Mondaic Ltd.

We are pleased to announce a collaborative project (and a research position!) with Bundesanstalt für Materialforschung und -prüfung and Vallen Systeme GmbH, on Digital Twins for Acoustic Emission in Pre-Stressed Reinforced Concrete. Pre-stressed concrete is used in many large structures, and particularly bridges. However, the tension wires within the concrete are prone to corrosion and fatigue, which can lead to structural damage and failure. Monitoring the health of the wires within the concrete requires acoustic emission analysis, which is often costly and labour intensive. This project develops a novel, reliable and automated technology to improve monitoring using acoustic emission testing. Simulating acoustic emission in digital twins of reinforced concrete structures using #Salvus will help to guide optimal sensor positions for real-world structural monitoring, and discrepancies between the calibrated digital twin and real data can highlight possible tension wire breaks. Research position at BAM: https://lnkd.in/eA6_WXu5 Many thanks to Innosuisse and ZIM for supporting this IraSME project AiF Projekt GmbH Please see the report (in German) for further details! #AcousticEmission #DigitalTwin #BridgeCollapse

📢 Paper Alert - Salvus User 📢 Investigating Subsurface Properties of the Shallow Lunar Crust Using Seismic Interferometry on Synthetic and Recorded Data  https://lnkd.in/epCYMuMP With future lunar missions from several international space organisations now in preparation, it is important that we understand which scientific measurements may yield useful results on the moon. Seismic interferometry studies could reveal the presence of potential ice-bearing rocks and/or cavities beneath the lunar surface, which would improve our understanding of the moon’s structure, as well as potentially providing resources for further crewed missions.  This study uses a combination of measured data from the 1972 Apollo 17 mission and synthetic data to evaluate the potential of seismic interferometry on the moon, and to quantify required measurement duration and optimal measurement time within the lunar cycle.    #Salvus is used to reproduce measured data in 2D – the first step towards creating a digital twin of the moon’s shallow crust. The synthetic results show that scattering effects clearly influence the extraction of Green’s functions, especially for larger station distances. This helps to constrain maximum inter-station distances for future lunar seismic array deployments. Figure: Comparison of recorded (rec) and simulated (sim) data for one explosion shot of the Apollo 17 active seismic experiment for one random model:  (a) Waveforms  (b) Envelopes  (c) Spectra Image source: Appendix Figure A5 from the paper; published under CC BY 4.0 https://lnkd.in/e365Whs    Disclaimer: This work was carried out by researchers from Ludwig-Maximilians-Universität München Munich and Geociencias Barcelona del CSIC (GEO3BCN-CSIC). Mondaic was not directly involved in this research, but we are proud to see Salvus being used in such an exciting project. #seismology #space #interferometry

📢 Paper alert – Salvus User 📢 In Situ Velocity-Strain Sensitivity Near the San Jacinto Fault Zone Analyzed Through Train Tremors  https://lnkd.in/erJWacBM    Earth’s tidal strains can affect the speed at which seismic signals travel. When studying tectonic strain accumulation and the nucleation of earthquakes, it can be beneficial to understand the effect of tidal strains. For example, fractures in a rupture zone decrease the mechanical strength of the rock, making it more likely to deform under tidal forces. A useful metric for this is velocity-strain sensitivity: the ratio between the relative velocity change and strain perturbation.    This study uses freight trains as P-wave seismic sources, as they travel along the San Jacinto Fault Zone in southern California. P-wave correlation functions are computed using train signals recorded by a dense nodal array.    Salvus is used to simulate the P-wave correlation function, taking into account the layered velocity profile and source-receiver configuration. These simulations help to constrain variations in the velocity-strain sensitivity with depth, resulting in a depth decay rate that is smaller than previously assumed. Figure: Overview of numerical experiments:  (a) Comparison between simulated and observed P-wave correlation functions. Rectangle highlights P-wave package.  (b) Normalised structural sensitivity kernel for P-wave travel time.  (c) Simulated differential P-wave travel time compared to reference value, for combinations of surface sensitivity and decay rate. Darker colours represent smaller deviations from the reference. Crossed boxes indicate combinations not considered in the simulation.    Image source: Figure 5 from the paper; published under CC BY 4.0 https://lnkd.in/e365Whs    Disclaimer: This work was carried out by researchers from the University of Science and Technology of China, Université Grenoble Alpes, the Geological Survey of Denmark and Greenland, UC San Diego, and the University of Southern California. Mondaic was not directly involved in this research, but we are proud to see #Salvus being used in such an exciting project.   

Ground Motion Modeling Dashboard  https://lnkd.in/e6KFyqPR    While earthquake simulations may be a valuable tool for understanding potential seismic ground motion and hazard in an area, running such simulations often requires a significant amount of coding and computational knowledge. At Mondaic, we are endeavoring to make our powerful Salvus simulation software usable for a wider audience.    As part of the @DT-GEO project, we have developed a demo ground motion modeling dashboard that would enable users to upload a QuakeML file for an event, configure their simulation, run it and explore the outputs, all within a browser window. This includes options to:  - Specify the extent of the domain  - Run simulations both locally and on remote machines, such as through SSH connections or HPC schedulers  - Input 3D information such as velocity models and local topography  - Visualize metrics such as PGA (Peak Ground Acceleration) in browser, or export time series, as well as all wavefield simulation outputs, to visualize elsewhere    For further details, see the full case study on our website.    #hazard #risk #earthquake #modeling 

