hulk78 said:Could somebody please tell me if we can apply young modulus theory to a slinky spring, or can only be applied to a rod when strenched?If possible to apply to the slinky spring, how can we calculate the elasticity of that slinky spring?by the way what is the process by which slinky springs are manufactured?(do they compress a thin metal wire in such a way that it always compresses)
Thanks in advanced
Chestermiller said:Yes. Hooke's law of stress and strain can be applied to express the spring constant of a spring in terms of Young's modulus, the Poisson ratio, and the helix angle in the undeformed state. The basic deformation kinematics is one of shear (twist) at each cross section of the wire. This problem can be analyzed using a strength of materials approach, and does not require a theory of elasticity solution.
No. It's much more complicated than that. First of all, as I said, the basic deformation is not tensile. It is shear between adjacent cross sections of the wire. To figure this problem out, you need to go through an analysis of the kinematics of the deformation, and see how the shear of the cross sections translates geometrically into an axial extension of the helical spring. Then, you also need to go through a failure analysis to determine at what extension, the shear stress is high enough to cause failure of the wire. I've seen an analysis of this problem in a strength of materials book by a guy named Faupel, but I'm not sure whether the book is still in print. Try some Googles to see if you can find an analysis on line.hulk78 said:So based on what you said, can I say that we can apply the Young's modulus to the material of the slinky spring itself and therefore we can see in this graph http://en.wikipedia.org/wiki/File:Metal_yield.svg
that as the limit E tends to 0 the spring gets damaged?
Young's modulus, also known as the modulus of elasticity, is a measure of the stiffness of a material. It represents the amount of stress that a material can withstand before it starts to deform permanently.
Yes, Young's modulus can be applied to slinky springs. In fact, it is often used to characterize the stiffness of a slinky spring. This is because slinky springs behave similarly to other elastic materials, and their stiffness can be described using Young's modulus.
Young's modulus is measured by applying a known amount of stress to a material and measuring the resulting strain. Strain is the amount of deformation that occurs in a material when stress is applied. The ratio of stress to strain is equal to Young's modulus.
The main factor that affects Young's modulus in slinky springs is the material from which the spring is made. Different materials have different values of Young's modulus, which can result in varying levels of stiffness. The thickness and geometry of the spring can also have an impact on its Young's modulus.
Young's modulus is important for slinky springs because it helps to determine their behavior and performance. A higher Young's modulus indicates a stiffer spring, which can have implications for how it stretches, compresses, and vibrates. Knowing the Young's modulus of a slinky spring can also help in designing and selecting the right spring for a specific application.