{"product_id":"damage-tolerance-investigations-of-innovative-metallic-airframe-structures-von-sascha-hausler","title":"Damage tolerance investigations of innovative metallic airframe structures","description":"\u003cp\u003eThe continuously expanding commercial air traffic of the last decades steadily increased\u003c\/p\u003e\u003cp\u003ethe demand for highly efficient aircraft which offer extended operation times\u003c\/p\u003e\u003cp\u003ewhile reducing costs and environmental impact at the same time. The associated design\u003c\/p\u003e\u003cp\u003erequirements for reduced structural weight and improved fatigue life represent\u003c\/p\u003e\u003cp\u003ethe major challenges for todays aircraft structures and have significantly intensified\u003c\/p\u003e\u003cp\u003ethe competition between metallic and composite airframe applications. New metallic\u003c\/p\u003e\u003cp\u003edesign concepts try to face this competition by combining latest materials and\u003c\/p\u003e\u003cp\u003einnovative manufacturing methods, like high speed machining, laser beam welding\u003c\/p\u003e\u003cp\u003eor friction stir welding, which allows for possible savings with respect to structural\u003c\/p\u003e\u003cp\u003eweight and manufacturing costs. However, due to their integral characteristics, the\u003c\/p\u003e\u003cp\u003edamage tolerance behaviour of these new designs is generally inferior to the common\u003c\/p\u003e\u003cp\u003edifferential design. Reliable estimations on the fatigue life of integrally stiffened\u003c\/p\u003e\u003cp\u003estructures consequently necessitate assessment methodologies that are capable to include\u003c\/p\u003e\u003cp\u003eadditional manufacturing influences and offer numerical efficiency in order to\u003c\/p\u003e\u003cp\u003ebe practical for parametric studies during airframe design.\u003c\/p\u003e\u003cp\u003eTherefore, the development and enhancement of simulation methods for efficient and\u003c\/p\u003e\u003cp\u003ereliable evaluation of cracks and crack growth represents the main objective of this\u003c\/p\u003e\u003cp\u003ethesis. Two simulation methods are implemented and investigated for this purpose,\u003c\/p\u003e\u003cp\u003ethat are based on different approaches and intended for distinct applications. One\u003c\/p\u003e\u003cp\u003emethod is based on analytical stress function expressions and enables a very efficient\u003c\/p\u003e\u003cp\u003eevaluation of the complete fatigue crack growth life of cracked airframe structures.\u003c\/p\u003e\u003cp\u003eThe proposed approach in this context is generally based on plane assumptions and\u003c\/p\u003e\u003cp\u003elimited to pure mode I crack loading. In order to be able to additionally consider\u003c\/p\u003e\u003cp\u003ecrack turning under mixed mode loading, a second simulation method is presented\u003c\/p\u003e\u003cp\u003ewhich implements an extended finite element framework for a mesh independent\u003c\/p\u003e\u003cp\u003erepresentation of cracks in two dimensions. The additional combination with the\u003c\/p\u003e\u003cp\u003ematerial force concept, as alternative crack state parameter, allows for automated\u003c\/p\u003e\u003cp\u003esimulations of crack growth under mixed mode loading without any need for remeshing\u003c\/p\u003e\u003cp\u003eoperations.\u003c\/p\u003e\u003cp\u003eBoth simulation methods are validated based on different crack configurations and\u003c\/p\u003e\u003cp\u003eare applied for crack growth investigations of varying configurations of integrally\u003c\/p\u003e\u003cp\u003estiffened panels under pure mode I and mixed mode loading conditions. In this\u003c\/p\u003e\u003cp\u003econtext, a special focus is set on the influences of additional internal stresses that\u003c\/p\u003e\u003cp\u003efollow either from the applied manufacturing processes or an intentional prestressing\u003c\/p\u003e\u003cp\u003eof the stiffeners. Despite the general limitation to plane considerations, the proposed\u003c\/p\u003e\u003cp\u003emethods show a good accordance with experimental, theoretical and alternative\u003c\/p\u003e\u003cp\u003enumerical results. This demonstrates their capabilities to simulate fatigue crack\u003c\/p\u003e\u003cp\u003egrowth and crack turning in integrally stiffened airframe structures and motivates\u003c\/p\u003e\u003cp\u003efurther research with respect to a possible extension to three-dimensional problems.\u003c\/p\u003e\u003cdiv class=\"aw-variant-hidden-subtitle-div\" id=\"aw-variant-subtitle-9783869557748\"\u003e\u003ch3\u003e\u003c\/h3\u003e\u003c\/div\u003e","brand":"Libri","offers":[{"title":"Softcover - 9783869557748","offer_id":39463129481309,"sku":"9783869557748","price":45.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0940\/0622\/files\/ed85e097-b93d-4d68-9c84-4f56b06febe5.jpg?v=1780465207","url":"https:\/\/shop.autorenwelt.de\/products\/damage-tolerance-investigations-of-innovative-metallic-airframe-structures-von-sascha-hausler","provider":"Autorenwelt Shop","version":"1.0","type":"link"}