Ramamani, Subramanian2024-08-152024-08-1519901990https://hdl.handle.net/1828/19422A versatile form of a spatially curved and twisted ( or helical) finite ele­ment which can model any spatial curve-like structure in terms of helices has been developed. The present formulation can handle static and free vibra­tion problems. The shape functions are based on the solutions of equations governing static equilibrium. The superiority of the element over the existing ones is illustrated through two examples . Later, with a view to developing a non-invasive diagnostic technique for evaluation of implanted artificial heart valves by an analysis of their acoustic signature, the helical element is used to model and analyze the vibration of the struts of a Bjork-Shiley tilting disc valve. The natural frequencies thus determined are compared with the exper­imentally obtained frequencies.101 pagesAvailable to the World Wide WebThesis