{"id":1930,"date":"2021-12-07T17:10:49","date_gmt":"2021-12-07T09:10:49","guid":{"rendered":"https:\/\/www.naxau.cn\/?post_type=docs&p=1930"},"modified":"2023-12-14T10:13:17","modified_gmt":"2023-12-14T02:13:17","password":"","slug":"modulus-of-elasticity-youngs-modulus-modulus-of-elasticity-e","status":"publish","type":"docs","link":"https:\/\/www.naxauam.com\/en\/docs\/modulus-of-elasticity-youngs-modulus-modulus-of-elasticity-e\/","title":{"rendered":"Modulus of Elasticity-Young's Modulus, Modulus of Elasticity, E"},"content":{"rendered":"

<\/h3>\n

Definition of Modulus of Elasticity (Young's Modulus)<\/h3>\n

The modulus of elasticity is the constant of the deformation produced by a given stress acting on a material. According to Hooke's law, for the elastic deformation phase of a material, the stress is directly proportional to the strain.<\/p>\n

Hooke's law is expressed as:<\/p>\n

\u03c3 = E\u03b5<\/p>\n

In the above equation, \"E\" is referred to as the modulus of elasticity, \u03c3 denotes stress and \u03b5 denotes strain.<\/p>\n

We can write an expression for the modulus of elasticity using the equation above:<\/p>\n

E = (F*L)\/(A*\u03b4L)<\/p>\n

Therefore, we can define the modulus of elasticity as the ratio of normal stress to longitudinal strain.<\/p>\n

Modulus of elasticity unit<\/h3>\n

Normal stresses have units of Pascal Pa and longitudinal strains have no units. This is because the longitudinal strain is the ratio of the change in length to the original length. So the unit of modulus of elasticity is the same as the unit of stress, which is Pascal (Pa). We usually use megapascals (MPa) and gigapascals (GPa) to measure the modulus of elasticity.<\/p>\n

How to measure Young's modulus or modulus of elasticity?<\/h3>\n

Let us take an example of a rod of ductile material made of mild steel. Now perform a tensile test on a universal testing machine. After the tensile test, the stress-strain diagram is plotted and the following curve is obtained.<\/p>\n

\"Modulus<\/p>\n

From the curve, from point O to point B, the region is an elastic region. Then, plastic deformation begins. The point A in the curve represents the proportional limit. For this curve, we can write the value of the modulus of elasticity (E) equal to the slope of the stress-strain curve up to A.<\/p>\n

If the value of E increases, the longitudinal strain decreases, which means that the length change decreases.<\/p>\n

Some common sense laws of modulus of elasticity<\/h3>\n

The lower the modulus of elasticity, the greater the relative amount of deformation, the smaller the stiffness, the material is easy to deform the better the flexibility; the higher the modulus of elasticity, the material deformation of the modulus of elasticity is relatively small, the stiffness is large, the material is not easy to deform, the more brittle. Modulus of elasticity can be regarded as a measure of the material to produce elastic deformation of the degree of difficulty of the index, the larger the value, so that the material to produce a certain elastic deformation of the stress is also the greater, that is, the greater the material stiffness, that is, in a certain amount of stress, the occurrence of elastic deformation of the smaller. Apply an external force to the elastomer, the elastomer will undergo a change in shape, called \"strain\".<\/p>\n

Relationship between modulus of elasticity and brittleness<\/h3>\n

Brittle materials are those with elongation less than 3%. And the elastic material refers to the plastic deformation under a certain external force. Brittle materials can be low modulus of elasticity, such as glass, but high modulus of elasticity is not necessarily a brittle material, such as mild steel, alloy steel and so on.<\/p>\n

Other information about modulus of elasticity<\/h3>\n