SINTEF Ocean SIMO / RIFLEX Modeling (.inp, .sima, .sys, .hyd)

The @modelscript/sima package (languages/sima) provides native ingestion, analysis, verification, DAE simulation, and multi-domain projections for SINTEF Ocean / MARINTEK SIMO (Simulation of Marine Operations) and RIFLEX (Riser and Slender Marine Structural Dynamics) offshore engineering models and modern SIMA project archives.

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Supported File Specifications

Extension	Format	Key Structural Features
.inp / .sys	SIMO & RIFLEX Card Decks	Classical keyword cards: SYS, BODY, MASS, FAIRLEAD, LINE, SEGM, CRS, WAVE, WIND, CURR, DYNMOD
.sima	Modern SIMA XML Archive	Hierarchical task manifests (<simo:SimoTask>, <riflex:RiflexTask>, <sima:SlenderSystem>, <sima:Vessel>, <sima:MooringLine>)
.hyd / .out	Hydrodynamic Transfer Functions	1st-order Force RAO tables, frequency-dependent added mass $A(\omega )$, potential damping $B(\omega )$, and restoring matrices

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Architecture & Compilation Pipeline

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Pre-Flight Marine Linter Rules

15 rules9 error6 warning Run with msx lint

All severitieserrorwarning

Code	Rule	Severity	Message
M7001	negative-metacentric-height	error	Hydrostatic instability on vessel '<vessel>': negative <gmType> metacentric height (GM = <value> m < 0).
M7002	line-length-underflow	error	Mooring line '<line>' total length (<value> m) is less than water depth (<value> m), causing immediate vertical anchor snap load.
M7003	acoustic-courant-violation	error	Time step dt=<value>s exceeds Courant axial acoustic wave limit (<value>s) for segment '<seg>'.
M7004	unconnected-attachment-node	error	Mooring line '<line>' references unresolved fairlead attachment '<fairleadId>' not found on any vessel.
M7005	rao-frequency-extrapolation	warning	Environmental wave peak frequency (<value> rad/s) is outside hydrodynamic RAO table range [<value>, <value>] rad/s.
M7006	invalid-stiffness-hierarchy	error	Non-physical cross-sectional stiffness on segment '<seg>': <prop> (<val>) must be strictly positive.
M7007	unphysical-seabed-friction	warning	Unrealistic seabed friction coefficient (\u03BC = <value>): expected value between 0.0 and 2.0.
M7008	missing-hydrostatic-matrix	error	Vessel '<vessel>' has zero or missing hydrostatic restoring matrix C; floating body cannot equilibrate in heave/roll/pitch.
M7009	duplicate-line-identifier	error	Duplicate line identifier '<id>' declared in the slender system.
M7010	slack-compression-hazard	warning	Mooring line '<line>' has negligible pre-tension under severe sea state (Hs > 8m), risking compression slack-snap loading.
M7011	morison-drag-unspecified	warning	Segment '<seg>' in wave zone has zero Morison drag coefficient (Cd = 0); hydrodynamic damping will be neglected.
M7012	anchor-uplift-warning	warning	Catenary line '<line>' exhibits vertical uplift angle (<value>\xB0) at anchor; drag-embedment anchors will pull out.
M7013	mass-matrix-asymmetric	error	Vessel '<vessel>' structural mass matrix is asymmetric at index (<r>, <c>).
M7014	qtf-symmetry-violation	warning	Vessel '<vessel>' 2nd-order drift force QTF matrix violates conjugate symmetry.
M7015	exceeds-minimum-bend-radius	error	Line '<line>' minimum radius of curvature (<value> m) is below allowable MBR (<value> m).

Generated from languages/sima/src/lints/error-codes.ts. All languages →

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Regulatory Verification & In-WASM Solvers

1. DNV-OS-E301 & DNV-ST-0119 Compliance

Evaluates line tension safety factors against Minimum Breaking Load (MBL):

$$S_F=\frac{T_{\text{MBL}}}{T_{\text{max}}}\ge 1.67(\text{Intact Condition})$$$$S_F=\frac{T_{\text{MBL}}}{T_{\text{max}}}\ge 1.25(\text{Damaged / Single Line Broken})$$

2. Watch Circle & Touchdown Zone Verification

Computes vessel 6-DOF horizontal mean offset ellipse under coupled wind, wave drift, and current loads against allowable excursion limits (typically $\le 8\mathrm{\%}$ water depth for intact, $\le 12\mathrm{\%}$ for damaged). Checks fairlead declination angles ($\le {75}^{\circ }$) and ensures anchor uplift angle is exactly $0^{\circ }$ for drag-embedment anchors.

3. ASTM E1049 Rainflow Fatigue & Palmgren-Miner Cumulative Damage

Extracts stress/tension reversal cycles using the ASTM E1049-85 four-point rainflow algorithm and computes cumulative fatigue damage using Palmgren-Miner's rule ($D=\text{DFF}\cdot \sum \frac{n_i}{N_i}$) against DNV-OS-E301 S-N curves for studless chain, stud link, spiral strand wire, and polyester ropes.

4. Cummins 6-DOF Dynamics with Rational State-Space Radiation

Replaces the integro-differential retardation convolution integral with an $O(p)$ rational linear state-space system ($\dot{z}=A_{r}z+B_r\dot{x}$, $\mu =C_{r}z+D_r\dot{x}$), converting the frequency-dependent memory terms into continuous 1st-order ODEs lowered directly into @modelscript/runtime's DAEBuilder in linear WebAssembly memory.

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Headless CLI Operations (msx sima)

# Lint a SIMO / RIFLEX card deck or .sima XML archive
msx sima lint cases/OC4_Semi.inp

# Evaluate DNV-OS-E301 line tension safety factors against MBL
msx sima verify cases/OC4_Semi.inp --consequence-class=2

# Inspect floater watch circle, horizontal excursion, and touchdown clearances
msx sima offset cases/OC4_Semi.inp

# Inspect model summary (vessels, fairleads, lines, waves, wind)
msx sima summary cases/OC4_Semi.inp

# Synthesize acausal Modelica 6-DOF physical floater model
msx sima to-modelica cases/OC4_Semi.inp --out=OC4_Platform.mo

# Export multi-FMU SystemStructure.ssd co-simulation manifest
msx sima to-ssp cases/OC4_Semi.inp --out=SystemStructure.ssd

# Export formal SysML v2 architectural parts, ports, and DNV requirements
msx sima to-sysml2 cases/OC4_Semi.inp --out=OC4_Semi.sysml