Tennessee’s Best Kept Secret

“Curiosity is lying in wait for every secret”-Ralph Waldo Emerson. 

Tennessee Automotive Manufacturers Association

VEXTEC is a member of the Tennessee Automotive Manufacturers Association (TAMA)

Perhaps this was the goal of Tennessee Governor Bill Haslam in June when he returned from his economic development trip to Asia unwilling to share details with the public.  Soon after his departure, a flurry of news reports and blogs surfaced wanting to know why he would not share the details of his agenda with the public. His spokesman David Smith’s response was, “we don’t talk about private meetings.”  This left many to speculate if he was courting another automotive manufacturer to open up shop in the mid-state and what incentives and tax breaks were being offered to sweeten the deal.

This would not be too far off base considering the automotive industry in Tennessee has been increasing steadily each year and that Volkswagen recently announced further expansion of their production plant in Chattanooga. Even though the industry is growing at record rates there are real weaknesses which must be addressed in order to sustain the growth rate. The Brookings Institute conducted a study in 2013 titled, “DRIVE! Moving Tennessee’s Automotive Sector Up the Value Chain” and uncovered several challenges that that could stunt the growth of this life line to the state’s economy.  One of these three challenges identified in the study is insufficient private research & development (R&D) resources and shortage of collaborative technology development throughout the Tennessee auto supply chain.

It seems, however, there may be another “best kept secret” here in Tennessee and that is VEXTEC Corporation.  VEXTEC, founded in 2000 and operating in Brentwood, TN, is an engineering and design simulation company that specializes in providing predictive tools and computer aided engineering services in the areas of product reliability, risk assessment and durability prediction for manufacturing companies of structural, mechanical and electronic products.  While it could appear they are a secret in their home state, VEXTEC is well known in both federal and commercial engineering communities across the nation receiving over $25 million from the United States Department of Defense since 2000 and recognized in 2009 by Forbes magazine as “America’s Most Promising Company“.  In fact, they even have a history with Detroit and were profiled alongside Ford Motor Company in an issue of WIRED Magazine on the automotive industry titled, “Why Things Fail: From Tires to Helicopter Blades, Everything Breaks Eventually.

The next article in this four part series will expand on the WIRED article and how VEXTEC is using probabilistic models and simulation technology to improve warranty management, increase design, reliability within limited testing budget constraints   and decrease production downtime for the automotive industry.  In the meantime, if you are curious and would like more information on VEXTEC’s services and their successes in the automotive or other industries, visit vextec.com or click here request a call or more information.

VEXTEC Corporation is a member of the Tennessee Automotive Manufacturers Association (TAMA).

VEXTEC Presents At The Medical Device Innovation Consortium’s First Modeling and Simulation Summit

Dr. Sanjeev Kulkarni, VEXTEC Vice-President

Dr. Sanjeev Kulkarni, VEXTEC Vice-President

VEXTEC Vice-President Dr. Sanjeev Kulkarni made a presentation at the Medical Device Innovation Consortium’s (MDIC) first modeling and simulation summit in Washington, D.C. The presentation was titled “Computational Modeling of Medical Devices Using Virtual Life Management.”  Dr. Kulkarni discussed two major challenges facing the medical device industry, which are:

• High cost and time of testing

• Risk of recall

He then showed how VEXTEC’s Virtual Life Management software can be used to calculate the statistical distribution of the lifetime of medical devices. VEXTEC’s approach had been shown to reduce the amount of testing needed, which reduces cost and time to market. It also improves the accuracy of life calculations, which reduces the risk of recall, which is expensive and damaging to a company’s reputation.

