ESRD is hosting joint webinars on July 17th and July 29th, both at 1:00 pm EST.

Want to learn from the experts in FEA-based Simulation Application (Sim App) development for standardization & automation of complex engineering analysis tasks, such as 3D fatigue crack growth, 3D ply-by-ply laminated composite analysis or other challenging applications you’d like to safely put into the hands of non-experts?

This July, ESRD will be partnering with several industry leaders to provide not one but TWO stimulating webinars on the latest in FEA-based Sim App development.

The Latest Developments in Sim Apps for 3D Crack Growth Simulations

BAMF Example Crack Front Estimate via StressCheck/AFGROW Integration (courtesy Hill Engineering).

First, ESRD is pleased to join Hill Engineering, LLC (developers of BAMF) and LexTech, Inc. (developers of AFGROW) for a joint webinar on Wednesday July 17, 2019 @ 1:00 pm EST. This collaborative webinar will be titled “3D Crack Growth Simulation: Advancements & Applications“, and will detail the latest technological advancements in Sim Apps for accurate simulation of three-dimensional metallic crack growth via coupled finite element analysis (FEA) and fatigue life computations.

During this webinar, you will see the latest in 3D crack growth predictions via Hill Engineering’s Broad Application for Modeling Failure (BAMF) Sim App, which provides a robust integration between StressCheck’s high-fidelity DaDT/fracture solutions and AFGROW’s crack growth life prediction capabilities.

Additionally, ESRD, LexTech & Hill Engineering representatives will explain how each of their respective technologies seamlessly fit together to enable automated, verified & validated (i.e. backed by experimental data) fatigue crack propagation.

The Importance of Simulation Governance in Sim App Development & Deployment

This joint ESRD/Rev-Sim webinar will explore Sim-Gov compliant Sim Apps for democratization of simulation.

Then, on Monday July 29, 2019 @ 1:00 pm EST, ESRD will join the thought leaders at Revolution in Simulation (Rev-Sim) for a joint webinar on why Simulation Governance compliance is essential to the development & deployment of Sim Apps titled “Democratization of Simulation Governance-Compliant Sim Apps“.

In this timely webinar, we will discuss why it is essential that Sim Apps implement Numerical Simulation technologies which enable the practice of Simulation Governance in order for the vision of democratization of simulations to be realized, as well as why it is important for engineering managers to get on the Simulation Governance train sooner rather than later. Strategies will be explored for democratizing engineering simulations via Sim Apps which are: 1) based on the latest Numerical Simulation technologies, 2) available in Commercial Off the Shelf (COTS) form, and most importantly 3) Simulation Governance-compliant.

More ESRD Webinars…

Interested in the complete ESRD webinar listing, including on-demand recordings from past ESRD webinars? Visit our webinars page here:

Demo of BAMpF/StressCheck interation as run through an AFGROW plug-in (courtesy Hill Engineering)

Announcing Hill Engineering and ESRD Agreement to Jointly Market BAMpF & StressCheck Professional

March 12, 2020

Hill Engineering and Engineering Software Research and Development, Inc. (ESRD) have executed a joint marketing agreement to collaboratively promote the combined use of our software tools Broad Application for Multi-Point Fatigue (BAMpF) and StressCheck Professional, respectively, for the engineering applications of fatigue and damage tolerance analysis.

ESRD is pleased to join forces with Hill Engineering and LexTech, Inc. (an ESRD technology partner and developers of AFGROW) to enable state-of-the-art fatigue crack growth capabilities for DaDT engineers.

BAMpF is a software tool developed by Hill Engineering for predicting the growth of fatigue cracks in 3D parts. Starting from an assumed initial flaw, BAMpF automatically combines fracture mechanics solutions from StressCheck with fatigue life calculations from AFGROW to assess fatigue crack growth performance.

Read Hill Engineering’s announcement.

BAMpF Resources

The following are helpful resources for learning more about the BAMpF/StressCheck/AFGROW integration for fatigue crack growth:

• BAMpF Home page (via Hill Engineering)
• ESRD/Hill Engineering/LexTech Joint Webinar recording (recorded July 2019)
• AFGROW/BAMpF Training workshop (courtesy LexTech/Hill Engineering/ASIP Conference 2019)
• BAMpF Use Case presentation PDF (courtesy Brian Boeke/AFGROW User’s Conference 2019)

BAMpF Case Study Example

The figure below shows a comparison between the fatigue crack growth predicted near a hole (using BAMpF and StressCheck Professional + AFGROW) and results from a fatigue crack growth test for similar conditions. In this case there is an initial flaw at the edge of the hole and the hole has been cold-expanded to introduce compressive residual stress.

