9-Dynamic Analysis Fundamentals for Seismic Design (Response Spectrum-Part-3)

In this video, I will explain about:
• Displacement-Velocity-Acceleration response Spectra
• Combined Displacement-Velocity-Acceleration Spectrum (Tripartite Response Spectrum)
• Pseudo vs true values for velocity and acceleration
Keywords:
seismic design of structures
earthquake engineering
earthquakes
dynamic analysis
SKKU

[@NTC]

this is a great example of free education!

[@ravichandra2261]

kindly do one model in sap for high rise buildings earthquake analysis

[@yudhakr]

Hi Dr. Mohamed
Regarding in an example of 3 different deformation, velocity and acceleration response of 3 SDOF converts into 1 response spectrum with (damping of 2%) starting in 20:40 . I want to ask at the 3 graphs,
at Tn = 0, the deformation also, D = 0, because it was u (relative deformation) = 0 (the system is infinitely stiff)
at Tn = 0, the velocity also, V= 0, because it was u dot (relative velocity) = 0 (the system is infinitely stiff)
but why in the acceleration graph, when Tn = 0, the acceleration (from what I guess, it should be the relative acceleration or (u double dots) that is zero because it is infinitely stiff) equal to PGA (ug double dots)..?
in simplification, when Tn=0(zero), the deformation and velocity are also zero, but not the acceleration..?

[@karemmaged2110]

شكرا يا دكتور

[@mustafaqasimdows1029]

شكراً لك كثيراً

[@amermohammed14]

Thanks

[@mdalishamsurrahman379]

Dear Dr. Mohamed,
I’ve confusion on the velocity and acceleration eq. V = ωD
Where D = Displacement
ω = circular frequency
But, V =Displacement / Time Period = D/t = Dω/(2π) , t = 2π/ω
Same way V = At = A2π/ω
If I Wrong please correct me

[@abdullahkhatib1464]

No this assumes constant speed. the correct equation is u(t)=D*sinωt.dt by taking the derivative with respect to time u'(t)=Dωcos(ωt) and the maximum speed when the cosine is equal 1. Also, u''(t)=-Dω^2sin(ωt) and the maximum acceleration when the sine is 1