Detection of Wind Turbine Blade Spar/Shell Adhesive Debonding in Manufacture Manufacturing defects, including spar debonds, have been identified as a source of blade failures in recent root cause analyses. Using a CAD model of a wind turbine blade generated using Sandia National Laboratories PyNuMAD, we are able to simulate the propagation of a guided ultrasound wave several metres along the blade using #Salvus. Our simulations show good sensitivity to 10 x 2 cm and 5 x 2 cm debonds with a single transducer position. Our solution simplifies the current time-consuming approach of performing an ultrasonic C-Scan on every blade, and could bring inspection forward in the production process, allowing for remedial action to be conducted at an earlier stage. This would likely improve the throughput of blades in a factory.   We are looking for a partner to help validate our simulations, particularly with real blade samples containing defects! If the detection of debonding is a problem for you and you would like to know more, please reach out to us at info@mondaic.com .   Animation and simulation: Lars Gebraad Project lead: Chris Udell #ndt #windturbine

Are you using acoustic emission testing for monitoring storage tanks or pressure vessels? Have you even wondered how the ultrasonic wavefield interacts with the geometry and the liquid inside? Digital twins can help with sensor placement and maximise your POD (Probability of Detection). Through the use of simulations, we can see through sound! Thanks to Vallen Systeme GmbH for bringing this topic to our attention. #ewgae #acousticemission #digitaltwin #ndt #monitoring Animation by Patrick Marty

Fresh out of the oven! We had an intriguing day putting our latest CFRP stiffened panel into the autoclave to cure at Switzerland Innovation Park Zurich. Let’s see what defects are hidden inside! Stay tuned to see what Mondaic’s W-Scan technology will find. Many thanks to Christian Brauner and his group at University of Applied Sciences and Arts Northwestern Switzerland FHNW for constructing the panel! Furthermore, this project would not have been possible without the team of Johan Robertsson at ETH Zürich and the support of Innosuisse and ESA BIC Switzerland. Thanks to many colleagues for their contributions, including João Francisco, Sabrina Bättig, Julian Kupski, Henrik Rasmus Thomsen and Dirk-Jan van Manen. Photo credits: Lars Gebraad #NDT #composites #SHM #materials #aerospace #wscan

We had a very insightful time at the Geo-INQUIRE Workshop “Toward Data Lakes for Recorded and Simulated Earthquake Ground Motions” at Helmholtz-Centre Potsdam - German Research Centre GFZ this week!    A data lake is a repository that ingests and stores large volumes of data in their original forms. This workshop aimed to bring together scientists working across disciplines, to discuss opportunities and challenges around using ground-motion simulation in the construction of ground-motion models and data that are useful for the engineering community.    Many thanks to the organisers for facilitating this event – particularly Fabrice Cotton and SSU-TING LAI – and the attendees for fruitful discussions!    DT-GEO #Seismology #Earthquakes #Engineering

📢 Paper alert – Salvus User 📢 Numerical Modeling Predicts Seismic Resonances in the Magma Chamber-Conduit System due to Wavefield Capturing  https://lnkd.in/dz9WaX28     Analysis of the seismic signals observed in the vicinity of volcanoes can provide information about the internal structure of the volcano itself and help us to gain a better understanding of the magmatic processes taking place that we are unable to see from the surface.    However, understanding the seismic signals can be a challenging task, given the wide range of signal characteristics seen and their possible causes. For example, one may be dealing with a combination of volcano-tectonic events, tremors and resonances.    This study uses #Salvus to simulate wave propagation from a double-couple source through a range of models of a magma chamber and conduit, both with varying diameters. Significant resonances are observed, particularly in systems with larger magma chambers and wider conduits. Such signals may appear similar to tremor when observed using seismometers at the surface.    Figure: Visualisation of the z-component of the wavefield at various time steps throughout the simulation:  (A) Shortly after excitation of the wavefield at a source  (B) Capturing of the incident wavefield within the magma chamber  (C) Reflection of the wavefield at internal boundaries within the magma chamber-conduit system  (D) Reverberations within the magma chamber and conduit induce ‘calabash resonances’    Image source: Figure 2 from the paper; published under CC BY 4.0 https://lnkd.in/e365Whs    Disclaimer: This work was carried out by researchers from Goethe University Frankfurt, FIAS - Frankfurt Institute for Advanced Studies, and the Institute for Geothermal Resource Management. Mondaic was not directly involved in this research, but we are proud to see Salvus being used in such an exciting project. 

Tools for Simulating Seismic Hazard in Switzerland https://lnkd.in/dtvxEWqm    Earthquake simulation can be a valuable tool to try to understand the seismic hazard in an area, including in regions with little historical data due to low rates of seismicity.    #Salvus provides a wide range of tools to accurately simulate earthquake ground motion, including the ability to incorporate topography, complex velocity models, anisotropy/attenuation, realistic boundary conditions and complex planar fault sources. The massively parallel implementation of Salvus (on both CPUs and GPUs) also facilitates rapid simulations.    Users can output an assortment of useful metrics for earthquake intensity, including peak ground velocity (PGV), peak ground acceleration (PGA), significant duration, macroseismic intensity and more.    Here, we show an example of the simulation of the historic 1365 Basel earthquake, estimated to have had a magnitude between 6.0 and 7.1. We utilise a realistic velocity model of Basel, including topography, to simulate the macroseismic intensity across the whole of Switzerland.    See the full case study on our website for further details of this work carried out with DT-GEO and Swiss Seismological Service (SED) at ETH Zurich.   #hazard #risk #earthquake #digitaltwin