{"abstention_reason":null,"arm":"SUBSTRATE_DIVERSE_P2","candidate_id":"discrete_continuous_model_selection__engineering_design__SUBSTRATE_DIVERSE_P2","cell_id":"discrete_continuous_model_selection__engineering_design","decision":"PROPOSAL","experiment_id":"eoa_inverse_innovation_exp13_second_slot_policy60_20260806","proposal":{"actors":["Composite pressure-vessel test engineer","Structural materials engineer","Optical instrumentation technician","Nondestructive-evaluation specialist","Pressure-test safety officer"],"affected_objective":"Locate strain concentrations and incipient buckling patterns during qualification of thin-walled composite pressure vessels without inferring an unobserved surface field from sparse point gauges.","arm":"SUBSTRATE_DIVERSE_P2","authority_safety":{"authorized_first_step":"Apply and evaluate the coating only on a sacrificial subscale composite shell or witness panel inside its preapproved elastic pressure-test envelope; treat all observations as supplementary and non-qualifying.","decision_authority":"The designated pressure-test safety officer controls test execution and limits, while the responsible structural test engineer retains qualification and design-change authority under existing procedures.","excluded_actions":["Exceed an approved pressure, load rate, or cycle count","Remove required strain gauges, leak checks, proof tests, or nondestructive examinations","Use the optical field alone to accept a pressure vessel or increase its rating","Apply an unqualified coating to a flight, medical, or operational pressure vessel","Continue loading after an existing stop criterion is reached"],"halt_rollback":"Stop the trial if the coating debonds, cracks independently of the substrate, obscures leak or damage inspection, produces temperature drift comparable to the load response, or requires loading beyond the approved envelope. Remove the coating where permitted and retain the established gauge, proof-test, and nondestructive-evaluation process."},"baseline":"Bond strain gauges at selected points, record them at several scheduled pressure holds, and use finite-element interpolation or engineering judgment to infer the shell response between gauges; separately classify the proof test as pass or fail.","candidate_id":"discrete_continuous_model_selection__engineering_design__SUBSTRATE_DIVERSE_P2","causal_chain":["Internal pressure produces a spatially distributed shell response: membrane strain usually varies gradually, while thickness changes, fiber waviness, local stiffness loss, debonding, or buckling can create steep gradients or abrupt boundaries.","Sparse gauges discretize that surface into a few instrumented points, so a concentration between gauges can remain invisible.","Smooth interpolation between those points can then manufacture a benign field across a real localization or damage boundary.","A compliant birefringent coating physically converts local principal-strain difference into spatially varying optical retardation under polarized illumination.","The visible fringe field supplies a continuous two-dimensional representation across optically coupled regions without requiring each location to be a separate electrical sensor.","Explicit boundary rules prohibit interpolation across coating cracks, debonded areas, occlusions, or sharp fringe discontinuities; those regions remain unresolved and require conventional inspection.","Calibration panels and bounded pressure cycles test whether the chosen spatial and load-sampling resolution exposes known gradients without fabricating discontinuities.","If the physical field repeatedly reveals decision-relevant localization missed by the point representation, engineers gain evidence for gauge placement, reinforcement, or further inspection; otherwise the baseline remains controlling."],"cell_id":"discrete_continuous_model_selection__engineering_design","consequence":"A dangerous strain concentration or buckling lobe can fall between gauges, while smooth interpolation can erase a real boundary; conversely, treating every gauge reading as a separate response category can exaggerate harmless point-to-point variation and encourage unnecessary reinforcement.","diversity_from_prior_proposals":"Unlike sealed P1, which integrates temporal fatigue exposure and load events for crane-rope maintenance, this opportunity addresses spatial strain localization during composite-shell qualification. It uses a material-optical field transducer, selects continuous spatial representation rather than a temporal hybrid ledger, and reaches design evidence through stress-induced birefringence rather than rope-history reconstruction. No other proposals or experiments were inspected.","experiment_id":"eoa_inverse_innovation_exp13_second_slot_policy60_20260806","intervention":"Apply a thin, compliant photoelastic coating to the exterior of a sacrificial composite shell or representative panel. Illuminate it through crossed polarizers during a continuously ramped, bounded pressure test so stress-induced birefringence produces a directly visible surface field of optical retardation. Calibrate fringe response and temperature sensitivity on a witness laminate with colocated conventional gauges. Select optical spatial resolution and observation cadence from the smallest localization and fastest load change relevant to the test decision. Treat smoothly connected fringes as a continuous field only within verified coating-coupled regions; mark coating cracks, debonding, occlusion, and sharp fringe breaks as non-interpolable boundaries requiring conventional inspection. Digital capture may archive or measure the field, but the material coating, polarized illumination, and visible retardation pattern provide the essential measurement.","mechanism_mapping":[{"counterfactual_removal":"Without the continuous-field representation, the shell returns to isolated point readings whose intervening gradients must be assumed rather than observed.","mechanism_slug":"continuous_process_model","role":"Represents the shell's spatial response as a physically observed retardation gradient across coupled coating regions."