Digital Twins for Offshore Infrastructure

Akselos Simulation Technology

North America – Akselos, Inc. ֎ Switzerland – Akselos S.A. Akselos.com

Akselos Enables Full Simulation of the Largest Infrastructure

Globally linear Æ 1000x faster Localized nonlinearities Æ 10x to 100x fasterGlobally nonlinear Æ 1x

Modern computational technologies (parallel, cloud)

Divide-and-Conquer Algorithms (US Patent 9,213,788)

Set parameters and solve (2 seconds instead of 30 minutes)

Assemble model

Create/update RB components

(similar to parameterized

substructuring)

Parameterizedphysics

Computational Approx.

15 Years of R&D Funded by US DoD. More than 100 Publications

100+publications

100+Person years

Peer reviewed papers in top journals. Two text books.

Two Akselos founders are patent authors.

Reduced Basis Algorithms

Leading researchers frommajor academic

institutions

US Patent 9,213,788Funded by US DoD + 20 other Universities

Fast FEA Enables Akselos Digital Twin

Digital Twin: Detailed virtual replica of an entire asset, tracking the current state of the asset(including cracks, corrosion, damage etc.)

� Improved risk assessment

� Simulate extreme events

� Condition-based fatigue analysis

� Predictive maintenance

� Safe lean design

One Global Fine Model of your Entire Asset (1/2)

Standard workflow: DNV-RP-C206

The standard workflow involves juggling many models. Slow and error prone!

One Global Fine Model of your Entire Asset (2/2)

� Global mesh meets all requirements of DNV-RP-C206, e.g. includes 1t x 1t mesh refinement in hot spot areas

� Can incorporate condition-based data in the global model (hull damage, corrosion, etc.)

Akselos provides one global model that uses a fine mesh everywhere

We Provide the Full Range of Analysis…

Contact analysis

Geometric nonlinearity

Buckling analysis

Plasticity

*Akselos’s RB-FEA solvers accelerate the linearregions of the model. We use conventional FEAfor nonlinear regions. Akselos’s Hybrid solverseamlessly couples RB-FEA and conventional FEA.

… and the Full Range of Elements

Shells

Beams

Solids

Hybrid

Solver Capabilities

Analysis Type RB-FEA FEA & Hybrid

Structural 9 Steady-state linear elasticity

9 Dynamic linear elasticity9 Modal analysis9 Node-to-node contact9 The full range of

element types (springs, beams, shells, solids)

9 Plasticity9 Geometric nonlinearity 9 Surface-to-surface

contact 9 Buckling

Acoustics 9 Frequency-domain acoustics

9 Modal analysis

9 Time-domain acoustics

Thermal 9 Steady-state and dynamic linear thermal analysis

9 Nonlinear (temperature-dependent materials)

Parallel Cloud-based Solver

Massively parallelCloud-based solver which can efficiently run 1000s of load cases

Cloud data center One request

Code-based analysis and fatigue analysis can require 1000s of solves

Digital Twin: Integration with Sensors/ IoT (1/2)

Calibrated Digital TwinWind &

Seastates

Accelerometers

Strain

CorrosionWave

Sensors

Cloud-based Servers

Real-time risk-baseddecisions

Digital Twin: Integration with Sensors/ IoT (2/2)

Calibrated Digital TwinWind &

Seastates

Accelerometers

Strain

CorrosionWave

Sensors

Cloud-based Servers

Real-time risk-baseddecisions

Akselos focuses on these links in the value chain.

Partners provide the other links.

The Akselos Digital Twin Safely Avoids Unnecessary Downtime

2.Akselos Digital Twin used to quickly and safely assess the situation. First, the Digital Twin is updated to incorporate the crack in full detail.

3. Thousands of simulations are run

on the updated Digital Twin. With Akselos’s revolutionary simulation algorithms and cloud-based platform, this analysis can be performed within a day.

1. During an inspection,

a crack is identified. The impact and required action are not clear. Is an unplanned shutdown required? Or, can the repair be postponed until the next planned shutdown?

