Using simulation to improve corrosion risk prediction and analysis

The cost of corrosion

Corrosion is a major threat to any conductive and even painted structure, regardless of the material. It affects performance, safety and cost wherever it occurs. For critical applications, the cost of removing or replacing affected components quickly adds up.

Since 2003, the United States Air Force (Air Force) has spent over $20 billion annually on corrosion, representing over 20 percent of its total maintenance costs. This includes 24 million hours of downtime at $833 per downtime hour. In fact, the funding for the F-22 Raptor Reliability and Maintainability Maturation Program to correct unplanned corrosion issues has almost doubled from $664 million to $1.3 billion.

Estimates suggested that 30 to 40 percent of these costs could be eliminated by using better tools and data when designing new products. Decisions made in military design can last for decades – the B-52 Stratofortress is still in operation 70 years after it was introduced – so manufacturers can’t afford to make mistakes.

Working closely with Simcenter™ Engineering and Consulting services (Simcenter Engineering Services), Corrdesa combined its expertise in electrochemical applications, in this case galvanic corrosion prevention applications, with using Teamcenter® software and Simcenter STAR-CCM+™ software, part of the Siemens Xcelerator business platform of software, hardware and services. This is expected to save the Air Force hundreds of millions of dollars by streamlining corrosion simulation and optimizing designs and material selection.

Integrating corrosion data with simulation

Before working with the Air Force, Corrdesa was already using Simcenter STAR-CCM+ for electrochemical modeling. “Simcenter STAR-CCM+ has several built-in models that enabled us to accomplish what we needed to do,” says Alan Rose, chief executive officer (CEO) of Corrdesa. “These were ideal for corrosion modeling and saved us from having to start from scratch.

“The Air Force was already using Teamcenter and wanted a tool that could be deployed and managed from that. So not only did Simcenter have the necessary CFD capabilities, but it also integrated seamlessly with their existing system.”

Corrosion Djinn is a software as a service (SaaS) platform developed by Corrdesa for managing electrochemical data and quantifying corrosion risk. To meet the Air Force’s needs, Simcenter Engineering Services integrated Simcenter STAR-CCM+ and Teamcenter with Corrosion Djinn to apply the data to 3D models for aircraft design.

Automated modeling

By combining Corrdesa’s simulation expertise with the Air Force’s aerospace expertise, they defined several templates that sped up the modeling of new designs. This automated the creation of geometry and computational mesh, setting boundary conditions with Corrosion Djinn data.

Corrdesa and Simcenter Engineering Services created Java macros for these templates alongside a simplified custom tool graphical user interface (GUI) and a seamless workflow between Simcenter STAR-CCM+, Teamcenter and Corrosion Djinn. This automation enabled Air Force staff without computational fluid dynamics (CFD) expertise to access the relevant data and templates, create a full 3D model made of fastener systems and pieces of aircraft and model the corrosion issues in a matter of minutes.

Based on the materials selected, this provides a prediction of the amount of corrosion or material loss in microns per year. Engineers then have the option to try different materials to minimize corrosion or add sacrificial or barrier coatings to reduce it. Once the materials are finalized, the solution can inform maintenance schedules. Further development is currently underway to more easily include the impact of different environments and mission profiles for aircraft in service, giving a more accurate forecast of maintenance costs.

“This would take so much longer with physical testing,” says Julio Mendez, lead CFD engineer at Corrdesa. “Integrating Simcenter STAR-CCM+ and Teamcenter with Corrosion Djinn delivers all this data in minutes. In previous validation studies we internally carried out and published, we found a deviation of total material loss of around 10 percent compared with results from testing. This suggests we can use the methodology we have developed much earlier in the design process before building physical models. This saves considerable time and cost in the overall development process.”

Saving money with improved designs

In addition to supporting new designs, the toolset is used to qualify potential repair options for existing aircraft, including the U-2 and the C-17 aircraft. This ensures that the Air Force makes the best, most cost-effective maintenance and performance improvement decisions.

Mendez says the partnership with Siemens Digital Industries Software has been crucial to Corrdesa’s success. “We have the corrosion expertise and a unique product in Corrosion Djinn,” he explains. “Using the Simcenter portfolio and collaborating with Simcenter Engineering Services has helped us transform our ideas into reality and deliver this data to customers in the fastest and simplest way.”

Corrdesa is working on a new project that will deploy this solution, “The Corrosion Toolset,” to the Air Force’s cloud platform, enabling the entire organization to use it.

It has been proven this toolset can be used to identify corrosion issues during the design phase so they can be avoided, such as one that cost $228 million to solve in the F-22 Raptor. With the new solution in place, similar issues can be spotted early in design so changes can be made before incurring significant costs.

More integrations for a wider audience

The collaboration between Corrdesa and Simcenter Engineering Services has extended beyond this integration of Teamcenter, Simcenter STAR-CCM+ and Corrosion Djinn. “You can press a button in NX and it will light up your CAD like a Christmas tree showing you where the corrosion risks are,” says Rose. “Our data is fully integrated and hidden – customers don’t need to see it; they just see how their designs will perform.” NX is also part of Siemens Xcelerator.

Simcenter Engineering Services is now helping Corrdesa work toward directly integrating with Simcenter STAR-CCM+ without Teamcenter. “Not everyone has Teamcenter or wants to use it,” explains Mendez. “This direct link will give them the functionality they need while protecting our data and intellectual property.”

Following the successes with the Air Force, Corrdesa is now looking to deploy the same capability to the U.S. Navy and Army. They are also expanding the database to include common automotive materials so it can be used by a broader audience.

“We’re in discussions with automotive OEMs that are going through digital transformation,” says Rose. “They currently have no capabilities for material modeling, compatibility and corrosion. Although many auto companies already have virtual models that are used to analyze stress, aerodynamics, heating and batteries, they do not have specific corrosion modeling capabilities. We provide that.”