Software predicts fatigue in welded structures

Edited by the Engineeringtalk editorial team Oct 3, 2005

A ground-breaking new method for predicting fatigue life in welded structures could revolutionise the field and has the potential to save billions of dollars.

A Battelle researcher in the USA has developed a ground-breaking method for predicting fatigue life in welded structures that could revolutionise the field and has the potential to save billions of dollars in the aerospace, automotive, bridge construction, shipbuilding, pipeline and offshore oil rig industries.

Battelle's ground-breaking technology, trademarked Verity, will soon be available worldwide as a result of an agreement reached with UK company, Safe Technology.

Modelling and testing regulations vary from industry to industry, but it's safe to say billions of dollars are spent every year on testing, modelling, and predicting the fatigue life of welded structures.

Pingsha Dong, Technical Director of the Center for Welded Structures Research at Battelle, has developed a method that can eliminate the need for expensive testing and overengineering that is done to compensate for uncertainties (usually dubbed the "fudge factor") in current fatigue design practices in various industries.

"For the past 25 years, experts in the field have been trying to address the inadequacies in stress analysis for fatigue design of welded structures so that companies would not have to compensate for poorly correlated test data", says Pingsha.

"Eventually, the industry and academia gave up".

"We did not".

"This is a robust, consistent methodology".

"No matter who uses it, you get the same answer".

"No matter what load you apply and no matter what geometry you have, the mesh-insensitive model gives you a very accurate way of determining the fatigue life of a weld", said Ford's Senior Technical Specialist Dr Hari Agrawal, a well-known fatigue design expert in the automotive industry.

Verity will be included as a module within the Safe Technology product marketed as fe-safe.

The worldwide distribution agreement between Battelle and Safe Technology marks the first widespread commercial introduction of Battelle's patented Verity methodology, which predicts the fatigue life of welded structures with unprecedented accuracy.

"We are thrilled to team with Safe Technology in making Verity available to users around the world", said Battelle's Pingsha Dong who developed Verity.

Industry experts estimate that the demonstrated effectiveness of Verity should save hundreds of millions - if not billions - of dollars in engineering, testing, and manufacturing costs.

The fe-safe suite of durability analysis software has become the tool of choice selected by leading companies worldwide for the analysis of machined, forged and cast components in steel, aluminum and cast iron, and for complex assemblies, high-temperature components, welded fabrications and stamped components.

"The Verity method offers major advantages in terms of accuracy and ease of use", said John Draper, Safe Technology's CEO.

"Until now, Verity has only been available through specific arrangements between Battelle and its clients".

"We are delighted to be working with Battelle to make it available worldwide in a user-friendly format".

"The Verity software will be released in fe-safe in February".

In the USA, Verity was used to win a recent Society of Automotive Engineers (SAE) fatigue design and evaluation committee weld challenge against some of the top minds in fatigue life prediction.

Recently, one major automotive company began using the method for full-vehicle durability prediction and has seen considerable savings in new-vehicle development cost.

Recognising the enormous impact of Verity tools in the automotive industry, SAE International awarded Pingsha and his team the prestigious Henry Ford II Distinguished Award for Excellence in Automotive Engineering.

Safe Technology has organised training sessions by Pingsha Dong: "Verity mesh-insensitive structural stress method for fatigue evaluation of welded structures", in Michigan and Texas during November 2005.