Vibrations of a beam with a unilateral spring. Periodic solutions - Nonlinear normal modes

摘要: The thesis consists of two parts presented in four chapters. first one deals with the modelling, simulations and experimental validations a beam model unilateral linear spring under periodic excitation. It is simplified mechanical satellite solar array an elastic bumper during launch stage. system harmonic excitation given as imposed acceleration or punctual force. validated sequences on aluminum contact Solithane bumper. results show good agreement numerical simulations. second part focused nonlinear normal modes systems. A new formulation then to find these zeros mapping. An algorithm based continuation solutions performed using existent algorithms. perturbation technique multiple scales method for calculation approximate analytical differential equation term introduced. We use this n degrees freedom autonomous contact. also deal case forced systems, thus we obtain simple procedure modes. All techniques provide different mathematical tools modal analysis treated thesis.