Sun, 2012-12-02 15:26 | 
Περιγραφή Διατριβής:
Textiles are used in many cases in human’s everyday life. The main usage is twofold: firstly, is aesthetics in order to improve the image of the people and secondly the functionality which have to do with the protection from weather conditions like cold, rain, sun, ultraviolet radiation, etc.
Fabrics attract a lot of attention from researchers all over the world due to production low cost, low weight to strength ratio and generally the extraordinary mechanical properties they exhibit. Textile structural components are commonly used in industry and in many advanced technological applications. Characteristic examples are airbags and seat belts in automotive industry, parachutes and bulletproof wests in the army, ropes and tents in commercial industry, etc. All these applications can be improved and optimized by using effective modeling techniques for the fabrics. Fabric modeling is an elegant task due to high complexity of the structure. High complexity is due to the weaving process and the various modes of deformation. Even though a lot of attempts, from a great number of researchers, have been made there is no reliable and sufficient model for predicting the mechanical behavior of fabrics till today. So, the first target of the present study is to formulate a model adequate to predict and simulate the mechanical behavior of fabrics in a sufficient and reliable way.
The main characteristic of the fabrics is the weave between the warps and the yarns. Weave depicts transparently the material’s microstructure. Locally, the yarns translate, twist and bend independently each other so size effects are inevitable present. The macroscopic fabric response is influenced very much from the microstructure. Classical continuum mechanics theories cannot take into account such size effect phenomena and the usage of a generalized continuum theory is necessary. Cosserat theory falls to this category and in this sense it was used it in the present study.
Beyond the mechanical properties fabrics exhibit many functional advantages. Their structure facilitates the integration with electronic systems, like microprocessors, micro sensors, etc.
