FEA Modeling for Precision Laser Peening

LSP Technologies, Inc. provides laser peening services and equipment, protecting hard-working parts from threatening forces in real-world operating environments. Using finite element analysis (FEA), we can pinpoint exactly how to use laser peening to prevent corrosion, cracking, foreign object damage and high-cycle fatigue.

We can’t change the laws of physics, but we can slow down the effects of vibration, temperature, friction and other factors that try to assault your metal components.
Laser Peening Systems can extend the fatigue life of parts by more than 20 times the expectations for untreated parts.
To obtain those results, we collaborate closely with our customers in a process encompassing precision modeling, precision targeting, and precision execution of a laser peening strategy to extend fatigue life.
FEA modeling can play a key role in the process, matching a precise understanding of customer components with the benefits of laser peening technology.

LSP Technologies uses finite element analysis to understand more about

• Your component design and function
• Operational stresses
• Specific hazards and damage patterns
• Analyze failure modes – cracking, corrosion, metal fatigue, foreign object damage
• Residual compressive stress location and level required for operating conditions
• Appropriate Laser Peening pattern to induce residual compressive stress pattern
• Estimate improvement — up to 20 times normal fatigue life — from the Laser Peening process

Most manufacturing engineers are familiar with the computing power of the Finite Element Method to simplify real-world forces and materials by applying textbook mathematical formulas to components.
“We take the FEA concept a little further. We start with a deep understanding of the part’s geometry and operating challenges. Then we can use FEA to show how the placement, patterns, pulse width, and energy levels of laser shock peening work to create a deep compressive residual stress in the metal part,” said Stan Bovid, LSP Technologies Director of Materials Research.

FEA predicts fatigue life benefits, saving time and money

“We apply both FEA modeling and our library of previous laser peening outcomes to prevent fatigue failure at the exact area of parts where it most frequently occurs. FEA modeling and simulation helps optimize treatments for metal parts well before we do any processing or testing, cutting costs and timelines significantly,” he added.
That’s because LSPT can simulate several parameters of laser peening — energy, pulse width, spot size, pattern and so forth — to optimize the laser peening process for actual stress profiles needed for the parts.
Moreover, FEA modeling can apply operational simulations to predict the service life benefits of laser peening, which typically extends the life of parts by 10 to 20 times their expected fatigue life compared to untreated parts.

The application development process

1. Understand the application and the part.
2. FEA and library analysis.
3. Demonstrate a solution with our Procudo® Laser Peening System.
4. Materials testing to verify fatigue life improvement.
5. Move to production at LSP Technologies or on your production line.

“We apply both FEA modeling and our library of previous laser peening outcomes to prevent fatigue failure at the exact area of parts where it most frequently occurs, and we can reasonably predict the fatigue life benefits for these parts.”
A typical FEA task is to show the application of laser peening to two camshaft lobes and the bearing journal in between the lobes. Laser peening, in this case, creates compressive residual stresses approximately 0.050-inch deep into the lobe, helping to resist spalling, or flaking, of the journal surfaces and to increase the camshaft life.

For more on how LSP Technologies applies FEA for customers, please see the page on Laser Peen Forming, which illustrates how laser peening can provide predictable distributions of plastic strain to more elastic metals, such as aluminum alloys.