A Historical Perspective on Varestraint Testing and the Importance of Testing Parameters

Book chapter, 2016

This paper provides a historical perspective on the development of the Varestraint testing method as well as the design of a new Varestraint testing machine, utilized on a daily basis in the aerospace industry to solve hot cracking issues in production. The paper also discloses the importance in choosing the right testing parameters in order to minimize scatter in test results and to be able to make a reliable judgment in susceptibility towards hot cracking. Weld current, weld speed, bending rate and strain level as well as the evaluation procedure with i.e. measurement errors are included in the analyses.