Lesson 4-5: (P2) Dynamics of Vibration, Attenuation and Time History

Question 1

2 seismic design approaches

Answer 1

• static analysis
• dynamic analysis

Question 2

formulated by estimating an equivalent lateral seismic loads as a fraction of the total system weight

Answer 2

static analysis

Question 3

the fraction is determined from a notional earthquake, which is based on the risk posed by the seismicity of the site and is captured in a single graph known as the _____

Answer 3

response spectrum

Question 4

the procedure for this analysis models the load effect of earthquakes more accurately by using either a set of specific earthquake ground motion time history records (response time-history analysis procedure) or the effect of same notional earthquake as the equivalent static analysis (the design response spectrum)

Answer 4

dynamic analysis

Question 5

this variable, along with the mass, is needed to determine the circular frequency, which once obtained can be used to determine the natural period of vibration of the system

Answer 5

structural stiffness (k)

Question 6

defined as the ratio of force (or moment) to displacement (or rotation)

Answer 6

stiffness

Question 7

it is central to the understanding of vibration theory

Answer 7

DOF

Question 8

an independent displacement or rotation of a point on a structure, which means that even the simplest case could potentially have an infinite number

Answer 8

DOF

Question 9

determination of DOFs depends on the _____

Answer 9

idealization of the structural system

Question 11

often points of interests of DOF

Answer 11

ends of a member

Question 12

caused by initial conditions (displacement and velocity) and not by applied force

Answer 12

free vibration

Question 13

2 theories of free vibration response of undamped systems

Answer 13

• application of equilibrium equation to FBD using D’Alembert’s principle
• Newton’s 2nd law, F = ma.