The event was MDIC’s first public summit devoted entirely to advancing the use of computational modeling and simulation in the development and evaluation of medical devices.  The meeting featured panel sessions and podium presentations on combining experiment and simulation to inform clinical trials, creating data repositories to support the industry-wide use of M&S, and other relevant topics. The summit brought together people from the medical device and software industries, academia, and government regulators.  Session chairs included:

• Dawn Bardot: Senior Program Manager, Modeling and Simulation, MDIC

• Tina Morrison, Advisor of Computational Modeling, Office of Device Evaluation, FDA

• Kyle Myers, Director of the Division of Imaging and Applied Mathematics, Office of Science and Engineering Laboratories, FDA

• Randy Schiestl, Vice President, Global Technology, Boston Scientific Corporation

Starting this summer, MDIC will host a series of teleconferences to share success stories and discuss future applications of modeling and simulation in the development and regulation of medical devices. MDIC has also formed working groups to investigate six priority issues in the arena of modeling and simulation:

• Combining simulation and bench experiments to inform clinical trials.

• Creating a library of models and data to support the industry-wide use of modeling and simulation.

• Simulation of the heart, vasculature, and related medical devices.

• Modeling of magnetic resonance-induced heating.

• Modeling and simulation in orthopedics.

• Simulation of blood damage.

About MDIC:

The Medical Device Innovation Consortium (http://mdic.org/) is a public-private partnership to advance regulatory science in the medical device industry. The MDIC coordinates the development of methods, tools, and resources used in managing the total product life cycle of a medical device to improve patient access to cutting-edge medical technology.

NAVAIR Awards VEXTEC Contract to Determine the Effect of Complex Loads on Helicopter Gearboxes

Complex Mission Loading PlotJune 13, 2014 -Brentwood, TN — The Naval Air Systems Command has awarded a fourth contract to VEXTEC Corporation to help improve helicopter durability. Gearbox durability is an important part of helicopter safety and reliability. VEXTEC is working with the Navy on a helicopter tail gear box (TGB). The particular component under investigation is the shaft, which is part of the transmission system that transfers torque to the tail rotor. The tail rotor counters the torque of the main rotor, and is essential for the pilot to control the aircraft. Fracture of the shaft will disrupt power to the tail rotor. During extreme operational conditions, fatigue cracks can initiate and grow in the shaft. The Navy has undertaken steps to determine the root cause of this cracking.

Once this has been determined, appropriate design changes will be made. The overall purpose of the program is to determine the crack growth rate of very small cracks propagating in the shafts under relevant operating conditions, and the expected spline durability once cracks initiate.

The program will provide essential data for fracture analysis. Specimens fabricated from an actual TGB shaft will be tested at representative mission flight loads to develop reliable crack propagation rate and stress intensity factor curves. The stress intensity factors determine what state of stress is sufficient to actively propagate a crack and how many cycles the shaft can survive before failure. Both of these quantities are strongly influenced by the actual fabrication process.

The Navy has been testing for the fatigue failure mode on the shafts under combined torsion and bending loads to isolate the failure cause and develop design improvements. VEXTEC is conducting additional fatigue crack growth tests on specimens cut from the shafts under variable mission loading conditions. The specimens are an arc sector of shafts that have been used in operation and have the geometry, residual stresses and surface condition of actual shafts. Traditional crack growth specimens are of simple rectangular geometry with machined large cracks. A test fixture has been designed and built to replicate the loading of the actual shaft in operation.

A major contributor to component durability is the mission load sequence that the component experiences in operation. In traditional crack growth testing, data is taken at constant amplitude load and the variable amplitude effects are not determined. The objective of this program is to determine the influence of mission overloads, offloads and sequence on the component material crack growth rate as well as the threshold loading for the crack to grow and the critical loading to cause fracture. This information is critically important since it determines the effect of operational loading on the shaft durability. Successful completion of this effort will provide reliable data to complement the fracture analysis.

About VEXTEC:

VEXTEC (http://vextec.com) was founded in 2000 and has developed its patented technology on virtual material modeling and predicting product durability. VEXTEC offers its Virtual Life Management (VLM) services to a variety of commercial and government customers.

