{"abstention_reason":null,"arm":"SUBSTRATE_DIVERSE_P2","candidate_id":"ensemble_and_population_level_equilibrium_versus_individual_level_heterogeneity__engineering_design__SUBSTRATE_DIVERSE_P2","cell_id":"ensemble_and_population_level_equilibrium_versus_individual_level_heterogeneity__engineering_design","decision":"PROPOSAL","experiment_id":"eoa_inverse_innovation_exp13_second_slot_policy60_20260806","proposal":{"actors":["Structural connection designer","Mechanical test engineer","Fastener specialist","Reliability engineer","Maintenance engineer","Independent structural-safety reviewer","Bolts treated as ensemble members"],"affected_objective":"Preserve the global stiffness and alignment of a large structural flange while preventing local joint opening, fretting, and bolt-fatigue risk caused by heterogeneous retained preload.","arm":"SUBSTRATE_DIVERSE_P2","authority_safety":{"authorized_first_step":"The connection test lead may inspect and instrument a de-energized, unloaded representative flange coupon, record each bolt's mechanical indicator displacement and ultrasonic elongation, and run one proof-load cycle within the coupon's approved limits without changing fasteners or tightening torques.","decision_authority":"The structural connection review board retains authority to define actionable preload bands, approve disc-spring cartridge dimensions, authorize any retensioning or field retrofit, and release the connection design.","excluded_actions":["No loosening, removal, retensioning, or washer substitution on an in-service load-bearing connection under this proposal's measurement-only first step.","No entry beneath or inside a structure supported by the connection unless existing lockout, shoring, access, and inspection procedures authorize it.","No inference of bolt force from tightening torque alone where friction uncertainty has not been bounded.","No reduction of bolt count, bolt grade, proof-load factor, fatigue margin, or existing inspection requirement.","No reuse of yielded, cracked, corroded, galled, or otherwise nonconforming fasteners.","No field retrofit based solely on an average preload or on a single anomalous bolt reading."],"halt_rollback":"Stop the coupon test upon unexpected joint opening, bolt-yield indication, crack initiation, fixture motion, sensor disagreement beyond the predeclared tolerance, or any approved rig limit. Unload through the established sequence, restore the coupon to its documented baseline assembly, quarantine questionable hardware and data, and require structural-safety review before another cycle."},"baseline":"Large circular or segmented flanges are accepted using stable global alignment, ring-average compression or stiffness, proof-load response, and an installation procedure intended to produce the specified mean bolt preload. Individual retained preloads may vary because of tightening sequence, friction, flange waviness, local grip stiffness, and embedment relaxation, but their distribution and circumferential clustering are not necessarily acceptance criteria.","candidate_id":"ensemble_and_population_level_equilibrium_versus_individual_level_heterogeneity__engineering_design__SUBSTRATE_DIVERSE_P2","causal_chain":["A multi-bolt flange transfers axial force and bending moment through the combined preload and stiffness of its fastener ensemble and contacting flange faces.","Friction scatter, flange waviness, grip-length differences, tightening sequence, and local embedment give individual bolts different initial forces and different preload losses.","The sum and moment-weighted distribution of bolt forces can still produce stable global alignment, ring-average compression, and proof-load stiffness.","Those macro indicators compress away bolt identity and circumferential clustering, allowing high-force and low-force bolts to compensate in the aggregate.","Underloaded neighboring bolts can permit local interface opening and fretting, while overloaded bolts carry larger cyclic stress ranges, even though the connection-level response remains acceptable.","Mechanical load-indicating features expose each bolt's retained preload, distinguishing isolated uncertainty from persistent low- or high-preload arcs beneath the valid global state.","A calibrated disc-spring washer cartridge placed in series with an actionable bolt increases elastic travel and reduces the bolt force lost to small local settlement or grip-stiffness differences.","Reviewer-approved retensioning to a cartridge-displacement band corrects consequential tails while leaving harmless member variation intact, and a repeated proof cycle verifies both global