Analysis
Every analysis runs as a server job with progress and Cancel. Before a run the model is checked (unsupported or floating nodes, mechanisms, zero stiffness): problems are listed and clicking one selects the item.
Run (F5) #
F5 solves every combination with one factorization and builds the envelope (with member diagrams). Without combinations it solves the active load case. Large models use the GPU solver on the server when it is faster; the job says which solver ran.
Analysis types #
| Analysis | Where | What you enter | What you get |
|---|---|---|---|
| Linear static | Analyze ▸ Linear static | all combinations, one combination, or one load case; diagrams; solver | displacements, reactions, member end forces, diagram stations |
| P-Δ (second order) | Analyze ▸ P-Δ | combination, iterations, tolerance | second-order results of that combination |
| Modal | Analyze ▸ Modal, Seismic ▸ Modal | number of modes; mass from density and nodal masses | periods, frequencies, participation (90 % check, ASCE 7 §12.9.1), mode shapes |
| Buckling | Analyze ▸ Buckling | reference loads, modes | critical load factors λ and buckled shapes |
| Response spectrum | Seismic ▸ Response spectrum | ASCE 7-22 spectrum (Ss, S1, site class, TL), direction, modes, damping, CQC / SRSS | modal and combined base shear, story demands |
| Time history | Analyze / Advanced | ground motion (upload), scale, direction, modal or Newmark, damping | response histories |
| Pushover | Analyze / Advanced | load pattern, control node, target, hinges (or ASCE 41 hinges) | capacity curve, hinge sequence, performance point |
| Nonlinear buckling, arc length | Advanced ▸ Stability | imperfection, steps | load-displacement path |
| Progressive collapse | Advanced ▸ Robustness | members to remove, combination | alternate-path DCRs |
| Fatigue | Advanced ▸ Robustness | stress history, detail category | rainflow and damage |
| Influence lines | Advanced ▸ Moving | path, response | influence line |
| Floor vibration | Advanced ▸ Service | fn, W, β, occupancy (AISC DG11) | peak acceleration vs limit |
| Harmonic, transient, PSD | Advanced ▸ Forced vibration | load, frequencies or PSD table, damping | response functions |
| Staged construction | Advanced ▸ Construction | stages | results per stage |
| Contact, material nonlinear | Advanced ▸ Specialty | gaps or material laws | nonlinear results |
| Continuum, thermal, fracture | Advanced ▸ Continuum | mesh, material, loads | contour results |
| Section cut | Results ▸ Section cut | plane, combination | resultant forces through the cut |
| Story drift, deflection | Design ▸ Story drift / Wind drift, Analyze ▸ Drift | levels, Cd, Ie, limits | drift checks (Design) |
Second-order effects #
A first-order analysis does not include P-Δ. For design, choose the second-order method in Design ▸ Setup (P-Δ, the direct analysis method or B1-B2): the design job then analyses every design combination that way. Analyze ▸ P-Δ is for looking at one combination's second-order response.
Stale results #
Results belong to the model they were computed for. After any edit the status bar shows (stale); press F5 again. The design results are stale in the same way.