ES2_Strength of Materials, Strain and Hooke's Law, Centroid, MOI, Radius of Gyration, Shear and Moment in Beams Flashcards
It is the study of the internal effect of external forces applied to structural members
Strength of Materials
It is also known as Mechanics of Materials
Strength of Materials
Internal loads cause _____ in a body/material
stress
Stresses cause a body to ______ .
deform
SI Units for Stress
N/mm^2, MN/m^2 or MPA
Strength of a material per unit area
Stress
English unit for stress
lb/in^2
The lead to accurately describe and predict the elastic deformation of a body.
Stress
3 Classifications of Stress
Normal Stress, Shear Stress, Bearing Stress
Normal stress develops when a force is applied _______________ to the cross-sectional area of the material
perpendicular
Shear stress is developed if the applied force is _________ to the resisting area.
parallel
Other name for shear stress
tangential stress
The contact pressure between separate bodies.
Bearing Stress
Bearing stress differs from compressive stress, as it is an ______________ caused by compressive forces.
internal stress
The ratio of the change in length caused by the applied force, to the original length.
Strain
Strain is also known as __________
unit deformation
The graph of these quantities with the stress σ along the y-axis and the strain ε along the x-axis is called the ________________.
stress-strain diagram
The linear relation between elongation and the applied axial force was first noticed by Sir Robert Hooke in 1678 and is called _____________.
Hooke’s Law
The constant of proportionality 𝑘 is called the ________________ and is equal to the slope of the stress-strain diagram from O to P.
Modulus of Elasticity 𝑬
The limit beyond which the material will no longer go back to its original shape when the load is removed,
elastic limit
The point at which the material will have an appreciable elongation or yielding without any increase in load.
Yield point
The maximum ordinate in the stress-strain
diagram.
Ultimate strength
It is the breaking strength wherein it refers to
the strength of the material just before it
ruptures/breaks.
Rupture strength
It is defined as the actual stress of a material under a given loading.
Working stress
The maximum safe stress that a material can carry
allowable stress
The allowable stress should be limited to values not exceeding the ________________ .
proportional limit
Since proportional limit is difficult to determine accurately, the allowable stress is taken as either the _____________ divided by a factor of safety
yield point or ultimate strength
Ratio of strength to allowable strength is called _______________
factor of safety
The point in which the region will be perfectly balanced horizontally if suspended from that point.
center of gravity or centroid
Also called the second moment of area, is the product of area and the square of its moment arm about a reference axis.
Moment of inertia
the moment of inertia about the z-axis.
Polar moment of inertia
The distance from an axis at which the mass of a body may be assumed to be concentrated.
Radius of Gyration
A slender structural member designed to support loads applied at various points perpendicular to their longitudinal axis.
Beam
According to determinacy, a beam may be ____________ or __________
determinate or indeterminate.
Beams in which the reactions of the supports may be determined using the equations of static equilibrium (3 available equations)
Statically determinate
If the number of reactions exerted upon a beam exceeds the number of equations in static equilibrium, the beam
statically indeterminate
Stresses caused by the bending moment are known as flexural or bending stresses.
Flexure Formula
Stresses caused by the bending moment
flexural or bending stresses
stress is proportional to the distance 𝑦 from the ________________.
neutral axis (N.A.)
