MACH. ELEMENTS 1

• • The moment of inertia of a rectangle whose base is "b" and height "h" about its base is bh³/3
• Endurance Limit is the maximum stress induced in a material when subjected to alternating or repeated loading without causing failure.
• Strain is the total deformation measured in the direction of the line of stress.
• Elastic Limit is the maximum stress to which a material can be subjected without a trace of any permanent set remaining upon a complete withdrawal of the stress.
• Proof Stress is the minimum stress required to produce a specified amount of permanent set.
• Poisson's Ratio is a property of material which relates the lateral strains to the longitudinal strains.
• The ability of metal to withstand loads without breaking down is strength.
• Ultimate Stress is the maximum stress to which a material may be subjected before failure occurs.
• The ability of material or metal to resist being crushed is called compressive strength.
• The ability of material or metal to resist being crushed is called compressive strength.
• These are strength properties of metals:

  • Tensile Strength
  • Fatigue Strength
  • Torsional Strength
• Shear Strength is the ability of the metal to withstand forces thus following a number of twist.
• Stress is a total resistance that a material offers to an applied load.
• Kinetic Energy is the ability of a moving body to perform work.
• Strain is the deformation that results from a stress and is expressed in terms of the amount of deformation per inch.
• Elasticity is the ability of the material to return to its original shape after being elongated or distorted when the forces are released.
• Elastic Limit is the last point at which a material may be stretched and still return to its undeformed condition upon release of the stress.
• Modulus of elasticity is the ratio of stress to strain within the elastic limit.
• The ability of a metal to withstand forces that cause a member to twist is torsional strength.
• The ability of metal to stretch, bend or twist without breaking or cracking is ductility.
• the property of a material which resist forces action to pull the material apart is tensile strength.
• 140-500 Mpa is the range of the tensile strength of common varieties of cast iron.
• The compression members tend to buckle in the direction of least radius of gyration.
• In testing a material for endurance strength, it is subjected to completely reversed load.
• Residual stress is a stress that is independent of loads.
• During tensile test, a sudden break fits for a glass rod following stress-strain curve(s).
• Residual Stress is the internal stresses that exist in any part of the material that is subjected to temperature and not acted upon by an external load.
• In case of a knuckle joint, the pin is most likely to fail in double shear.
• The maximum stress which is reached during a tension test is tensile strength.
• Ultimate Strength is the strength of a material is that of a stress intensity determined by considering the maximum test load to act over the original area of the test specimens.
• Bend is a test for pipe used for coiling in sizes 2 inches
• Modulus of elasticity if the ratio of stress to the corresponding strain below the proportional limit.
• Elongation is the total amount of permanent extension of the gage length measured after the specimen has fractured and is expressed as percentage increase of the original gage length.
• Torsional Strength is a metal characteristic that withstands forces that causes twisting.
• The hardness of helical and herringbone gear teeth after heat treatment is 210 to 300 Brinell Hardness, for gear and pinion is at 340-350 normal.
• Tensile Strength is the property of a material which resists forces acting to pull the material apart.
• The center of gravity of a solid pyramid or cone with a total height of H is 1/4 H.
• Finding the resultant of two or more forces is called composition of forces.
• Creep is the phenomenon of continuous stretching under load even if the stress is less than the yield point.
• Statement that a given body is in static equilibrium means that the body cannot have any type of motion.