ComPACT Software | Osimulon

ComPACT composites compaction modeling multi-physics framework header

Composite compaction Inventory-based Abaqus VUEL MRT-LBM-DEM solver Multiphase process physics Validation-ready cases

Software framework

From process inputs to validated manufacturing predictions.

ComPACT connects compaction pressure, laminate architecture, resin transport, thermal history, cure behavior, and defect evolution in one simulation-focused workflow for composite manufacturing.

Define process

Set pressure, temperature, vacuum, laminate geometry, material laws, and boundary conditions.

Run solver level

Use macro VUEL models for part behavior or micro MRT-LBM-DEM models for local flow mechanisms.

Extract risk

Read thickness change, porosity, resin bleed, void motion, cure state, deformation, and defect geometry.

Validate cases

Compare outputs with microscopy, flow visualization, residual-shape testing, and benchmark data.

Solver architecture

Two solver levels for one process workflow.

The page separates the part-scale macro solver from the local micro solver so each case can show the right physics at the right length scale.

Macro solver

ComPACT Abaqus VUEL

Hex8 Abaqus/Explicit user element for thermo-chemo-poro-mechanical composite-process modeling at laminate and part scale.

Fields: Displacement, temperature, resin pressure, saturation, and cure
Use: Compaction, resin-air transport, cure shrinkage, porosity, and residual deformation

Uses VU1 prepreg, VU2 transport connectors, and VU3 moving gap cavities.
Tracks finite resin and air inventories and returns cavity pressure to bounding plies.
Supports coupled heat, pressure, saturation, cure, and deformation response.

Micro solver

micro_ComPact

MRT-LBM-DEM solver for local resin flow, particle motion, trapped air, immersed moving boundaries, and benchmark validation.

Physics: Flow, particles, contact, cure, and temperature
Use: Local mechanisms, defect evolution, void interaction, and validation-ready visual outputs

D2Q9 MRT lattice-Boltzmann flow with DEM particle coupling.
Captures trapped-air, void, and resin interaction in process features.
Validated with sedimentation and particle-interaction benchmark cases.

Capabilities

A structured toolkit for manufacturing physics.

These modules frame the page around the problems ComPACT is built to explain: compaction, resin transport, defects, cure, validation, and solver coupling.

Compaction Mechanics

Track thickness change, ply nesting, pressure transfer, and laminate consolidation.

Resin and Porosity

Connect local deformation, resin transport, void evolution, and process history.

Multiphase Flow

Model resin, voids, trapped air, and interface motion during pressure-driven processing.

Multi-physics Coupling

Prepare coupled simulation paths for mechanics, flow, temperature, and cure effects.

Validation Workflow

Organize model outputs for comparison with microscopy, DIC, micro-CT, and tests.

Solver Core

Use the micro_ComPact MRT-LBM-DEM solver for coupled resin flow, particle motion, and compaction boundary conditions.

Residual Shape

Compare modeled and measured spring-in, curvature, and deflection after thermal processing.

Defect Reconstruction

Translate microscopy observations into simulation-ready ply paths, resin pockets, and local defect geometry.

Frontal Polymerization

Connect cure kinetics, temperature, viscosity growth, and gelation into process-scale front simulations.

Benchmark Validation

Compare particle-fluid simulations against published sedimentation and interaction benchmarks.

Macro-Scale VUEL

Run Abaqus/Explicit Hex8 user-element models for coupled compaction, heat, pressure, saturation, and cure.

Moving Gap Cavities

Preserve finite resin and air ownership inside closing tow gaps while feeding cavity pressure back to adjacent plies.

Latest manuscript results

From calibrated tow response to manufacturing-induced gap morphology.

The new three-dimensional inventory-based VUEL formulation couples deforming prepreg to moving tow-gap control volumes. Three studies test directional bleed-out, finite cavity storage, pressure feedback, resin retention, air removal, and localized fiber waviness.

Single-tow FVF 0.6066

Predicted at the largest measured strain, versus 0.6088 experimentally.

Bleed-out error 9.3% / 4.0%

Maximum pointwise error for longitudinal and transverse discharge.

Pocket length 0.86%

Difference between the isolated-gap prediction and published micrograph.

Resin ledger 0.644%

Maximum donor-plus-gap mass-balance error in the isolated-gap study.

Tool-side retention +31%

Mean opening and resin mass retained by G4-G5 relative to G1-G3.

Laminate mean FVF 0.631

Endpoint value for the seven-ply staggered-gap laminate.

Study 01 / Calibration

Single-tow compaction and anisotropic resin bleed-out

One coupled IM7/8552 calculation reproduces the nonlinear rise in fiber volume fraction and the much stronger longitudinal drainage observed over a 90-minute pressure-and-temperature history.

-0.36%FVF error at the largest measured thickness strain.
0.435 mg/mm²Predicted final longitudinal bleed-out versus 0.398 measured.
0.0205 mg/mm²Predicted final transverse bleed-out versus 0.0198 measured.

Single-tow longitudinal and transverse resin bleed-out paths with ComPACT histories compared against experiments — **Directional bleed-out.** The calibrated histories capture the two-stage longitudinal response and transverse plateau within a 10% tolerance.

