{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp03_full320_20260801","cell_id":"invariant_mode_decomposition_design__engineering_design","trajectory_id":"R","attempt_index":0,"archetype_slug":"invariant_mode_decomposition_design","domain_slug":"engineering_design","decision":"CANDIDATE","problem_id":"hidden_coupled_aeroelastic_flutter_mode","causal_lever_id":"consequence_weighted_flutter_mode_control","proposal":{"problem":"A lightweight flexible wing can satisfy coordinate-level displacement, strain, and static-margin limits while a coupled bending-torsion mode loses damping as airspeed rises. The independently recognizable design problem is late detection and poor mitigation of aeroelastic flutter because failure develops in a combination of structural and aerodynamic states rather than in any single measured coordinate.","actors_substrate":["airframe structural and aeroelastic engineers","flight-control engineers","test pilots and test personnel","aircraft occupants and people beneath the flight path","flexible wing, actuators, aerodynamic loads, finite-element model, and test sensors"],"observable_state":"Across bounded airspeed and configuration points, measured accelerations, strains, control-surface states, and model states show a coupled oscillatory pattern whose estimated damping approaches zero even though individual channels remain below ordinary limits.","consequence":"An inadequately observed bending-torsion mode may become self-exciting, causing divergent vibration, structural damage, or loss of control.","affected_objective":"Demonstrate adequate flutter margin and select effective structural or control changes without adding unnecessary mass or relying on unsafe full-envelope trials.","structural_mapping":[{"archetype_element":"coupled transformation","domain_realization":"A local aeroelastic state matrix maps structural displacement, velocity, aerodynamic-lag, and actuator states into their rates at a specified airspeed and configuration.","claim_kind":"INFERENCE"},{"archetype_element":"hidden action-relevant invariant direction","domain_realization":"A bending-torsion eigenvector can combine individually modest sensor coordinates while its eigenvalue indicates declining damping.","claim_kind":"HYPOTHESIS"},{"archetype_element":"modal intervention","domain_realization":"Structural stiffness, mass balance, damping, sensor placement, or feedback gains are ranked by their effect on the hazardous mode and on safety outcomes.","claim_kind":"HYPOTHESIS"},{"archetype_element":"bounded modal validity","domain_realization":"Each decomposition is trusted only near its modeled airspeed, loading, configuration, and oscillation-amplitude window.","claim_kind":"INFERENCE"},{"archetype_element":"residual visibility","domain_realization":"Measured responses reconstructed from retained modes are compared with raw test responses so omitted dynamics remain visible.","claim_kind":"INFERENCE"}],"component_map":[{"component":"Transformation Scope","status":"direct","domain_realization":"Linearized aeroelastic operator for a declared airspeed, loading, control law, and configuration."},{"component":"State-Vector Definition","status":"direct","domain_realization":"Structural positions and velocities, aerodynamic-lag states, and actuator/controller states with traceability to sensors and model degrees of freedom."},{"component":"Invariant Mode Basis","status":"direct","domain_realization":"Complex aeroelastic mode shapes, including coupled bending-torsion directions."},{"component":"Modal Gain Spectrum","status":"direct","domain_realization":"Complex eigenvalues expressed as frequency and growth or damping rate."},{"component":"Dominant Mode Selection Rule","status":"adapted","domain_realization":"Retain modes whose damping margin, consequence-weighted sensitivity, or reconstruction contribution crosses a preregistered threshold."},{"component":"Stable/Unstable Mode Partition","status":"direct","domain_realization":"Modes classified as damped, marginal, or growing at each operating point."},{"component":"Modal Intervention Map","status":"direct","domain_realization":"Sensitivity of hazardous-mode damping and outcome metrics to stiffness, mass balance, damping, sensor, and controller changes."},{"component":"Reconstruction Residual Check","status":"direct","domain_realization":"Out-of-sample error and structured residual between measured response and retained-mode reconstruction."},{"component":"Mode Drift Monitor","status":"direct","domain_realization":"Track mode shape, frequency, and damping across airspeed and configuration increments."},{"component":"Interpretation Scope Contract","status":"direct","domain_realization":"Document validity bounds, uncertainty, non-causal interpretations, and forbidden extrapolations."