Contact:

VEXTEC Corporation

Ashley C. Clark

Marketing Manager

(615) 372-0299 (ext. 233)

aclark@vextec.com

VEXTEC Article Published in February Issue of Gear Solutions Magazine

VEXTEC article featured in February issue of Gear Solutions magazine

VEXTEC article featured in February issue of Gear Solutions magazine

Feb. 17, 2014 – Brentwood, Tenn. – The February issue of Gear Solutions Magazine features an article  from VEXTEC entitled “Using Integrated Computational Material Science to Create Virtual Simulations of Gear Fatigue Life.” The team of authors included Ganapathi Krishnan, Richard Holmes, Robert Tryon and Ed Pope of VEXTEC along with Richard Warns of Chrysler and Vikas Tomar of Purdue University. Former Purdue University Aeronautical Engineering Head Thomas Farris (Now Dean of Rutgers School of Engineering) and his graduate students also contributed. Portions of the article describe work that was funded by the U.S. Naval Air Command.  The program paired VEXTEC’s probabilistic modeling capability (called Virtual Life Management or VLM) with Purdue’s CAPRI software, which models local surface stresses near contact points. Chrysler provided an extensive amount of test data of 9310 case hardened sun gears that were subjected to many demanding cycles on a dynamometer. Although designed to industry standards, about 4% of tested gears showed pitting damage.  VEXTEC’s simulations also showed that 4% of gears would suffer pitting damage. The Navy was interested in using the VLM approach to analyze helicopter gears, which were made of Pyrowear 53. Notched, three-point bend data from technical reports were used to calibrate the model. Analysis was then performed on baseline gears, and those which had been superfinished to a very smooth surface.  Virtual Life Management showed that superfinishing more than doubled gear life. The goal of the program was to develop a model that could quickly evaluate changes in design, material or processing. This was accomplished with probabilistic models that simulated the actual failure process. The benefits of this approach include (1) Reduced physical testing, (2) Accelerated research and development plus reduced time to market, and (3) Reduced warranty costs due to increased accuracy of life calculations. This approach can be used on all kinds of components, not just gears. To date it has been used in the aerospace, automotive, defense, electronics and medical device industries. Click here to View the Full Article in Gear Solutions Magazine.

 

VEXTEC Awarded $800,000 Naval Corrosion Analysis Contract

Jan. 11, 2014 BRENTWOOD, Tenn. — VEXTEC recently received funding from the Office of Naval Research to continue work on “Corrosion Resistant Naval Alloys: Innovative Multi-Scale Computational Modeling & Simulation Tools.” This multi-year, $800,000 contract supports the Sea-Based Aviation National Naval Responsibility program.

VEXTEC will create software to serve as an integration tool that links the results of research on corrosion fatigue into a usable structural analysis tool. Fatigue failure due to corrosion is a multi-disciplinary, multi-scale problem. In order to accurately simulate this failure, integration of many mechanisms is required and better prediction of failure risk is necessary. The Navy’s objective is to take advantage of all available corrosion fatigue knowledge, methods, models and algorithms to fulfill this vision. The overall concept is to develop a tool set which has a library of different material microstructures, damage models, and solving routines to simulate corrosion fatigue failure. An additional feature of the tool is that it will allow users to integrate their own individual computational damage models or solving routines within the software tool. This feature will be analogous to most commercial finite element analysis (FEA) software tools that contain a library of their own different element types and solver routines for structural analysis, but also allow users to link their own special solving routines and specialized elements.

About VEXTEC:

VEXTEC (http://vextec.com) was founded in 2000 and has developed its patented technology on virtual material modeling and predicting product durability. VEXTEC offers its Virtual Life Management (VLM) services to a variety of commercial and government customers.

Contact:

VEXTEC Corporation

Ashley C. Clark

Marketing Manager

(615) 372-0299 (ext. 233)

aclark@vextec.com

Product Reliability in the Medical Device Industry: Lab Testing Is Not Indicative of True Failure

Product Reliability in the Medical Device Industry: Lab Testing Is Not Indicative of True Failure

Brentwood, TN, August 28, 2013:  A recent TV commercial on medical implants caught my attention. While touting the benefits of extensive laboratory testing, the fine print said that “…results of the testing have not been proven to predict clinical wear performance…” How true. Laboratory testing is rarely indicative of true wear and does not predict actual product reliability in the medical device industry.