4. Engineers can

then plan and execute the appropriate

response based on accurate simulation

data. The Digital Twin stops unnecessary

downtime.

Akselos GUI

Client’s Model Library

The Akselos Simulation Platform

Simulation Engine

Decision Support System

Comparative Advantage

Example of a Shiploader

Example of a 6,000 ton structure

Load combinations [lc] 100 lc. 30 lc.

Model degrees of freedom[dof] 5 m. dof. 500 m. dof.

Image

Time for FEA, all load combinations 3 days 7.5 hours Too large for FEA

Time for RB-FEA, all load

combinations8 min 20 seconds 1 hour 45 min

Digital Twin Examples

On-shore structures Mining and

port infrastructure Pressure vessels

Wind turbines Offshore structures FPSO

Current Major Project: FPSO Digital Twin

5 Reasons Akselos is Unique

Akselos Reduced Basis FEA is the next generation simulation technology: fast, detailed, accurate.

Parameterized full 3D models which can be reconfigured and re-solved in seconds.

Cloud-based solvers for fast analysis, and enhanced collaboration between engineers.

Results from inspections are incorporated into Digital Twins, which are then re-analyzed based on preset decision support system criteria.

Perform fast 3D solves of entire assets, and include localized nonlinear analysis with conventional FEA where needed.

Appendix

Akselos’s Hybrid “Linear/Nonlinear” Solver is Ideal for Push-over Analysis

Method:1. Start with a fully linearmodel, represented by RB-FEAeverywhere.2. Apply load increments to itas per standard push-overanalysis methodologies3. Once any component thathas stress that exceeds yield, oronce a component requiresgeometrically nonlinearanalysis, it is converted to anFEA component.4. Continue load-steps, modifythe nonlinear region adaptivelyin each step.

This enables a fast, detailed,parameterized approach topush-over analysis.

Traditional Push-over Akselos Push-over

The user must specify plastic regions ahead of time, based on where they expect high stresses to occur.

The approach is fully adaptive and does not require plastic regions to be specified manually. This means we cannot miss critical regions due to “bad guesses”.

Traditional push-over analysis of large structures relies extensively on beamelements because it is too computationally expensive to use shell or solid elements.

Fast RB-FEA solvers make it practical to use shell or solid elements throughout the entire model.

Plastification is assumed to be concentrated at the predefined plastic hinge locations

Spread of plasticity is allowed throughout the volume of the structure

RB-FEA Components Consist of Two Regions: Interior and Ports (1/2)

Interior: The Reduced Basis Method is used to efficiently represent component interiors. This methodology is the product of extensive published academic research*.

The key idea is to create a set of basis functions that efficiently and accurately represent the component’s behavior over the full parameter range of interest. This is achieved by the RB-FEA Greedy Algorithm which efficiently samples the

nonlinear parametric manifold (see Figure on the left). This yields a basis that typically converges at an exponential rate, and hence reproduces full FEA at a small fraction of the computational cost.

*E.g. see: G Rozza, DBP Huynh, and AT Patera, Reduced Basis Approximation and A Posteriori ErrorEstimation for Affinely Parametrized Elliptic Coercive Partial Differential Equations — Application toTransport and Continuum Mechanics. Archives of Computational Methods in Engineering 15(3):229–275,2008.

Ports: RB-FEA components connect to each other on ports. We use modes on the ports to represent the range of behaviors that can be exhibited on component interfaces. Similarly to component interiors, a reduction algorithm is used to choose an efficient port

space. Once again, we typically observe exponential convergence (See the right figure for an example of rapid port mode convergence) with the number of modes, using an optimal reduced set of modes leads to fast and accurate results. **.

**Port modeling is discussed in: Smetana and AT Patera, Optimal local approximation spaces for component-based static condensation procedures. SIAM Journal on Scientific Computing

N=4 N=5 N=6

RB-FEA Components Consist of Two Regions: Interior and Ports (2/2)

Standards-Based Analysis

Akselos component-based models enable standards-based analysis, e.g. output from DNV-RP-C201 is shown below.