},{"component":"Mode-Coupling Register","status":"direct","domain_realization":"Record near-degenerate modes, non-orthogonality, control cross-effects, and identity swaps."},{"component":"Local Linearization Window","status":"direct","domain_realization":"Declared bounds on airspeed, amplitude, loading, configuration, and control law."},{"component":"Spectral Gap Threshold","status":"adapted","domain_realization":"Minimum frequency/damping separation and mode-identification confidence required to treat retained modes as distinguishable."}],"mechanism_dispositions":[{"slug":"eigendecomposition_workflow","disposition":"selected_load_bearing","contribution_type":"CORE_CAUSAL","adaptation_or_rejection":"Decompose the explicit local aeroelastic state matrix at each bounded operating point to obtain the complete complex modal spectrum.","counterfactual_removal":"Without it, the coupled dynamic directions and their damping trends are not identified from the design model."},{"slug":"modal_sensitivity_sweep","disposition":"selected_load_bearing","contribution_type":"CORE_CAUSAL","adaptation_or_rejection":"Perturb feasible design and control parameters and rank their effect on hazardous-mode damping and safety metrics while logging cross-effects.","counterfactual_removal":"Removing it leaves modes descriptive and provides no defensible map from design choices to flutter margin."},{"slug":"modal_stability_analysis","disposition":"selected_load_bearing","contribution_type":"CORE_CAUSAL","adaptation_or_rejection":"Classify complex modes by growth rate inside each declared local window.","counterfactual_removal":"Without the stability partition, the analysis cannot distinguish a harmless oscillatory mode from one approaching divergence."},{"slug":"mode_shape_testing","disposition":"selected_load_bearing","contribution_type":"TEST_DESIGN","adaptation_or_rejection":"Use bounded ground-vibration or subscale wind-tunnel excitation to validate predicted mode shapes, frequencies, and damping.","counterfactual_removal":"Model-only modes could reflect incorrect joints, damping, or boundary conditions, hard-gating safe reliance on the result."},{"slug":"network_spectral_centrality_analysis","disposition":"incompatible","contribution_type":"NONE","adaptation_or_rejection":"Node-importance ranking does not estimate aeroelastic dynamic stability or identify bending-torsion modes.","counterfactual_removal":"Its removal does not change the causal chain."},{"slug":"power_iteration_probe","disposition":"considered_rejected","contribution_type":"NONE","adaptation_or_rejection":"A dominant-only estimate is unsuitable near mode crossings, where several complex modes and small separations must be resolved.","counterfactual_removal":"Complete eigendecomposition already supplies the required spectrum; removal has no effect."},{"slug":"principal_component_analysis","disposition":"considered_rejected","contribution_type":"NONE","adaptation_or_rejection":"Variance directions in measured data need not be dynamic invariant directions or reveal low-amplitude unstable modes.","counterfactual_removal":"Removing PCA does not affect model-based stability identification or empirical mode validation."},{"slug":"reduced_order_model","disposition":"considered_rejected","contribution_type":"NONE","adaptation_or_rejection":"A runnable surrogate may help later control design but is unnecessary for the first identification and mitigation-ranking test.","counterfactual_removal":"The bounded test can use the full local model and measured responses."},{"slug":"residual_reconstruction_test","disposition":"selected_load_bearing","contribution_type":"TEST_DESIGN","adaptation_or_rejection":"Reconstruct held-out measured responses from retained modes and inspect both residual magnitude and structure.","counterfactual_removal":"Omitted or nonlinear dynamics could remain invisible, eliminating the principal fidelity check."},{"slug":"singular_value_decomposition","disposition":"considered_rejected","contribution_type":"NONE","adaptation_or_rejection":"Singular directions quantify input-output amplification but do not by themselves provide the invariant dynamic modes and eigenvalue stability verdict targeted here.","counterfactual_removal":"The selected eigenspectrum workflow remains complete for the stated local operator; removal does not alter the test."},{"slug":"spectral_decomposition_report","disposition":"selected_supporting","contribution_type":"SAFETY_GUARDRAIL","adaptation_or_rejection":"Bind every actionable mode to physical coordinates, uncertainty, coupling warnings, and explicit limits on extrapolation.","counterfactual_removal":"The mathematics remains, but reviewers could mistake tentative local modes for globally valid causal facts, compromising authorization."