stiffness and the bolt-force distribution."],"cell_id":"ensemble_and_population_level_equilibrium_versus_individual_level_heterogeneity__engineering_design","consequence":"A flange may retain acceptable global stiffness and alignment while a circumferential subset of bolts loses clamping force and another subset becomes cyclically overloaded, creating local gapping, fretting, leakage where applicable, or fatigue damage that the stable connection-level indicator does not reveal.","diversity_from_prior_proposals":"This opportunity differs materially from sealed P1 in affected problem, intervention, and causal path: it addresses mechanical preload dispersion and local flange contact beneath stable structural response, uses passive series compliance and direct bolt-force indication, and acts through bolt elongation, settlement sensitivity, and interface clamping rather than battery heat generation, coolant distribution, temperature aggregation, or thermal balancing.","experiment_id":"eoa_inverse_innovation_exp13_second_slot_policy60_20260806","intervention":"Create a heterogeneity-aware flange design and acceptance layer based on physical bolt-by-bolt indication and passive compliance. Define all bolts in one flange as the ensemble and the stabilized portion of approved proof-load cycles as the equilibrium window. Retain the existing global stiffness, alignment, and ring-compression criteria, but pair them with each bolt's calibrated mechanical indicator displacement, corroborative elongation measurements on the test article, circumferential quantiles, persistence across cycles, and a map of contiguous outliers. Predeclare uncertainty-aware high- and low-preload bands. For a reviewer-approved design trial, replace the conventional washer assembly at actionable positions with a qualified disc-spring cartridge whose force-travel curve adds sufficient series compliance to retain clamp force through expected embedment and grip variation; retension using the cartridge's directly observable travel band. Repeat the proof cycle and accept the design only if local opening and actionable tails decrease without violating global stiffness, alignment, bolt proof strength, bearing-pressure, fatigue, or clearance limits.","mechanism_mapping":[{"counterfactual_removal":"Without simultaneous macro and member-level presentation, acceptable global stiffness can again obscure compensating high- and low-preload bolts.","mechanism_slug":"distributional_dashboard","role":"Pairs the valid connection-level proof response with bolt-force quantiles, indicator travel, persistence, and circumferential position."},{"counterfactual_removal":"Without the crosswalk, reviewers cannot see how individual axial forces and their lever arms combine into total clamp force and moment resistance or which local contact information aggregation discards.","mechanism_slug":"micro_macro_crosswalk","role":"States the force-sum and moment-weighted translation from bolt preloads to flange-level equilibrium indicators."},{"counterfactual_removal":"Without decomposition, repeatability error, friction scatter, position-dependent flange stiffness, tightening-sequence effects, and cycle-dependent settlement remain conflated.","mechanism_slug":"variance_decomposition_table","role":"Separates measurement uncertainty and within-bolt cycle variation from between-bolt and circumferentially clustered mechanical variation."},{"counterfactual_removal":"Without a persistence and adjacency rule, one uncertain reading may drive unnecessary work while a recurring low-preload arc remains hidden by the stable global response.","mechanism_slug":"subgroup_excursion_alert","role":"Flags predeclared contiguous flange sectors or persistent individual tails for engineering review."},{"counterfactual_removal":"Without a repeated proof cycle after the passive-compliance trial, the cartridge could merely shift force to other bolts or preserve preload at the cost of unacceptable joint flexibility.","mechanism_slug":"equilibrium_stress_test","role":"Tests whether the mechanical intervention improves retained-preload tails and local contact while preserving the connection-level equilibrium."