Predicted crack front evolution (blue) compares favorably with the observed experimental result (red):

Want to Learn More? Contact Us:

• Hill Engineering
• ESRD

BAMF running as an AFGROW plug-in (courtesy Mr. Josh Hodges/Hill Engineering, LLC)

On July 17, 2019 a joint webinar on the latest developments in FEA-based 3D crack growth simulation, titled “3D Crack Growth Simulation: Advancements & Applications”, was provided by ESRD’s Brent Lancaster, LexTech’s James Harter and Hill Engineering’s Joshua Hodges.

In this webinar, we detailed the latest technological advancements for accurate simulation of three-dimensional crack growth in metallic structures, with and without residual stresses, via coupled finite element analysis (FEA) and fatigue life computations. Additionally, the webinar expanded further on the DaDT analysis best practices presented in ESRD’s June 2017 webinar, titled “Durability and Damage Tolerance (DaDT) Analysis Best Practices“, and highlighted the importance of mitigating the errors of approximation associated with stress intensity factors (SIF’s) and if applicable, engineered residual stresses (e.g. cold-working).

Webinar attendees from a wide range of industries were treated to a demo of Hill Engineering’s Broad Application for Modeling Failure (BAMF) Sim App, which provides a robust integration between StressCheck’s high-fidelity DaDT/fracture solutions and AFGROW’s crack growth life prediction capabilities. The BAMF demonstration showed how to set up a parametric model for DaDT analysis via StressCheck and then, with limited user intervention, integrate with AFGROW and StressCheck via their respective COM API’s to perform an on-demand 3D crack growth simulation. It was very impressive demo, indeed!

View Webinar Recording

Click the button below to view the 3 part, 65-minute webinar recording (scroll to the bottom of the webinar landing page to find the videos):

View Webinar Slides

Click the button below to view the webinar slides (PowerPoint Show):

Additional Resources

During the webinar, we identified several relevant DaDT and/or crack growth simulation resources that may be of interest:

• “Analytical Modelling of Fatigue Crack Behaviour Under Representative Spectrum Loading in the F/A-18 A/B Y508 Wing Root Shear Tie”, Dr. Kevin Walker (DST Group)
• “Crack Aspect Ratio Investigation, Analytical Methods Subcommittee: Round Robin for Cx Holes”, Mr. Robert Pilarczyk (Hill Engineering, LLC)
• “Benchmarking Problems in Fatigue Crack Growth Analyses”, Mr. Robert Pilarczyk (Hill Engineering, LLC)
• “Numerical Simulation Series: Fracture Mechanics Parameters”, Dr. Ricardo Actis (ESRD)
• “Improving Global-Local Simulation Workflows for High-Fidelity Stress and Damage Tolerance Analysis”, Mr. Eric Buettmann & Mr. Gordon Lehman (ESRD)
• “Computation of SIFs for Cracks in Cold-Worked Holes”, Dr. Ricardo Actis & Mr. Matt Watkins (ESRD), Dr. Scott Prost-Domasky (AP/ES) and Mr. Joshua Hodges (USAF)
• “Crack Propagation Analysis Tool for 3D Crack Simulation: A Simulation App Case Study”, Mr. Matt Watkins (ESRD)
• The Contour Method for Measuring Residual Stresses (Hill Engineering, LLC)

Acknowledgments

As always, many thanks to our attendees for their interest and feedback! And, of course, thanks to LexTech and Hill Engineering for their time and contributions. We hope to collaborate on another webinar in the future!

BAMF Example Crack Front Prediction via StressCheck/AFGROW Integration (courtesy Hill Engineering).

ESRD is pleased to join Hill Engineering, LLC (developers of BAMF) and LexTech, Inc. (developers of AFGROW) for a joint webinar on July 17, 2019 @ 1:00 pm EST. This collaborative webinar will be titled “3D Crack Growth Simulation: Advancements & Applications“, and will detail the latest technological advancements for accurate simulation of three-dimensional metallic crack growth via coupled finite element analysis (FEA) and fatigue life computations.

During this webinar, you will see the latest in 3D crack growth predictions via Hill Engineering’s Broad Application for Modeling Failure (BAMF) software tool, which provides a robust integration between StressCheck’s high-fidelity DaDT/fracture solutions and AFGROW’s crack growth life prediction capabilities.

