Research On Optimization Of NNIA Configuration Algorithm Based On CNT Yarn Senso

The three-dimensional braided composites have gradually become excellent structural building materials in frontier fields such as aerospace and military ships due to their low density,low quality,excellent heat resistance and low expansion deformation.However,due to the particularity of related environment,3D braided composite parts will be affected by high temperature,high pressure,corrosion and other factors in use,which will lead to structural damage of parts and adverse effects.Therefore,it is necessary to use the structural health detection sensor to realize the realtime intelligent detection of the structural health of 3D braided composites.Carbon nanotube yarn sensor has the characteristics of small volume and excellent electromechanical performance.It is an excellent structural health monitoring sensor.In this paper,the optimal configuration of CNT yarn sensors in the process of health detection of 3D braided composite smart structures is studied.Firstly,the performance and embedding method of CNT yarn sensor are studied.In this paper,the CNT yarn sensor and textile yarn are woven together by four-step three-dimensional six-direction weaving process,and the CNT yarn sensor is embedded effectively in the part.At the same time,the performance of embedded sensor is analyzed to provide data support for the subsequent optimization algorithm of CNT yarn sensor.Subsequently,the paper studies the construction of sensor optimal configuration algorithm.Because the optimal configuration scheme of CNT yarn sensor is a typical multi-objective optimization problem,the optimization algorithm of CNT yarn sensor is built on the basis of the non-dominant nearest neighbor immune algorithm based on multi-objective optimization,and the maximum number of sensors embedded in the axial and weft directions of the part and the effective coverage rate of the sensors are the constraints.Then,the region selection mechanism is introduced to optimize the algorithm solution process,so as to reduce the error between the actual effective coverage rate and the theoretical effective coverage rate of the configuration scheme given by the algorithm,and lay the corresponding theoretical foundation for the optimal configuration scheme of CNT yarn sensor.Finally,the damage measurement experiment of lossy parts and the tensile experiment of nondestructive parts are carried out,and the effectiveness of the algorithm is studied and analyzed based on the experimental data.The experimental data show that the sensor network constructed according to the configuration scheme given by the algorithm can effectively realize the real-time monitoring of 3D braided composite parts and effectively reflect all kinds of damages inside the parts,and at the same time,it can complete the location of the damage source,and the measurement error is less than 1mm.It is proved that the optimal configuration algorithm of CNT yarn sensor is effective in the process of health monitoring of 3D braided composite intelligent structure.