},{"counterfactual_removal":"Without sustained observation through the load ramp, localization that appears and relaxes between scheduled pressure holds can be missed.","mechanism_slug":"continuous_monitoring","role":"Observes evolution of the optical field across the bounded pressure ramp rather than only at discrete hold points."},{"counterfactual_removal":"Without a resolution choice tied to expected localization width and loading rate, optical blur or slow observation can smooth away the feature the test is intended to detect.","mechanism_slug":"sampling_interval_choice","role":"Sets spatial optical resolution and load-domain observation cadence to match decision-relevant gradients."},{"counterfactual_removal":"Without the audit, coating artifacts, optical blur, and real substrate discontinuities could be confused, leaving the apparent field unjustified.","mechanism_slug":"transition_resolution_audit","role":"Checks field continuity and sharp boundaries against seeded geometric features, colocated gauges, repeated cycles, coating-quality observations, and post-test nondestructive examination."}],"nearest_rivals":["A denser strain-gauge array improves coverage but still samples discrete points and may miss localization between them.","Digital image correlation estimates a full displacement field but depends essentially on image-correlation algorithms, whereas the proposed coating creates a visible material-optical response before computation.","Finite-element refinement predicts a finer field but does not physically observe manufacturing-specific waviness, debonding, or local stiffness error.","Acoustic-emission monitoring detects discrete energy-release events but does not represent the continuous spatial strain gradient that precedes localization.","A pass/fail proof-pressure hold confirms survival at a prescribed load but does not show where the shell approached a local instability."],"negative_tests":{"intervention_falsifier":"Reject the intervention if blinded reviewers cannot reproducibly locate predeclared stiffness transitions or seeded benign localization features better than the baseline gauges, if apparent boundaries fail to repeat across bounded cycles, or if coating and temperature artifacts are as large as the load-induced field.","problem_falsifier":"The inferred problem is weakened if baseline gauges and required inspections already locate every decision-relevant concentration, the measured field is smooth at the needed scale, and qualification or reinforcement decisions remain invariant when the continuous field is revealed.","risks":["Coating stiffness or thickness may perturb the surface response it is intended to measure.","Imperfect strain transfer, coating cracks, or debonding can create false discontinuities.","Temperature-dependent birefringence can be mistaken for load response.","Optical fringes report principal-strain difference rather than a complete strain tensor and may be overinterpreted.","Curvature, glare, occlusion, and polarizer alignment can reduce spatial resolution.","The added field may encourage false precision or improper substitution for required gauges and nondestructive examination.","Pressure testing retains stored-energy, rupture, and leak hazards governed by the existing test plan."],"strongest_counterevidence":"The coating may transfer strain too unreliably on curved composite surfaces to improve decisions, while validated finite-element analysis, existing gauges, and post-test nondestructive examination may already bound every consequential localization."},"next_evidence_step":"On one sacrificial subscale cylindrical composite panel containing predeclared thickness tapers and a benign embedded release-film feature, install the coating and the baseline gauge layout. Within an approved elastic pressure envelope, conduct three identical ramps while recording pressure, temperature, gauge readings, coating condition, and unprocessed polarized fringe images. Before loading, specify spatial resolution, observation cadence, continuity regions, invalid-boundary rules, and success criteria. Have two blinded structural reviewers mark localization zones independently from the baseline record and from the optical field, then compare both with known feature locations and post-test nondestructive examination. Do not use the trial to qualify an operational vessel.","observable_state":"Pressure and temperature traces, point-gauge readings, raw polarized fringe images or direct visual plates, coating-thickness and adhesion checks, shell geometry, known witness-panel features, load-cycle repeatability, and post-test ultrasonic or thermographic inspection results are available for comparison.","prior_art_status":"UNSEARCHED","problem":"Composite pressure-shell qualification commonly represents surface response through discrete strain gauges