Testing is a necessary and vital element in the development of emerging device designs. However, testing alone in a laboratory setting is not adequate in guaranteeing the reliability of a device. Things that perform brilliantly in laboratory testing have been a disaster once deployed. A critical issue in certifying device reliability is the fact that in-patient failures often derive from non-typical damage conditions. One cannot test for high reliability. A failure rate as low as 1 in a 1000 can cause the manufacture to recall a device. At these rates, failures are driven by tails of the statistical distributions of loads, geometry and material properties. One just cannot test enough samples to understand what is going to cause failure in the patient population. One can test for “worst case” or accelerated failure conditions but it is difficult to know if worst case is 1/100, 1/1000 or 1/10000 failure rate. So it is not possible to quantify device reliability. Developmental testing at a specimen or sub-component level is required. These tests are useful in identifying gross design flaws, and the results of these tests must be used to calibrate or validate the full scale design models in the context of the actual usage conditions along with identifying important quality control parameters, but they cannot be used to predict reliability.

The medical device industry may have some catching up to do with regard to using additional tools to improve reliability and reduce recalls. The improvement in reliability in other industries has been driven by the use of computational models as an additional tool to physical testing and quality control. Computational models with probabilistic methods have been used in aerospace, automotive, civil structures and other industry to predict reliability and identify the most probable sets of conditions that will produce unacceptable failure rates. Computer aided design (CAD), finite element analysis (FEA), computational fluid dynamics (CFD), and material and manufacturing specification are combined to create a model that is a digital representation of the device such as the “Virtual Twin®” used in VEXTEC’s Virtual Life Management® (VLM®). The input values to the model are statistical distributions with estimated uncertainties. Automotive engineers use these models to computationally “drive the fleet” where the variation in manufacturing, usage, maintenance and repair are simulated to predict the incidents of failure of each of thousands of components. If a supplier produces a lot of 200 parts that do not meet a material specification, the model is ready to be used to simulate the risk of failure if the parts are accepted and put into production long before tests can be completed. Or even worse, if the 200 parts slipped through quality control, the models are ready to simulate risk and determine if a recall is required.

VLM recognizes the critical role of the random nature of damage accumulation in a population of patients. It provides a better means for using and assessing the results obtained from relatively few laboratory/animal/human tests which, by themselves, are unable to characterize the randomness that is critical to population-wide damage tolerance and risk assessment. VLM provides a technique for assessing the scatter in the behavior of clinical damage rather than simply relying on purely statistical safety factors for all operations. These empirical scatter factors do not differentiate between the sources of scatter such as patient type, patient activity level, damage type and locations, material lots and production methods. The safety factors today rely solely on the acquisition of great amounts of empirical field data thereby combining all factors in a single, undifferentiated life factor. The empirical approach means that the minimum life prediction capability often follows a critical recall, rather than anticipating it.

There was a feature article in Wired Magazine last November on the issue of product failure entitled “Why Things Fail”. The article provided a discussion of recall, warranty and reliability in various industries and what engineering does to try to avoid failures including computational simulations. But warranty is not just an engineering problem. Poor reliability and recalls reverberate throughout a company and even industries as discussed in the article.

Although computational simulation is not as wide spread in the medical device industry, the FDA would like to move the community in that direction. The FDA has hosted meetings on computational modeling (http://www.fda.gov/MedicalDevices/NewsEvents/WorkshopsConferences/ucm346375.htm). At the last meeting, a featured speaker from NASA discussed how NASA requires probabilistic computational analysis as standard practice, this stemming from their very public failures. The FDA is also sponsoring the first annual conference on Frontiers in Medical Devices to focus on computational modeling (http://www.asmeconferences.org/FMD2013/).