Single-tow fiber volume fraction response and initial versus 90-minute ComPACT contour fields — **Compaction response.** The global FVF curve follows experiment while the field reveals outlet-driven spatial variation hidden by the average.

The transport parameters were selected using these measurements, so this study is a calibration benchmark rather than an independent validation.

Study 02 / Mechanistic verification

Three-ply isolated tow-gap closure, filling, and cure

A reduced [0/90/0] laminate isolates the two-way cavity mechanism: ply motion changes gap volume, gas compression and resin filling set cavity pressure, and that pressure loads the bounding plies.

0.150 to 0.03595 mmReduction in mean gap opening over the 210-minute history.
0.818 mmPredicted pocket length versus 0.811 mm in the published micrograph.
99.51%Removal of the modeled initial cavity-air inventory.

Three-ply isolated tow-gap architecture and comparison of cured experimental and ComPACT pocket morphology — **Cured pocket morphology.** ComPACT reproduces the tapered pocket envelope and adjacent-ply rotation, with 0.86% pocket-length error.

ComPACT history of gap resin mass, maximum pressure, degree of cure, and temperature — **Cavity-state history.** Heating activates the principal filling event before cure-driven viscosity growth arrests further transfer.

Study 03 / Staggered laminate

Five tow gaps evolving through rolling, pressure, heating, and cure

A seven-ply [0/90/0/90/0/90/0] laminate links through-thickness gap position and bridging support to residual opening, retained resin, compaction heterogeneity, and out-of-plane fiber rotation.

0.0142-0.0195 mmFinal mean opening across gaps G1-G5.
2.21-3.04 mgFinal resin mass retained by each physical gap.
99.86-99.90%Final net removal of the modeled cavity-air inventory.

Initial and compacted staggered-gap laminate with ComPACT residual volumes compared against polished micrographs — **Bridging and residual pockets.** The numerical morphology localizes tapered residual volumes where polished sections show analogous resin-rich regions.

ComPACT out-of-plane fiber-angle field compared with a micro-CT-derived angle map — **Localized fiber rotation.** Simulation and micro-CT show elevated angles at corresponding gap tips and ply-transition regions on a common 0-10 degree scale.

Final opening, retained resin, and resin accumulation histories for staggered gaps G1 through G5 — **Gap depth controls retention.** Tool-side G4-G5 retain approximately 31% more mean opening and resin mass than G1-G3.

Modeled net air removal histories for staggered gaps G1 through G5 — **Modeled air inventory.** Early roller-driven expulsion and re-entry give way to near-complete net removal as resin fills the cavities.

Final ComPACT fiber volume fraction field and enlarged sections through aligned gap columns — **Heterogeneous densification.** Supported tow segments compact more strongly than compliant regions adjacent to the moving cavities.

Ply-averaged permanent compaction and fiber volume fraction histories predicted by ComPACT — **Process-stage response.** Rolling, pressure buildup, heating, and the final temperature ramp leave distinct increments in every ply.

Additional demonstrations

The broader toolkit extends beyond the manuscript benchmarks.

These cases highlight additional manufacturing challenges, modeled physics, and outputs that can guide process design.

01 Bleed-out 02 Multiphase flow 03 Bilamina 04 Defect reconstruction 05 Frontal polymerization 06 Benchmarks

Case 01

Transverse resin bleed-out during heated compaction

Problem: Model transverse resin bleed-out from a compacted composite specimen under pressure and elevated temperature.
Setup: Vacuum pressure boundary conditions, 110°C thermal loading, constrained lower surface, and a porous representative domain.
Solver: MRT-LBM-DEM simulation from the micro_ComPact codebase, with D2Q9 MRT lattice-Boltzmann flow, DEM contact motion, and immersed moving-boundary particle coupling.
Outputs: Transverse bleed-out area, resin mass bleed-out over time, and comparison between experimental data and MRT-LBM-DEM prediction.
Why ComPACT: ComPACT links the applied compaction and thermal boundary conditions to resin transport, then turns the simulated flow response into quantities that can be compared directly with measured bleed-out.

Boundary conditions for transverse resin bleed-out compaction model — **Model boundary conditions.** The case starts by defining the compaction pressure, vacuum pressure, thermal state, and displacement constraint. ComPACT uses this setup to translate the laboratory compaction environment into a solvable multi-physics model.

Experimental transverse resin bleed-out region with fitted area curve — **Measured bleed-out region.** The microscopy image identifies the transverse resin bleed-out area and its time-dependent growth. ComPACT uses this measurement target to calibrate and evaluate how well the model captures resin escape from the compacted laminate.

Experimental and MRT-LBM-DEM transverse resin mass bleed-out over time — **Experimental and MRT-LBM-DEM comparison.** The plot compares measured resin mass bleed-out with the simulated response over time. ComPACT is used here to test whether the MRT-LBM-DEM model can reproduce the observed bleed-out trend, not only the final value.

