Structural dynamics
Work through
a complete problem.
Use the course concepts together, choose a model and check its response.
A plant platform that shakes
Decide whether a dynamic problem exists at all, then quantify it.
Reading a free-decay test
Turn a measured decay trace into the damping and the damper the model needs.
Isolating a machine that is already installed
Transmissibility decides the mounts, and the answer is softer, not stiffer.
A pressure pulse on a wall panel
The duration relative to the period decides everything about a short load.
Choosing a time step, and proving it
Stability, accuracy and the demonstration that the step is adequate.
A two-storey frame from first principles
Two masses, two stiffnesses, two frequencies — and a check that they are right.
Lumped or consistent mass
Two defensible mass models that bracket the exact answer from opposite sides.
Three storeys: modes and mass
Read a modal output and decide how many modes the analysis actually needs.
Fitting Rayleigh damping, and checking it
Anchor the damping at two frequencies, then find out what every other mode received.
From modes to base shear
Turn a modal output and a spectrum into a force, then check it is credible.
SRSS or CQC
When modal periods are close, the independence SRSS assumes is not there.
What a spectrum analysis does not tell you
The same building, the same record, two methods, and the gap between them.
Setting up a time-history run
Pick the step from the right mode, count the cost, and demonstrate convergence.
A frame that is allowed to yield
Ductility demand, the strength it buys, and the displacement it does not reduce.
Yield, or isolate
Two ways to survive the same earthquake, and what each does to the building.
Sizing an isolation system
From a target period to a moat width, and the factor of two in between.
A damper retrofit
Size a damper, place it by modal drift, and say what it added.
Designing a tuned mass damper
Choose the mass, and everything else follows — including the sensitivity.
Auditing an analysis you did not run
Six checks in order, on an output that looks entirely normal.
One building, end to end
The whole course applied to a single structure, and the decision it leads to.