Additionally, ESRD, LexTech & Hill Engineering representatives will explain how each of their respective technologies seamlessly fit together to enable automated, verified & validated (i.e. backed by experimental data) fatigue crack propagation. You don’t want to miss it!

ESRD’s Brent Lancaster discusses StressCheck at the ASIP 2018 conference.

This past week at ASIP 2018, ESRD provided a 2-hour training course titled “Modeling Fastened Connections: Hierarchic Approaches Discussion and Demo”, chatted with attendees about StressCheck and its ASIP-oriented strengths, and exhibited at our attractive booth (above image).

We enjoyed meeting many of the ASIP attendees, connecting with a wide variety of ESRD customers and colleagues, and continuing to share our perspective on DaDT and cold working analysis with the ASIP community. Thanks to those who stopped by to say hello (and grab one of our foam plane giveaways and/or handouts).

ESRD foam plane giveaway (it actually flies!)

ASIP 2018 Training Materials Available…

On November 26th, we had the pleasure of providing a training course on hierarchic modeling best practices (in the context A&D fastened joints) to a full house of interested ASIP engineers. Thanks to those who attended and/or requested the training course materials.

If you are interested in this fascinating topic (and investigating selected StressCheck models from our training course), you can download Mr. Lancaster’s ASIP training presentation, demo video and StressCheck model files here:

ASIP 2018 Training – Modeling Fastened Connections: Hierarchic Approaches Discussion and Demo

We are looking forward to receiving your feedback on our presentation and associated StressCheck model files.

Don’t have access to StressCheck? Request an evaluation of CAE Handbook, which will allow you to open and run the StressCheck model files.

Upcoming Webinar…

Are you looking for best practices and guidance for verifying the accuracy of detailed FEA results?  Don’t forget to sign up for our January 19th, 2019 webinar “How Do You Verify the Accuracy of Engineering Simulations?“:

WATCH THIS WEBINAR

Part 1: Introduction & Implementation Requirements

Part 2: StressCheck & AFGROW Features

Part 3: BAMF Demo & Webinar Summary

ESRD Co-Presents at ERSI Workshop 2019

Interactive K-solver crack propagation (CPAT) in StressCheck used for the prediction of fatigue growth rates.

ESRD’s Dr. Ricardo Actis attended and co-presented with technology partner Analytical Processes/Engineered Solutions (AP/ES) at the Engineered Residual Stress Implementation (ERSI) Workshop 2019 in Clearfield, UT.  This annual workshop is focused on the development of a damage tolerance methodologies for fatigue crack growth through deep Engineered Residual Stress (ERS) fields.

Sponsored by the US Air Force’s A-10 Airframe Structural Integrity Program (ASIP), the goal of this workshop is to develop a roadmap for the implementation of the beneficial effect of engineered residual stresses within the United States Air Force (USAF) Damage Tolerance Analysis (DTA) fatigue crack growth and lifing programs.

At ERSI Workshop 2019, Dr. Thomas Mills (AP/ES) and Dr. Ricardo Actis (ESRD) co-presented “Fatigue Life Modeling at CX and Interference Holes”.  The presentation summary is as follows:

• Crack closure experimental observations and modeling.
  • Continuation of previous year’s work.
• Residual stress redistribution at interference filled holes.
  • Task evolved from USAF goals dictated at ERSI.
  • Goal is to better understand interference fit fasteners and their interaction with residual stresses from cold-working (CX).

A PDF of the presentation may be downloaded at the following link:

ESRD Sponsors the WashU Racing Team

Congratulations to the Washington University in St. Louis Racing Team on a successful season! It was a pleasure to sponsor the team as they improved their global standings in multiple events, and increased their team to over 50 members. Below is a signed image of the racing team members, as well as a letter of appreciation sent to the racing team sponsors:

The 2019 Washington University Racing Team.

Washington University Racing Team Letter to Sponsors.

We are pleased to have a positive impact on our local engineering community, and look forward to our continued sponsorship of the team!

In a previous edition of S.A.F.E.R. Simulation Views, we asked U.S. Navy NAVAIR Systems Command’s David Rusk about the challenges faced by A&D programs.

In this month’s S.A.F.E.R. Simulation Views we asked Brent Lancaster, Principal Support Engineer at ESRD, to discuss the basics of StressCheck Professional:

Q: What prompted the development of your software? What problem(s) is StressCheck meant to solve?