},{"slug":"spectral_gap_monitor","disposition":"selected_supporting","contribution_type":"OPERATIONAL","adaptation_or_rejection":"During incremental testing, track mode separation, identity, frequency, and damping; alarm on gap or drift thresholds.","counterfactual_removal":"Mode veering or identity swaps could invalidate a fixed mitigation target between operating points without timely warning."}],"causal_chain":["Coupled aeroelastic states evolve through a locally valid transformation.","Eigendecomposition and bounded physical testing identify combined bending-torsion directions and their growth or damping rates.","Stability classification exposes a mode losing damping before any single coordinate exceeds its limit.","Consequence-weighted sensitivity identifies feasible changes that increase damping of that mode without unacceptable cross-effects.","Residual, coupling, gap, and drift checks determine whether the modal interpretation remains trustworthy.","Only validated changes advance to a separately authorized, incrementally expanded test envelope."],"baseline":"Ordinary practice for the target failure mode is coordinate-by-coordinate strain, displacement, and acceleration limits supplemented by static margins and selected frequency-response checks; these can miss a hazardous combination that is modest in every individual channel.","nearest_rival":"Full nonlinear time-domain aeroelastic simulation across the envelope, with candidate changes ranked directly by simulated worst-case response rather than by modal decomposition.","authority_safety":{"affected_parties":["test personnel and pilots","future aircraft occupants","maintenance and certification personnel","people beneath any flight-test area"],"decision_authority":"The accountable chief engineer and independent flight-test safety review board authorize interpretation and any envelope expansion; the test director retains immediate stop authority.","authorized_first_step":"On an instrumented ground article or subscale wind-tunnel model, excite only within predeclared load and amplitude limits at several below-boundary operating points; compare analytical and measured mode shapes, damping trends, sensitivities, and held-out reconstruction residuals.","excluded_actions":["crewed flight near the predicted flutter boundary","automatic deployment of an unvalidated controller","extrapolation beyond the declared linearization window","removal of existing structural or operational safety margins based only on the modal result"],"halt_rollback":"Halt excitation and return to the last cleared condition if vibration, load, residual, modal drift, or separation crosses its preregistered limit, or if mode identity becomes ambiguous; preserve existing margins and revise the model before retest."}},"negative_tests":{"strongest_counterevidence":"High-fidelity nonlinear simulations and bounded physical tests may show that coordinate-level limits already predict the earliest unsafe condition, while no stable, reproducible coupled mode loses damping first.","analogy_break":"The mapping breaks if large-amplitude nonlinearities, rapidly changing aerodynamics, strong non-normal transient growth, or configuration changes make local eigenmodes too short-lived or incomplete to guide action.","failure_condition":"The approach fails operationally if candidate modes cannot be repeatedly identified with adequate separation and physical traceability, or retained modes cannot reconstruct safety-relevant held-out responses within tolerance.","problem_falsifier":"Across the relevant bounded envelope, unsafe behavior is explained earlier and at least as reliably by one directly observable coordinate, with no repeatable coupled modal precursor or missed combination effect.","intervention_falsifier":"A preregistered design change predicted to improve hazardous-mode damping produces no improvement, worsens held-out response or cross-mode behavior, or loses its effect under repeated bounded tests.","risks":["Model error may assign false confidence to an apparently stable mode.","Closely spaced modes may swap identity and corrupt trend estimates.","Excitation or sensors may fail to reveal a real hazardous mode.","Optimization of one mode may worsen another or reduce static strength.","A local linear result may be extrapolated into nonlinear flight conditions."]},"null_rationale":null,"classification":{"candidate_kind":"MECHANISM_COMPOSITION","prior_art_status":"UNSEARCHED","evidence_maturity":"HYPOTHESIS"},"revision_change_log":{"revision_kind":"ORIGINAL","prior_problem_id":null,"prior_causal_lever_id":null,"problem_changed":false,"causal_lever_changed":false,"conceptual_changes":[],"operational_changes":[],"repairs_addressed":[]},"confidence":0.88,"generator_notes":"Closed-book structural inference from the supplied packet. Empirical applicability, thresholds, and intervention effects remain hypotheses pending the bounded test."}