ECCM16 - 16 TH EUROPEAN CONFERENCE ON COMPOSITE MATERIALS, Seville, Spain, 22-26 June 2014 1 THE WORLD-WIDE FAILURE EXERCISES: HOW CAN COMPOSITES DESIGN AND MANUFACTURE COMMUNITIES BUILD THEIR STRENGTH A S Kaddour a* , M J Hinton b , S Li c and P A Smith d a QinetiQ, Farnborough, Hampshire, GU14 0LX, UK b National Composites Centre (NCC), Bristol, BS16 7FS, UK c Aerospace Technology Centre, Nottingham University, NG8 1BB, UK. d Faculty of Engineering & Physical Sciences, University of Surrey, Guildford, GU2 7XH, UK *askaddour@qinetiq.com Keywords: Failure criteria, world-wide failure exercise (WWFE), triaxial stresses, damage modelling.  QinetiQ Ltd 2014 Abstract In a manner reminiscent to establishing the ‘periodic table’, researchers and keen material scientists/engineers have been engaged in intensive activities trying to identify their own characteristic model or discover a unique aspect/failure mode in a composites material. No tangible progress could have possibly been achieved without the relentless efforts made by some 40 dedicated developers of advanced methods for failure criteria for composites. They have been at the core of an international initiative, referred to as the World-Wide Failure Exercise (WWFE). It is aimed at establishing the maturity of existing method and the remaining challenges of building the best method to accurately predict the strength of composites materials. The paper deals generally with the three exercise (WWFE, WWFE-II and WFE-III) which have been conducted over the last 20 years. The focus is on some of the lessons emanating from the latest exercise (WWFE-III). 1 Introduction Despite the heavy use of composites in leading industries (aircraft, automobile, wind turbines, ships), composite design and manufacture communities are, nonetheless, still facing numerous and real challenges. These challenges include (a) shorter life cycles (b) automated manufacture (c) production of high volumes (d) integrating 3D structures into 3D architectures (e) development of alternative materials and (f) meeting climate change targets. For instance, it is anticipated that meeting CO2 emission reduction targets will drive toward lighter transports. ACARE (The Advisory Council for Aeronautics Research in Europe) calls for a 50% reduction in CO2 emissions by 2020 versus 2000. To meet these targets, it is estimated that 200kg will be taken out of the medium size cars (family cars) by 2020 and further 200 kg by 2030. These challenges are becoming harder to meet due to the continuous lack of validated simulation tools/ standards. Reliable tools capable of predicting the linear and nonlinear behaviour, including manufacturing, damage and failure, are at the heart of those challenges.