What Is Response Spectrum Analysis in Seismic Design?
Response spectrum (the ASCE 7 12.9 — the modal; the RSA) analyzes (the modes' — the combined; the SRSS/CQC's) the structure (the 3D's — the dynamic; the irregular's). The analysis: the spectrum's (the SDS/SD1's — the design's), the modes' (the 90%' — the mass's; the combined), and the scaling (the 100%' — the ELF's; the 12.9.4's). The seismic's — the dynamic standard.
Best price · Quotes back fast · PE stamps backed by Apex Grid Engineering
How RSA works
The modes (the shapes' — the periods'; the 90%' — the mass's), the spectrum (the Sa's — the period's; the damped's — the 5%), the combination (the SRSS's — the separated; the CQC's — the coupled), and the direction (the 100/30 — the orthogonal's; the 12.5's).
The requirements
The 90% (the mass's — the modes'; the 12.9.1's), the scaling (the 100% ELF — the 12.9.4's; the base shear's), the 3D (the model's — the required; the torsion's), the diaphragm (the flexible's — the modeled; the semi-rigid's), and the drift (the Cd's — the amplified; the checked).
Vs. the alternatives
The ELF (the equivalent's — the regular's; the simple), the NRHA (the history's — the nonlinear; the tall's), the pushover (the static's — the evaluated), and the selection (the irregular's — the RSA's; the SDC D's). The RSA is the workhorse — the modes combined, the spectrum applied.
The bottom line
Run response spectrum analysis per ASCE 7 12.9 (90% mass participation, SRSS/CQC modal combination, scale to 100% ELF base shear) for irregular or SDC D+ structures.
Torch Engineering PLLC · (480) 490-0064 · info@torchengineering.com — PE stamping backed by Apex Grid Engineering.