The US Air Force, Navy, Army and NASA are taking this concept a step further in developing an airframe “Digital Twin”. This is a digital representation of an individual airframe (by tail number). This includes all of the engineering orders, repairs and missions that make each tail number unique. Uncertainty and errors associated with the manufacture, assembly, usage, record keeping and the computational models is all considered to “bound the uncertainty” on the health of the airframe. There could be a corollary to a future “Digital Patient”. The patents history, genetics, life style could used to create a model to simulate the risk of “failure” of a procedure or device.

Simulation-based design analysis is fundamentally about making decisions with uncertainty. The computational methods we advocate are for predicting reliability and managing uncertainty. VLM is a computational methodology that estimates the sensitivity of uncertainty in input variables and the sensitivity of modeling approximations to the final output. In the current age of large multidisciplinary virtual simulation, this is useful in determining how to optimize for the best use of computational and testing resources to arrive at most robust predictions of device reliability. As an example, with regards to implantable medical devices, one wants a high statistical confidence that the device is reliable before beginning patient trials. Too few samples are tested at a limited number of conditions to identify the subtle design issues that affect the reliability of the device once it is put into the market. This is understandable; one simply cannot test enough samples at enough conditions to cover all possibilities. It is also true that one cannot substitute modeling for testing, quality control or good engineering. However, computational models should be an addition tool in the engineer’s toolbox to drive up reliability and decrease the chance of a recall in the medical device industry.

Author:  Dr. Animesh Dey, VEXTEC Chief Product Development Officer

VEXTEC to Present at Inaugural Frontiers in Medical Devices Conference

 

Presenting at ASME's Frontiers in Medical Devices: Applications of Computer Modeling and Simulation Conference

Presenting at ASME’s Frontiers in Medical Devices: Applications of Computer Modeling and Simulation Conference

 

August, 20, 2013-VEXTEC ‘s Chief Technology Officer, Dr. Robert Tryon, and Dr. Animesh Dey, VEXTEC’s Chief Product Development Officer, will be making three presentations at the American Society of Mechanical Engineers (ASME) First Annual Conference on Frontiers in Medical Devices: Applications of Computer Modeling and Simulation, in Washington, D.C. September 11-13, 2013.

Dr. Tryon, who has spoken at previous medical device conferences, will discuss the use of VEXTEC Virtual Life Management®(VLM) simulation software in determining and improving product reliability. The presentation entitled “Computational Models to Predict the Structural Reliability of Aerospace Systems” will detail three VLM cases from the aerospace industry, which has a similar risk profile to the medical device market.  These examples involve a helicopter turbine wheel, an aircraft engine fan blade, and an auxiliary power unit of a commercial airliner.

The second presentation reflects a technical collaboration with Boston Scientific Corporation, Inc. The presentation, “Using Probabilistic Computational Durability Modeling and Simulation to Create a Virtual Design of Experiments Based on Limited Laboratory Tests”, will be presented by Dr. Sanjeev Kulkarni, R&D Fellow at Boston Scientific. Dr. Kulkarni participated in the collaborative program and applied the results to BSCI products. The presentation covers the use of VLM computational models to accurately simulate statistically large populations of medical devices.

The third VEXTEC presentation will be given by Dr. Animesh Dey who is a recognized expert in the field of Uncertainty Management. Dr. Dey’s presentation entitled “Confidence Estimates Due to Uncertainty in Multi-Disciplinary Computational Analysis”, details methods to propagate and manage the uncertainty in the computational models themselves as well as the data and information used as input into the models.

About VEXTEC:

VEXTEC is a computational simulation company that provides computer aided engineering services and technical expertise in the areas of product development and in-service reliability.  The Virtual Life Management® (VLM) engineering software platform helps companies accelerate product development, reduce physical testing and speed time to market for new products, and resolve in-service product performance and reliability issues related to cyclic fatigue, wear and corrosion. VLM simulations explain why, how, when and where product damage will occur and what can be done to mitigate the situation and improve product reliability.