By direct experiment with the extension of a bar, it has been established for many materials that within certain limits the elongation of the bar is proportional to the tensile force.this simple linear relationship between the force and the elongation was first formulated by the English scientist ROBERT HOOK .“it states that when a material is loaded , within certain limit ,the stress is proportional to the strain.”
stress α strain
stress/strain=constant
The ratio of normal stress to normal strain is a constant.this ratio is known as MODULUS OF ELASTICITY or YOUNG’S MODULUS is denoted by E.
E=NORMAL STRESS/NORMAL STRAIN
=TENSILE STRESS/ TENSILE STRAIN
=COMPRESSIVE STRESS/COMPRESSIVE STRAIN
E= σ/e .physically ,young”s modulus represents the stiffness of the material to an imposed load . it”s value is a definite property of a material.the unit of E is that of stress, ie N/M2
No comments:
Post a Comment