Theoretical and Numerical Study of Flexural Cloaking

Aidin Nojavan

• Publisher: Shaker
• Year: 2023
• eBook ISBN: 9783844091496
• Edition: 0

Cloaking is a special case of wave manipulation, where waves are guided around a space by engineering material properties. In the terminology of cloaking, the middle space is called the core, whereas the material matrix around it is called the cloak. With the help of wave guidance and cloaking, our future environment can be shaped in a healthier and more effective way. The term flexural cloaking refers to the cloaking of flexural waves in thin plates.The design of a cloak is an inverse problem, where the required material properties for a desired physical field are searched. The transformation method is one of the few techniques to solve such an inverse problem. In this method, the desired physical field is described with a coordinate transformation. Based on the corresponding spatial distortion, the required material properties for the transformed physical field are calculated. Regarding the great influence of the underlying transformation on the performance of the cloak, the thesis compares two polynomial transformations of order 1 and 2.In this thesis, different aspects of flexural cloaking are investigated theoretically and numerically concerning different parameters, which have not yet been examined thoroughly. This thesis deepens on one hand the investigation of scattering reduction through flexural cloaking; and examines the capability of isolating the core space through flexural cloaking on the other hand, which is mainly disregarded on the literature. In this dissertation, a strong potential is noticed for the cloak to isolate the core, especially at lower frequencies. The frequency dependency of flexural cloaks is another investigated topic in this thesis, which is not discussed explicitly in the literature despite its importance.