apeETABS

ETABS analysis and modeling behavior — element formulations (frame, shell/area, link, tendon), load cases (static linear/nonlinear, modal eigen/Ritz, response spectrum, time history direct/modal, nonlinear staged construction, hyperstatic, buckling), automatic lateral loads (seismic & wind per code), P-Delta, modal participation, diaphragms, constraints, meshing, mass source, materials & hinges, and soil-structure springs. Use to explain WHY ETABS produces a result or how a modeling feature behaves. Triggers on "load case", modal/Ritz, response spectrum, time history, P-Delta, staged construction, auto seismic, auto wind, diaphragm, hinge, nonlinear, damping, mass source, eigenvalue, story drift behavior, meshing, or rigid/semi-rigid. Points into the CSI Analysis Reference Manual, Lateral Loads Manual, and technical notes in reference/.

How ETABS performs code-based design and what the results mean — steel frame, concrete frame, composite beam, composite column, shear wall, concrete slab, steel connection, and steel joist design. Covers the supported design codes (AISC 360-05/10/16/22, ACI 318-08/11/14/19, Eurocode 2/3/4, CSA S16 & A23.3, AS 3600 & 4100, NZS 3101/3404, IS 456/800/11384, NTC, BS, HK CP, TS 500, KBC, SP 16, Chinese) — design preferences/overwrites, D-C (demand-capacity) ratios, capacity/seismic provisions, and how to read or script design through the OAPI. Triggers on design code names, "design check", "utilization", "D/C ratio", "overwrites", "auto-select section", cDesignSteel/cDesignConcrete/ cDesignShearWall/cDesignCompositeBeam, or any cDSt*/cDCo*/cDComp*/cDConc* code interface. Points into the vendor design manuals in reference/.

Drive the CSI ETABS Open API (OAPI) from code — primarily Python via comtypes (COM) or pythonnet (.NET), also VBA/C#. Use to connect to or launch ETABS, build models (points, frames, areas, links, tendons), define materials and sections, set loads/patterns/cases/combos, run analysis, and extract results, and to write or extend the apeETABS Python wrapper in this repo. Triggers on SapModel, cOAPI, cSapModel, cHelper, ETABSv1, comtypes.client, pythonnet, CreateObjectProgID, ApplicationStart, InitializeNewModel, RunAnalysis, Results.JointDispl, .edb, "ETABS API", or any cFrameObj/cAreaObj/cPropMaterial/ cLoadPatterns/cAnalyze/cDesign* method. Bundles the full decompiled API reference (120 interfaces, ~1280 methods) and all enums.

Router/orchestrator for working with CSI ETABS. Use whenever the user works with ETABS — building or scripting models through the OAPI (Python comtypes/ pythonnet, .NET, VBA), interpreting how ETABS applies a design code (AISC, ACI, Eurocode, CSA, AS, NZS, IS, NTC, BS, TS, KBC, SP), or understanding ETABS analysis/modeling behavior (element formulations, load cases, modal, auto seismic/wind, P-Delta). Also triggers on apeETABS (the Python wrapper being built in this repo), .edb files, SapModel, cOAPI/cSapModel, ETABSv1, "ETABS API". This skill points to the right specialized sub-skill.