and scheduled pressure holds. That representation can miss continuous spatial gradients and localized buckling between gauges, while smooth interpolation across the unmeasured surface can erase abrupt strain-transfer or damage boundaries. Adding arbitrary gauge points also creates a costly point-by-point discretization without establishing the resolution needed for the design decision.","proposal_index":2,"remaining_contrastive_claim":"Within a bounded composite-shell test, a material photoelastic coating can physically reveal a continuous spatial retardation field and preserve non-interpolable breaks in a way that sparse gauges, a smoother finite-element field, acoustic event detection, or proof-pressure survival cannot provide alone.","revision_record":{"claim_changes":["Initial P2 version; no prior P2 claim was revised."],"conceptual_changes":["Uses continuous spatial-field selection rather than P1's hybrid temporal event-and-accumulation representation.","Makes a material-optical transducer, not a computational model, the essential intervention."],"evidence_changes":["No efficacy evidence is claimed; a bounded sacrificial-panel comparison with repeatability and blinded localization tests is specified."],"operational_changes":["Restricts initial use to a non-qualifying subscale test inside an existing elastic envelope and retains all mandated instrumentation and inspections."],"parent_version":null,"progress_targets_addressed":["Materially independent problem, intervention, and causal path","Explicit false-discreteness and false-smoothness costs","Measurement resolution aligned with spatial gradients and load cadence","Continuity and non-interpolation boundary rules","Physical-substrate counterfactual audit","Falsifiers, authority limits, halt conditions, and bounded evidence step"]},"schema_version":1,"structural_mapping":[{"archetype_element":"Decision Need","domain_realization":"Determine whether shell localization warrants changed gauge placement, reinforcement, geometry, or additional inspection before qualification."},{"archetype_element":"Process Change Signature","domain_realization":"Pressure-induced strain forms a spatial gradient across the shell, with possible steep localization or abrupt breaks at defects, stiffness transitions, coating failures, or buckling boundaries."},{"archetype_element":"Cost of False Smoothness","domain_realization":"Interpolating smoothly between gauges can erase a localized buckle, debond boundary, or sharp strain-transfer change."},{"archetype_element":"Cost of False Discreteness","domain_realization":"Treating a continuous shell as isolated gauge locations can miss gradients between points and turn minor point variation into artificial design categories."},{"archetype_element":"Granularity Choice","domain_realization":"Use a continuous optical field over verified coupled regions, with spatial resolution tied to the smallest decision-relevant localization."},{"archetype_element":"Step Boundary","domain_realization":"Coating cracks, loss of adhesion, occlusion, sharp fringe breaks, and known geometric interfaces delimit regions across which field values may not be interpolated."},{"archetype_element":"Continuity Assumption","domain_realization":"Optical retardation is treated as spatially continuous only where coating adhesion, thickness, temperature compensation, illumination, and fringe connectivity pass predeclared checks."},{"archetype_element":"Measurement Resolution","domain_realization":"Polarizer optics, viewing geometry, coating calibration, image or visual sampling, and pressure-ramp cadence must resolve the expected localization width and load-domain onset."},{"archetype_element":"Transition Validation","domain_realization":"Observed gradients and breaks are compared across repeated cycles with known panel features, point gauges, coating inspection, and post-test nondestructive examination."},{"archetype_element":"Approximation Error Check","domain_realization":"Reviewers compare localization and design-review conclusions from sparse point measurements with those from the continuous optical field, including false boundaries and unresolved regions."},{"archetype_element":"Scale Shift Review","domain_realization":"Results from the subscale panel cannot be transferred to a full curved vessel until coating strain transfer, optical access, curvature, and localization scale are separately validated."}],"substrate_contract":{"counterfactual_independence":"If software, automated image processing, databases, models, alerts, and digital control are removed, the bonded birefringent coating under crossed polarizers still converts the shell's mechanical strain distribution into a visible spatial fringe field that can be compared with a physical calibration reference. Those wrappers improve recording and quantification but do not create the essential measurement.","forbidden_channel_audit":"Governance limits only who may load or qualify the article; training supports safe observation; optional software may archive images or extract fringe values. None of these supplies stress-induced birefringence, transfers shell strain into the coating, illuminates the field, or produces the visible retardation pattern. The essential causal channel is mechanical strain transfer followed by material-optical measurement.","primary_allowed_process":"MEASUREMENT_INSTRUMENTATION"},"title":"Photoelastic Continuous-Field Witness for Composite Shell Qualification","version":0},"schema_version":1}