}],"nearest_rivals":["A uniform retorque program that applies the same torque to every bolt without measuring retained force or distinguishing harmless spread from actionable tails.","A flange-stiffening redesign intended to eliminate all deformation, rather than preserve a valid global response while correcting consequential bolt-level heterogeneity.","An aggregation-bias project that rejects the global stiffness or compression metric as invalid; here that metric may remain valid for connection-level behavior but incomplete for member-level safety.","An equilibrium-restoration intervention for a flange whose global alignment or stiffness has already become unstable; this proposal concerns hidden bolt variation while those macro indicators remain stable.","A fastener-quality inspection that attributes all preload dispersion to defective bolts without testing position, settlement, friction, and grip-stiffness effects."],"negative_tests":{"intervention_falsifier":"The mechanical intervention is falsified if qualified disc-spring cartridges and displacement-based retensioning do not reduce persistent actionable preload tails or local opening relative to conventional washers under matched assembly and proof cycles, or if they introduce unacceptable joint flexibility, bearing stress, relaxation, fatigue, or clearance effects.","problem_falsifier":"The problem is falsified if bolt-level measurements across repeated approved cycles show no consequential retained-preload spread beyond characterized uncertainty, if outliers do not persist or cluster, or if existing acceptance already enforces bolt-by-bolt retained-force and local-contact criteria. It is also falsified for this archetype if the flange-level indicator is itself unstable, making equilibrium restoration the primary problem.","risks":["Ultrasonic elongation can be biased by bolt geometry, temperature, coupling, and reference-length uncertainty.","Mechanical indicator travel may be misread if the cartridge seats unevenly or its force-travel calibration is not traceable.","Added compliance can increase joint motion or alter fatigue behavior if incorrectly sized.","Changing one bolt position can redistribute load to adjacent bolts and flange sectors.","Retensioning can overload bolts or crush bearing surfaces if performed without an approved sequence and calibrated tooling.","Cartridges may relax, corrode, fret, or lose travel clearance over the service environment.","Post hoc selection of circumferential sectors can manufacture apparent clusters; partitions and thresholds must be frozen before evaluation."],"strongest_counterevidence":"Existing qualified installation controls may already keep every bolt within a safe retained-preload band, while measured spread may be dominated by instrument uncertainty and may have no detectable relationship to local opening or cyclic stress; either result would substantially weaken the opportunity."},"next_evidence_step":"On one de-energized representative flange coupon assembled with production-intent bolts and surfaces, freeze ensemble membership, proof-cycle window, force-conversion calibration, circumferential sectors, uncertainty bounds, and excursion criteria before reviewing results. Record mechanical indicator travel and corroborative ultrasonic elongation for every bolt before and after one approved proof cycle, together with global stiffness, alignment, and local interface-opening gauges. The bounded decision is only whether evidence warrants a separately approved cartridge-sizing and repeat-test trial.","observable_state":"During repeated approved proof loading, the flange's global load-displacement slope, alignment, and ring-average compression remain within stable bands, while individual retained bolt forces may occupy persistent upper and lower tails or form contiguous circumferential clusters. Observable inputs include bolt identity and position, indicator displacement, calibrated force-travel curve, ultrasonic elongation where used, flange-face gap gauges, applied load, global displacement, tightening sequence, surface condition, temperature, and measurement uncertainty.","prior_art_status":"UNSEARCHED","problem":"A multi-bolt structural flange is declared acceptable because its global alignment, average compression, and proof-load stiffness are stable. That valid connection-level result is treated as though every bolt retains comparable preload. In reality, friction, flange waviness, grip stiffness, tightening sequence, and embedment can produce compensating high- and low-preload bolts. Persistent low-preload arcs can permit local opening and fretting, while high-preload members acquire greater cyclic stress, without invalidating the stable aggregate response.","proposal_index":2,"remaining_contrastive_claim":"A valid, stable flange-level stiffness and alignment result can remain suitable for assessing the whole connection while being insufficient to establish safe retained preload for each bolt; persistent bolt-level tails or contiguous outlier arcs should therefore trigger a reviewer-gated passive-compliance