This paper focuses on the inverse problem regarding force localization in the case of non punctual impacts occurring on elastic beams. Following the identification approach proposed to solve this problem and which is based on the reciprocity theorem, the impact location characteristics were determined by using Particle Swarm Optimization algorithm. To eliminate numerical trouble due to the trivial solutions appearing in this formulation, the fitness function was customized by introducing a set of weighting coefficients. Four different formulations of the fitness function were considered and their performances with regards to the number of sensors used and their positions were analyzed. This enabled to select the best combination of weighting coefficients to be used in the context of an impact force localization process based on Particle Swarm Optimization technique. Three sensors were found to be required and comparison with Genetic Algorithm has revealed effectiveness of the proposed method in terms of accuracy and computational time.

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dentifying characteristics of a force generated by non punctual impact is performed to better monitor the health of the impacted structure. This can be achieved through using an implemented structural model. For composite beams, the model can be constructed by means of the finite element method. In this work, the impact is assumed to be a uniform distributed pressure and the impact location is known. Reconstructing the force signal is performed by using regularized deconvolution techniques of the Toeplitz like equation giving the answer in terms of strains as function of the input force. Here, the generalized singular value decomposition based method is used in conjunction with truncation filtering. Quality of the reconstructed force is discussed as function of the mesh size and the mode truncation order.

Reconstructing impact forces can improve considerably structural health monitoring as the extent of damage can be better made out. In this work an inverse problem formulation to identify the pressure generated by a non punctual impact is investigated. Considering the case of linear elastic layered composite structures, reconstruction of impact pressure is performed through a finite element model of the structure and impulse response functions between the impact zone and sensors placed at known positions. Assuming that the pressure is uniform, reconstruction is carried out by regularized deconvolution based on generalized singular value decomposition. The infl uence of mesh size, modal truncation and time sampling on the reconstructed pressure is discussed.

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