Why rubber is more tough than steel?

Answer 1

Elasticity is the capability of an object to return to its former shape once a load inducing strain is removed. If you were to drop a steel ball on a very hard surface, it would probably bounce higher than that of rubber. If you drop it on a softer surface, because it would deform less, then the surface it is to bounce off will be the one deforming, so the bounce would be a function of the elasticity of the floor, not of the ball.

A strand of silk is indeed stronger than a steel wire of the same diameter. The reason is that metal uses metallic bounds which is not as strong as the covalent bounds in a macro-molecule like the ones in silk. This also explains why Kevlar, carbon fiber, and carbon nanotubes are also stronger than steel.

Youngs Modulus of steel is more than youngs modulus of rubber

Answer 2

elasticity is the property of a material when it tries to regain its shape and not get deformed much,rubber gets deformed easily while we require high deforming force for steel, thas why steel is more elastic

Answer 3

In order to compare a physical characteristic of two materials a numerical quantification is needed.

Considering a bar of material of length L0 and cross section A0, let us image to extend it up to a length L>l0. The force F the material generate to contrast the extension in elastic regime is proportional to L by the formula

F=A0 E L/L0

where E is the so called Young module and is a measure of the material elasticity.

Greater the Young module greater the force exerted, more difficult to deform the material.

A table of young modules of different materials is reported below, where it can be seen that standard rubber is one of the normal materials with the smallest Young module.

Material

GPa

Rubber (small strain)

0.01--0.1

PTFE (Teflon)[citation needed]

0.5

Polystyrene

3-3.5

Nylon

2--4

Pine wood (along grain)[citation needed]

9

Oak wood (along grain)

11

High-strength concrete

30

Aluminum

69

Glass (see chart)

50--90

Mother-of-pearl (nacre, largely calcium carbonate) [15]

70

Brass

100--125

Bronze

96-120

Titanium (Ti)

Copper (Cu)

117

Wrought iron

190--210

Steel (A36 type)

200

Molybdenum (Mo)

329

Tungsten (W)

400--410[3]

Diamond (C)

1220

Another possible way of comparing the elasticity is to consider the border of elastic regime. As a matter of fact, if the force applied to the material is too strong, the material is no more elastic, the formula above is no more valid and part of the extension imposed to the bar does not disappear at the end of the application of the external force, but remains as a permanent deformation.

This maximum force that divide the elastic regime from the so called plastic one (when part of the deformation remains permanent) is called plastic edge.

Under this point of view, steel has a plastic edge much higher than rubber, since it is needed a much higher force to induce a permanent deformation in steel with respect to rubber.

A Table of values of the plastic edge is reported below

Material

Plastic Edge on unit surface (MPa)

Carbon steel 1090

841

Human skin

20

Titanium 11 (Ti-6Al-2Sn-1.5Zr-1Mo-0.35Bi-0.1Si), Aged

1040

Steel, API 5L X65

531

High-density polyethylene (HDPE)

37

Polypropylene

19.7-80

Cast iron 4.5% C, ASTM A-48

200

Beryllium 99.9% Be

448

Y

483

Polyester resin (unreinforced)

Copper 99.9% Cu

220

Brass

550

Tungsten

1510

Glass

33

Marble

15

Concrete

3

Carbon fiber

1600 for Laminate,

Human hair

380

Bamboo

350-500

Spider silk (See note below)

1000

Aramid (Kevlar or Twaron)

2757

Pine wood (parallel to grain)

40

Bone (limb)

130

Nylon, type 6/6

75

Epoxy adhesive

12 - 30

Rubber

15

Sapphire (Al2O3)

1900

Boron Nitride Nanotube

33000

Diamond

2800

Answer 4

Elasticity is the capability of an object to return to its former shape once a load inducing strain is removed. If you were to drop a steel ball on a very hard surface, it would probably bounce higher than than rubber. If you drop it on a softer surface, because it would deform less, then the surface it is to bounce off will be the one deforming, so the bounce would be a function of the elasticity of the floor, not of the ball.

A strand of silk is indeed stronger than a steel wire of the same diameter. The reason is that metal uses metallic bounds which is not as strong as the covalent bounds in a macro-molecule like the ones in silk. This also explains why Kevlar, carbon fiber, and carbon nanotubes are also stronger than steel.

Youngs Modulus of steel is more than youngs modulus of rubber

DHOPE

IITB

dhope12@gmail.com

Answer 5

Elasticity is measured as Young's Modulus (a.k.a Modulus of Elasticity).

Young's Modulus is equal to the maximum stress that can be placed on an object that will not PERMANENTLY alter the shape of the object over the strain (think deformation) induced by that stress.

************** Elasticity is a Measure of Stress/Strain **********************

Larger stress with little strain = more "elastic"

So,

A steel ball can undergo a large amount of stress with very little stain induced.

A rubber ball on the other hand will show a larger amount of strain (deformation) with a smaller amount of stress placed on it.

Example:

The stress-strain curve below shows steel compared to a polymer and a rubber. As you can see, steel can have a lot of stress placed on it with little deformation while rubber has large deformation with little stress.

Answer 6

In very general terms...

In engineer-speak, toughness means the amount of plastic deformation a material can withstand before it fails, or breaks.

This doesn't imply that rubber can support greater forces or withstand greater stresses. It just means that it can take more punishment before it breaks.

Answer 7

Because of the material and chemicals it be made of.