Abaqus Earthquake Analysis

SSI can significantly alter seismic demand. Abaqus supports three SSI modeling levels:

Mesh density rule: Maximum element size should be less than 1/6 of the smallest wavelength of interest. For typical ground motions (max frequency 25 Hz) in concrete (wave speed ~3000 m/s), element size ≤ 20 m – easily satisfied. For steel (wave speed ~5000 m/s), size ≤ 33 m. abaqus earthquake analysis

A 60-second earthquake record in Abaqus/Explicit can require billions of increments. Mitigate with: SSI can significantly alter seismic demand

For implicit analysis, use iterative solvers (*SOLVER, TYPE=ITERATIVE) which are 2-5× faster for large models. For implicit analysis, use iterative solvers ( *SOLVER,

Abaqus will give you an answer—even if that answer is wrong. Earthquake analysis is notorious for mesh sensitivity in tension-dominated elements. A concrete beam that tears in a coarse mesh might survive in a fine mesh due to stress redistribution.

Furthermore, without Rayleigh damping, your model will vibrate forever like a tuning fork. With too much damping, it will absorb the earthquake energy like a sponge. Calibrating damping (typically 2% to 5% of critical) against experimental data is the dark art of seismic simulation.