PSAD (Terms)

Bearing Stress

The compressive pressure between two bodies that are pressed against each other

Strain

Deformation per unit length is called:

Poisson’s ratio

When a material elongates, it contracts in the direction perpendicular to the direction of elongation. To determine the lateral deformation, a ratio of lateral to longitudinal strain is used. This ratio is called:

Rigidity

A body’s resistance to deformation is referred to as:

A member’s resistance to deformation relative to its length and is taken as the amount of force required to produce unit deformation is referred to as:

The inverse of flexibility is called:

Hooke’s Law

Which of the following states that up to the proportional limit, a material’s stress is directly proportional to its strain?

The area under the entire stress-strain diagram which is also the amount of energy absorbed by the material per unit volume up to rupture is called:

The area under the stress-strain diagram up to the yield point which is also the maximum energy absorbed by the material per unit volume before it deforms permanently is called:

The ratio of normal stress to normal strain is called:

The ratio of shear stress to shear strain is called:

Stress is not proportional anymore to the strain beyond this point in the stress-strain curve.

Elasticity

the ability of a material to return to its original state after the load that caused its deformation is removed

Breaking down of a material causing plastic deformation after the elastic limit is reached is:

Strain hardening

The region in the stress-strain curve where the strength of the material increases after yielding until the ultimate strength is reached is called:

Relaxation

Long term, time-dependent loss of prestress due to constant elongation of tendons

Pre-tensioning

Method of prestressing where the tendons are stressed prior to pouring of concrete

Post-tensioning

Method of prestressing where the tendons are stressed after concrete has hardened

Concrete tensile strength in flexure/bending

A factor that accounts for deviations of the actual load from the nominal load, for uncertainties in the analysis that transforms the load into a load effect, and for the probability that more than one extreme load will occur simultaneously

A factor that accounts for deviations of the actual strength from the nominal strength due to variations in material strengths and dimensions

Time-dependent permanent deformation of concrete due to sustained loading

Fatigue

A material’s tendency to break after being subjected to repeated cycles of stress

Allowable stress

The largest safe stress that can safely be carried by a material

Factor of safety

The ratio of failure stress and working stress

Isotropic

A material that has identical physical and mechanical properties in all directions at a given point

Orthotropic

A material that has different physical and mechanical properties in all three perpendicular directions at a given point

Homogeneous

A material that has the same physical and mechanical properties on all points

The term that refers to the beginning of plastic deformation where a material starts to break down after the elastic limit is reached

Focus

The place in the Earth’s crust where an earthquake originates

Epicenter

The point on the Earth’s surface that is vertically above the focus