A Compressive Sensing Method for Multi-source Shock Load Identification of Mechanical Structures

Abstract

The present invention relates to a compressed sensing method for multi-source impact load identification of a mechanical structure for solving ill-posed natures of the multi-source impact load identification inverse problem of a highly underdetermined system. The method comprises the following steps of (1) measuring a frequency response function between an action point of impact load of the mechanical structure and a response point of the mechanical structure, and furthermore constructing a sensing matrix; (2) measuring signals generated by dynamic load of the structure by using a sensor; (3) constructing an underdetermined equation of the multi-source impact load identification; (4) constructing an L1-norm-based compressed sensing convex optimization model of the multi-source impact load identification; and (5) solving the compressed sensing optimization model by using a two-step iteration threshold algorithm, and obtaining a compressed sensing solution of multi-source impact load. Time and space combined sparsity of the impact load is fully utilized, the method is suitable for identifying and positioning the multi-source impact load acting on the mechanical structure, and the choke point that the underdetermined system cannot be solved by a traditional regularization method based on L2 norm is overcome.

Description

technical field [0001] The invention belongs to the field of state monitoring of mechanical systems, and in particular relates to a compressive sensing method for identifying multi-source impact loads of mechanical structures. Background technique [0002] Impact loads are a very important class of dynamic loads, especially in structural health monitoring of composite materials. For example, fan blades used for wind power generation are inevitably impacted by foreign objects such as wind and sand, flying birds, hail, and maintenance tools during operation and maintenance, and the frequency of occurrence is relatively high. Potential safety hazards caused by the stability and carrying capacity; the sudden airflow acting on the wings of the aircraft, the impact of birds and maintenance tools on the wings. It is very necessary to monitor such shock signals in real time, and it is very difficult to measure them directly. For special dynamic loads such as shock loads, precisely...

AI Technical Summary

Problems solved by technology

This method has obvious defects: (1) the workload is huge, and each assumed position needs to be calculated once by applying the regularization method; (2) the multi-source impact load cannot be identified; (3) the load time history and position identification are separated, and cannot Realize refactoring and positioning at the same time

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