trial rather than automatic rejection of the macro metric or indiscriminate retorquing of the entire flange.","revision_record":{"claim_changes":[],"conceptual_changes":[],"evidence_changes":[],"operational_changes":[],"parent_version":null,"progress_targets_addressed":["Defined a nonthermal engineering ensemble, a valid structural macro-equilibrium indicator, bolt-level heterogeneity, and the force-and-moment aggregation rule.","Specified a passive mechanical intervention whose effect arises from calibrated series compliance and direct physical displacement indication.","Separated harmless preload variation from persistent member or circumferential-tail conditions requiring action.","Added bounded measurement-only entry, retained structural authority, falsifiers, counterevidence, and explicit retrofit safeguards.","Established material independence from sealed P1 across problem, intervention, and causal pathway."]},"schema_version":1,"structural_mapping":[{"archetype_element":"Ensemble Frame","domain_realization":"Every bolt in one defined production-intent flange assembly under a specified tightening sequence, surface condition, temperature range, and approved proof-load protocol."},{"archetype_element":"Macro Equilibrium Indicator","domain_realization":"Stable connection-level load-displacement stiffness, alignment, and ring-average compression over the stabilized proof-cycle window."},{"archetype_element":"Microstate Variability Profile","domain_realization":"Each bolt's retained force or calibrated indicator travel, bolt-force quantiles, cycle-to-cycle persistence, and circumferential clustering, paired with local flange-gap observations."},{"archetype_element":"Aggregation Translation Rule","domain_realization":"Individual axial bolt forces sum to total clamping force and combine with their locations through moment arms to resist external moment; this translation loses bolt identity, adjacent low-force clustering, and local interface-contact state."},{"archetype_element":"Level-of-Analysis Boundary","domain_realization":"Global stiffness and alignment support a claim about the assembled connection, not uniform preload in every bolt. Conversely, one anomalous bolt reading does not by itself disprove stable connection-level behavior."},{"archetype_element":"Heterogeneity Relevance Test","domain_realization":"Compare bolt-force magnitude, persistence, adjacency, measurement uncertainty, local opening, proof-strength margin, and fatigue implications before classifying variation as benign or actionable."},{"archetype_element":"Subgroup and Locality Map","domain_realization":"Map bolts by circumferential sector, flange segment, proximity to joints or penetrations, load-axis position, grip length, and tightening-sequence position."},{"archetype_element":"Multi-Level Feedback Design","domain_realization":"Continue monitoring global proof response while using physical bolt indicators and local gap gauges to gate reviewer-approved cartridge sizing and targeted retensioning."},{"archetype_element":"Representative Case Guardrail","domain_realization":"Neither one nominal bolt nor the most extreme reading substitutes for the full synchronized bolt ensemble; missing, unreadable, or uncalibrated indicators are reported explicitly."},{"archetype_element":"Equity or Risk Threshold","domain_realization":"Predeclared uncertainty-aware retained-force, proof-strength, local-opening, persistence, and adjacency limits distinguish tolerable assembly variation from fatigue or loss-of-clamp risk."}],"substrate_contract":{"counterfactual_independence":"If all software, databases, automated analytics, digital control, training programs, incentives, and organizational routing are removed, calibrated mechanical indicator travel still reveals member-level preload, and the disc-spring cartridge still supplies physical series compliance that reduces clamp-force sensitivity to settlement. Manual gauges, paper records, and existing structural review are sufficient to demonstrate the essential effect.","forbidden_channel_audit":"Governance only gates safety-critical action; it does not generate or redistribute preload. Calculations may size and interpret the hardware but do not supply its operative effect. No algorithm, model, database, information-routing system, training program, incentive, or controller is required for the cartridge to deform elastically, retain clamp force, or expose its travel mechanically.","primary_allowed_process":"HYBRID_OTHER_ALLOWED_PRIMARY"},"title":"Bolt-Level Preload Indication and Passive Compliance for Stable Structural Flanges","version":0},"schema_version":1}