FEA Consulting Services 2020 - A Snapshot
Welcome to our overview of Predictive Engineering’s 2020 FEA consulting services. We have tried to make it brief and useful for a prospective client.
We are FEA engineers that are generalists across pretty much all industries. The big difference we bring to our clients is our experience over the decades to ensure that our simulations reflect realty and are not cartoons.
The NASA 5020A specification is written by engineers for engineers. It was one of our more interesting projects since it provided a deep dive into the NASA fastener calculations and leveraged our prior work on bolt / fastener fatigue analysis. At the end of the project, our work was externally reviewed (PDR) and nary a comment was received by our end client.
Fracture and fatigue mechanics is a core wheelhouse activity at Predictive Engineering. Our FEA consultants have years of laboratory and real-world experience in solving industry specific fracture and fatigue problems. We have done projects from navel vessels to submarines to satellites where understanding how laboratory data is applied to as-built structures was the key to the projects’ success. We do not get lost in the math, whether Griffith-Irwin or XFEM, but keep it relevant that for a crack to grow, one has to have tensile stresses (Mode I) and never forget the role of environmentally induced stress corrosion cracking.
FEA of large welded structure used in a hydroelectric installation. The end goal of this FEA consulting project was to verify that the design would meet a 20-year fatigue life. CFD pressure maps were used to simulate the pressure pulses created by the rotating turbine blades. The stress results were then enveloped to create maximum and minimum sets for the final determination of the ASME effective alternating stress range per the ASME Section VIII, Division 2 Part 5.5 Protection Against Failure from Fatigue loading.
Although the ASME Section VIII, Division 2, Part 5.5 – Protection Against Failure from Cyclic Loading code was developed for pressure vessels, it is widely applied in many industries where welded-structures are subjected to high-cycle fatigue loading. The code provides clear guidance on the fatigue evaluation of welded conditions using weld criteria that can be matched to discrete fatigue strength reduction factors. In our work on a large twin-screw auger, the evaluation of welded connections accurately predicted known structural challenges and allowed us to guide the client toward a more robust design.
Our clients turn to us for detailed and accurate stress analysis, even for something simple like this FEA simulation of a truck body. Our engineering reports are developed to provide model verification and a documentation path for our clients. We like to say that another FEA consulting engineer would be able to obtain the same results using our reports as a guidance. We don’t believe in hiding details from our clients since full transparency ensures that they can understand the value of the work and that a documentation trail exists for future work. This level of documentation does add costs to the project, but it also ensures model verification and that we work together as a team.
Our client had an existing die assembly where they wanted greater confidence that it would survive for additional cycles. It is one of our sayings is that we provide “Design Insurance”. FEA simulation is not perfect but it helps our clients avoid multiple prototypes or unexpected last-minute challenges. The analysis was done using LS-DYNA and was completely nonlinear. The objective of the die assembly analysis was to determine its low-cycle fatigue life assuming a limited amount of plastic strain in the die assembly. Results were somewhat inconclusive and provided several interesting conversations between the FEA simulation engineer and the responsible design engineer.
Our business is digital FEA engineering, or one might say, digital prototyping. We bring to bear decades of experience in creating simulations that are digital protypes of to-be-built structures. Our experience allows us to demonstrate to our clients, and verify to external “reviewers”, that it is an accurate simulation and not a cartoon. The structure shown above is a high-temperature regenerative thermal oxidizer (RTO) for the treatment of exhaust gases. The design was shown to pass ASME Section VIII, Division 2 classification with only minor modifications.
This composite analysis work analyzed and validated an advanced composite design thru design loads and into ultimate fail-safe (progressive damage) regime. What made this project of particular interest was the luxury of developing the material models (*MAT_54) from the client’s experimental data. The images above show how failure progressives thru the multi-ply composite. Once validated, the material model was transferred to the “production component”. A standard linear composite analysis was first performed to evaluate the safety margins (failure indices) and then a nonlinear, transient dynamic analysis was performed using mapped CFD loads onto the composite structure. The final structure was field tested and the FEA results were validated.
Linear dynamics (normal modes, steady-state modal frequency, response-spectrum, shock and PSD analysis) is something Predictive Engineering has been doing for +20 years. Our work has been validated, strain-gauged and proven in decades of service. We bring to the table experienced FEA simulation engineers that know the difference between a cartoon and a simulation.
We welcome your inquires on how we can help your business get it right the first time.