Characterization and comparison of defects detection limits of three ultrasonic non destructive methods

This work deals with the Liquid Resin Infusion (LRI) process developed within the research program “FUSelage COMPosite” of DAHER SOCATA. This manufacturing process enables the realization of complex composite structures or fuselage elements in a single phase (mono-material), which considerably reduce connections and relative difficulties. The concern here is the investigation of non destructive testing (NDT) methods that can be applied to LRI-structures in order to define their capacities for defect detection, and especially their associated critical defect size. In aviation industry, the AITM standards require the ultrasonic testing as NDT for composite materials. Therefore the aim of this work is to characterize and compare three different and complementary ultrasonic techniques on composite specimens. Such analysis allows to define the NDT application field of each method in term of defect detection

Characterization and comparison of defects detection limits of three ultrasonic non destructive methods

This work deals with the Liquid Resin Infusion (LRI) process developed within the research program “FUSelage COMPosite” of DAHER SOCATA. This manufacturing process enables the realization of complex composite structures or fuselage elements in a single phase (mono-material), which considerably reduce connections and relative difficulties. The concern here is the investigation of non destructive testing (NDT) methods that can be applied to LRI-structures in order to define their capacities for defect detection, and especially their associated critical defect size. In aviation industry, the AITM standards require the ultrasonic testing as NDT for composite materials. Therefore the aim of this work is to characterize and compare three different and complementary ultrasonic techniques on composite specimens. Such analysis allows to define the NDT application field of each method in term of defect detection

A comparison of three wood species (poplar, birch and oak) for crash application

International audienc

Wood and plywood as eco-materials for sustainable mobility: A review

Wood has always been used by man for his means of transport. It is only since the beginning of the 20th century that it has fallen into disuse due to the industrial production of concrete, steel and plastic materials. However, with global warming becoming undeniable, the societal challenge of decarbonizing transport may bring wood back into the spotlight. In this article, after a brief historical review, arguments about its availability and durability in a bio-economic context are put forward. The main mechanical properties of wood and plywood are then reviewed, along with the main factors influencing both their static and dynamic characteristics, the latter being important for the transport sector. Plywood is extensively detailed in this review paper, as it has been widely used in transport applications in the past, and presents potential optimized mechanical characteristics and eco-friendly resource utilization. Some mechanical models are also presented and put into perspective. A brief panorama of wood associations with natural or technical fibre composites is also proposed. Then, selected recent examples show that wood still has its place in naval, automotive, aeronautical, and even space applications. Finally, some conclusions are drawn and numerous research prospects in this vast and resurgent field are put forward

Wood machining with a focus on French research in the last 50 years

International audienceContext: Woodcutting is a very old technology but scientific research is scarce on the subject. In the last 50 years much work on basic mechanisms as well as industrial processes has been done in France. Aims: The specific nature of wood introduces strong differences between wood and metal cutting processes. The paper focuses on French teams' contributions. Results: The basic aspects of the tool–material interaction for different basic modes in woodcutting are highlighted. In primary conversion such as sawing, veneer cutting or green wood chipping, huge progress comes from automation and the possibility of linking the process to log and product quality through new sensors. In secondary processing much has been done on the links between the cutting process, surface qualification and the properties of these surfaces for further processing, such as gluing or coating. Tool wear depends on the cutting process, timber quality, and species. Trade-offs are required in tool technology and coating technologies may improve tool life. Conclusion: A large amount of knowledge and innovation has come from 50 years of worldwide research effort, with France being particularly active in this period. The transfer of skills from metals cutting industry was often a key, but much is needed to move closer to both metal cutting sector and woodcutting skills among craftsmen