Study On Mechanical Behavior Of Composite Adhesive Structure Based On Micro-Nano Sensors

In this paper,carbon nanotube thin film and MXene/ink sensors which were sensitive,were used to study the mechanical properties of the bonded structure of glass fiber reinforced composite under static tension and cyclic loading.Under static tensile state,when the resistance change rate of carbon nanotube thin film sensor integrated in the structure interface layer was about 1.11%-5.89%,the fracture of the bonded structure could be predicted.Under the condition of static tension acting on the interface layer of the bonding structure,it could be found that the layer farther away from the interface layer was more likely to cause damage through the response of carbon nanotube sensors in different layers.During the tensile test,the shear stress in the middle of the interface layer along the fiber direction center line was greater than the edge shear stress,and the shear stress near the two intersecting edge lines on the interface layer of the lap area was greater than that near the two edges on the center line of the lap area.In the case of damage preseted on the fiber direction center line and the vertical fiber direction center line of the interface layer in the bonded structure lap area,the stress distribution in the center of the interfacial layer was more sensitive to the damage along the fiber direction of the interface layer.The shear strength of the bonded structure would be greatly reduced by preseted damage.Under the loading rates of 0.1 mm/min and 1 mm/min,and the cyclic loads of 3 kN(three times),4.5 kN(three times)and 6 kN(three times),the responses of carbon nanotube thin film sensor and mxene/ink micro-nano sensors in different positions of the bonded structure of glass fiber reinforced composite were studied,it could be concluded that the shear stress in the middle of the interface layer was greater than that in the edge.By introducing the residual stress influence parameter(ER),the change of residual stress with the cyclic loading process was analyzed.ER of the four sensors was less than 14%during the second cyclic loading,which indicated that the residual stress in different positions of the bonding structure had been released.