Case animation. The animation shows the modeled process evolution in a form that is easier to inspect than static plots. ComPACT uses this view to support debugging, interpretation, and communication of the compaction-driven flow behavior.

Case 02

Multiphase resin flow with trapped air and void interaction

Capability: Model how resin, trapped air, and voids interact as pressure-driven flow moves through narrow composite-process features.
What it shows: The simulation tracks an air pocket as it deforms, migrates, stretches, and exits through a constricted flow path while surrounded by resin.
Why ComPACT: ComPACT helps identify where air can become trapped, how resin pressure reshapes voids, and which geometry or process changes can reduce defect risk before testing.

Multiphase flow model showing void and trapped air interaction with resin in a channel — **Void and resin interaction.** This case demonstrates ComPACT's multiphase-flow capability: the software can represent a trapped air or void phase inside resin, follow the interface as it deforms under pressure, and show how flow restrictions influence defect transport and removal.

Case 03

Bilamina characterization testing

Capability: Characterize composite residual deformation by connecting thermal history, material response, and final bilamina curvature.
What it shows: The test tracks deformation during heating, dwell, and cooling, then compares experimental deflection with analytical and finite-element predictions.
Why ComPACT: ComPACT helps quantify spring-in and residual shape change before full-scale trials, supporting faster material screening, cure-cycle tuning, and process-risk reduction.

Residual deformation characterization with bilamina deflection simulation and experiment comparison — **Deflection model validation.** The figure connects simulated bilamina deformation states with a time-history comparison against analytical and experimental deflection. ComPACT uses this workflow to turn residual deformation into a measurable, model-checkable output.

Bilamina characterization testing with measured specimen deformation and simulation comparison at 10 and 450 minutes — **Measured and simulated shape change.** The image shows the specimen at early and late process times beside the corresponding modeled curvature. ComPACT is used to compare observed residual shape against simulation so thermal processing effects can be characterized before scaling the design.

Case 04

Microstructure-informed defect reconstruction

Capability: Reconstruct local laminate defects from microscopy and convert them into simplified simulation geometries with ply orientation and resin-rich regions preserved.
What it shows: The case maps observed 0° and 90° ply paths, resin pockets, and localized waviness from polished cross sections into a model-ready laminate representation.
Why ComPACT: ComPACT provides a bridge between inspection and simulation, helping users turn measured defects into process or structural models that can evaluate how local geometry affects performance.

Local laminate defect reconstruction from microscopy with ply waviness and resin regions — **Local defect mapping.** Microscopy regions are linked to reconstructed ply paths and resin-rich features. ComPACT uses this mapping step to keep the simulated defect geometry tied to the measured composite microstructure.

Laminate defect model showing 0 degree plies, 90 degree plies, resin regions, and axis of symmetry — **Simulation-ready laminate model.** The full reconstruction organizes 0° plies, 90° plies, resin regions, and symmetry boundaries into a clean model input. ComPACT is used here to move from defect observation to a geometry that can support mechanics, flow, or residual-performance analysis.

Case 05

Frontal polymerization process modeling

Capability: Model frontal polymerization by coupling cure kinetics, thermal response, cure-dependent viscosity, and gelation behavior.
What it shows: The case tracks how a curing front develops and how temperature and degree of cure change the resin from a flowable material into a rapidly stiffening network.
Why ComPACT: ComPACT helps evaluate front stability, flow shutoff, and process windows before manufacturing trials, making cure-front behavior visible and easier to tune.

Frontal polymerization cure kinetics and chemo-rheology model workflow — **Cure and viscosity workflow.** The model links cure kinetics, temperature-dependent base viscosity, cure-dependent viscosity growth, and the final chemo-rheology relation. ComPACT uses this chain to predict when resin remains mobile, when it gels, and when flow becomes limited.

Frontal polymerization animation. The video shows the evolving cure-front behavior over time. ComPACT uses this kind of animation to inspect front propagation, identify uneven cure development, and communicate how thermal and rheological feedback drives the process.

Case 06

Particle-fluid interaction benchmark validation

Capability: Validate the micro_ComPact IMB-DEM-LBM solver against published particle sedimentation and two-particle interaction benchmarks.
What it shows: The case compares particle trajectories, velocities, drag-force response, and flow-field evolution against benchmark data from Xia et al.
Why ComPACT: ComPACT uses these benchmarks to build confidence in particle-fluid coupling before applying the solver to resin flow, trapped defects, compaction, and composite manufacturing cases.

Single-particle sedimentation validation comparing ComPACT IMB-DEM-LBM results with Xia et al benchmark curves — **Single-particle sedimentation.** The figure compares ComPACT flow-field snapshots with the published Xia et al. benchmark and overlays vertical position, velocity, and hydrodynamic drag histories. This validates the solver's ability to capture settling dynamics and fluid-particle force transfer.

Two-particle drafting kissing tumbling validation comparing ComPACT results with Xia et al benchmark trajectories and velocities — **Two-particle interaction.** The case captures the drafting, kissing, and tumbling sequence between two settling particles. ComPACT uses this benchmark to test coupled particle motion, wake interaction, and velocity-history prediction before moving to more complex composite-process simulations.