains straighten out and stiffen - under compression they tend to buckle and are less stiff. The effect is called 'tension stiffening'.

Reinforced concrete does something similar - as do most fabrics (wool, cotton, etc)


Register to reply

Related Discussions
Difference between Identical , Equal , Equivalent Calculus & Beyond Homework 9
Hooke's Law and Finding the Constant k Introductory Physics Homework 25
Hidden variable in SR and GR Relativity?.. Special & General Relativity 5
A real number definition involving Bruijn-Newmann constant.. Linear & Abstract Algebra 6
How would it affect our daily lives if Plancks constant were different? Introductory Physics Homework 0