Brent:

Engineering Software Research and Development (ESRD) produces advanced engineering software, powered by higher-order, hierarchical finite element analysis solutions, and offers professional services in numerical simulation for the mechanical, aerospace and structural engineering industries.

Engineering analysis software should simultaneously improve the reliability of numerical solutions while reducing the time required for performing computer-aided engineering (CAE) tasks. This two-pronged strategy reduces costly physical testing and increases reliance on numerical simulation, saving the engineering community manufacturing, machining and design modification costs.

ESRD’s products and services fully embody this strategy, allowing us to establish the reliability of our engineering analyses with hassle-free solution verification and a hierarchic modeling framework that supports validation. ESRD’s flagship FEA software, StressCheck, wins in quality and efficiency by converging to the exact solution at a higher rate than our competitors, while simultaneously providing engineers crucial feedback that the model is fit for validation. Saving time and money while ensuring the quality of the answers, makes StressCheck the world’s premier high-definition, detailed numerical simulation tool.

StressCheck’s key solutions include detailed stress analysis, contact, global to local, laminated composites, fracture mechanics and engineered residual stresses due to cold-working, machining or other forming operations.

Q: What are the benefits of using StressCheck for fracture mechanics simulation?

Brent:

When performing fracture mechanics tasks, StressCheck users receive the high definition feedback information needed to establish the reliability and accuracy of the computed stress intensity factors (SIF), beta factors and energy release rates (ERR). This information is essential for accurate life prediction and damage tolerance assessment (DTA), a rapidly expanding need in the aerospace industry and beyond.

Some of the highlights of StressCheck’s fracture mechanics features are:

• Superconvergent SIF extractions – converges in less time that our competitors with fewer requirements for meshing.
• 3D crack insertion capability – model any crack shape, anywhere in a parametric or imported CAD part, with specialized meshing tools for accurate beta factors extraction.
• Point and click SIFs – get converged results anywhere along the 3D crack front to improve crack growth predictions.
• Combine global-local, contact and fracture mechanics seamlessly – no special elements, solvers or tricks required.
• Influence of residual stresses – incorporate coldworking, subsurface or bulk material residual stress effects when computing SIFs.

 

Q: Are there any unique applications that StressCheck works for that your competition cannot?

Brent:

Predicting fatigue-critical peak stresses and associated stress gradients in CAD parts with small and complex features is an application that is a huge challenge for our competitors. This is because their implementations are not designed to seamlessly quantify and separate discretization errors from modeling errors. Our competitors’ lack of this fundamental post-processing feedback limits the complexity of applications that can confidently be performed by their software, even for an application as basic as the one above.

As a result, many of ESRD’s customers rely on StressCheck as their go-to FEA solution for life extension, damage tolerance, plastic failure, fastened connections and laminated composites because they know they will get the correct answer.

Q: How much time does it take to learn and start using StressCheck?

Brent:

In order to establish the reliability of its solutions, StressCheck implements a more technologically rigorous approach to the finite element method (FEM) than our competitors. When coupled with a feature-rich interface supporting variable inputs and restriction-free outputs, StressCheck users will need more familiarity with the software in order to harness its full range of functionality.

If the application is as simple as importing a 3D solid, automeshing, applying material properties and BCs, solving a hierarchic series of increasingly refined solutions, plotting stress fringes and verifying the maximum stress converges to a limit, which is independent of the discretization, can be accomplished in less than an hour. In general, new StressCheck users can get up to speed in a manner of days or weeks, depending on the complexity of the application or the goals of the analysis.

See the above workflow performed in this step by step ESRD StressCheck Tutorial: Import CAD and Analyze Stress video.

More advanced or demanding applications, such as laminated composites, contact or cold-working analysis, may necessitate consulting the StressCheck Master Guide, visiting ESRD’s Customer Portal for best practices and demos, or hands-on training from a qualified ESRD representative.

To get started and become familiar with basic StressCheck features, we recommend first watching a broad-stroke overview of the StressCheck user interface and a sample workflow in this StressCheck Tutorial: GUI Walkthrough video.

Q: What are the biggest challenges or problems that customers in your target market face and how do you address their needs?

Brent:

Engineers involved in detailed analysis find that getting the right answer quickly and accurately is often difficult to achieve. Efficient simulations with error control are what make StressCheck stand out among the competition. StressCheck’s hierarchical modeling engine coupled with its separation of model definition (idealization) and numerical approximation helps ESRD’s clients find the correct answer quickly, an answer backed up automatically with data to show just how accurate within a range of tolerance (for example, an answer can be verified to be accurate within a margin of error of 2%).

