PSAD TERMS
It is measured by the Richter scale.
Magnitude of Earthquake
It is measured by a seismometer.
Actual displacement
Besides the epicenter, it describes the location of the earthquake.
Focal depth
The material has the same elastic properties in all directions.
isotropic
The composite material exhibits elastic properties in one direction different from that in the perpendicular direction.
orthotropic
It occurs when the structure's center of mass does not coincide with its center of rigidity.
torsional shear stress
It refers to the displacement of one level relative to the level above or below.
story drift
It occurs when a building period coincides with the earthquake period.
resonance
When a material has to support a load for a long period of time, what causes it to continue to deform until a sudden fracture occur?
creep
The greatest stress that can be applied to an elastic body without causing permanent deformation.
elastic limit
Which of the following refers to the flexibility of a structural system?
inverse of stiffness
Which of the following can be measured by a seismometer?
ground displacement
The distance between the center of mass and center of rigidity.
eccentricity
The point on a structure where the resultant vertical force acts.
center of mass
It is the point through which the resultant of the resistance to the applied lateral force acts.
center of rigidity
The ability of the material to absorb energy in the elastic range.
resilience
Refers to the stress at which a material begins to deform plastically.
yielding
Refers to the tendency of solid materials to return to their original shape after being forces are applied on them. When the forces are removed, the object will return to its initial shape and size.
elasticity
The material composition is the same but its mechanical properties are different in every direction.
orthotropic material
The ability of a material to absorb energy and plastically deform without fracturing.
toughness
The ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed.
elasticity
Tendons are stressed after concrete has hardened.
post-tensioning
Tendons are stressed before concrete is poured.
pre-tensioning
A time-dependent prestress loss in pretensioned concrete.
relaxation
Forces generated by a bodies in motion?
dynamic
Material property which enables it to under large permanent strains before failure?
Ductility
Materials having the same composition at any point are termed as ______________________.
Homogeneous
The portion of the stress-strain curve beyond which the stress no longer proportional to the strain?
Proportional Limit
Within elastic range, the slope of the straight line portion of the stress-strain curve.
Young's Modulus
The ratio of lateral strain to longitudinal strain.
Poisson's ratio
Within proportional limit, the stress is directly proportional to strain.
Hooke's Law
Energy by virtue of velocity.
kinetic
Which of the following forces determines whether a body will be at rest or in motion?
resultant
Which of the following deals with forces at rest?
static
It is the point through which the resultant of the resistance to the applied lateral force acts.
center of rigidity