Once the model is solved, engineers in many cases become interested in results different from what they originally had in mind.  In other words, they expect to have complete freedom in post-processing.  StressCheck allows users to live-query any location and any output within the area of interest, not requiring predefinition and eliminating the need to re-run the simulation if the user requires results outside the scope of the mesh design.

See an example of live-query results processing in this StressCheck Demo: Live Dynamic Extractions video.

Q: Describe a typical workflow using ESRD’s StressCheck.

Brent:

Imagine an engineer wants to quickly import a Parasolid assembly, incorporate a part-thru crack at a location, perform a multi-body contact analysis for more accurate interactions, and verify that the crack SIFs are converging well.  Here is the ideal workflow to complete the task:

• Import the Parasolid assembly using our file importation feature.
• Create or import the crack surface to be analyzed and insert into a flight-critical location in the assembly using the Boolean-Union method, resulting in a part-thru crack.
• Assign external loading (tension, bending, etc.) and constraints (fixed, spring, etc.) to the surfaces of the assembly and ensure that the assembly is properly constrained to prevent rigid body motion.
• Assign contact pairs to ensure the assembly transfers the load in contact regions.
• Tetmesh the assembly using curved elements and specialized meshing tools for the part-thru crack, including the Crack Face and Boundary Layer methods, for optimal grading.
• Define and assign material properties to the mesh.
• Solve the assembly via StressCheck’s automatic p-extension process, coupling its efficient contact algorithm with a powerful hierarchic element formulation, iterating until the difference between contact pressures of two consecutive iterations is sufficiently low.
• Check the quality of the load transfer and contact pressures to verify the solution is reliable.
• Plot the deformed shape to ensure that the part is deforming as expected, and the crack face is opening.
• Check convergence of SIFs at any location on the part-thru crack with fast Point and Click extractions.
• Query high-resolution gradients of SIF information along the crack front when multiple locations along the crack are used in crack growth.

 

See a similar workflow in action in this StressCheck Tutorial: 3D Elliptical Part-Thru Crack with Multi-Body Contact video.

Do you have a parametrized assembly, crack shape or loads?  Just change the relevant parameters and click Solve.  It’s really that simple: no tricks, shortcuts, or solver magic.

Q: What’s next for ESRD, what can we look forward to?

Brent:

There is an increasing demand in the engineering community for advanced capabilities in residual stress and crack extension analysis. Distortion due to machining and surface treatments such as shot peening are in need of refined solutions. With each StressCheck release, ESRD expands its analysis portfolio to account for challenges like these.

Speaking of StressCheck releases, we expect to release our next version, StressCheck v10.5, in Spring 2019. Be sure to subscribe to our newsletter to receive updates about our next product release.

For more information about ESRD’s StressCheck Professional, visit https://www.esrd.com/stresscheck-professional

Stay Up to Date on StressCheck Professional…

Corner crack at the edge of the hole inserted after cold-working. Contour show the progression of crack opening as the external load is increased from 0 to 27 ksi. First noticeable crack opening appears around 19 ksi.

ESRD’s Dr. Ricardo Actis attended and presented with technology partner Analytical Processes/Engineered Solutions (AP/ES) at the Engineered Residual Stress Implementation (ERSI) Workshop 2018 in Clearfield, UT.  This annual workshop is focused on the development of a damage tolerance methodologies for fatigue crack growth through deep Engineered Residual Stress (ERS) fields.

Sponsored by the US Air Force’s A-10 Airframe Structural Integrity Program (ASIP), the goal of this workshop is to develop a roadmap for the implementation of the beneficial effect of engineered residual stresses within the United States Air Force (USAF) Damage Tolerance Analysis (DTA) fatigue crack growth and lifing programs.

At ERSI Workshop 2018, Dr. Ricardo Actis (ESRD) and Dr. Thomas Mills, Dr. Scott Prost-Domasky, and Mr. Craig Brooks (AP/ES) presented “RS Crack Closure: Experimental Observations and Modeling”, the PDF of which can be downloaded below:

The ERSI Workshop 2018 attendees are shown below:

Attendees to the Third ERSI Workshop.

ESRD, Inc. continues to work closely with AP/ES and the USAF to develop and implement accurate solutions for challenging Durability and Damage Tolerant applications.