Structural health monitoring technology is a science used to evaluate the severity of structural damage and locate the location of damage. The 13th Five-Year Plan clearly states that a large number of transportation hub projects and control hub projects must be established. With the implementation of these major national strategic projects, structural health monitoring is bound to become a focus in the field of civil engineering. Existing monitoring technology has problems such as huge workload for sensor layout, data redundancy, and lack of effective cumulative fatigue damage assessment mechanism (50ndash;90% of failures in large structures are caused by fatigue damage). The project ldquo; Key technologies of passive wireless strain detection and its application in structural strain monitoring rdquo; applies cutting-edge technologies in the field of microwave engineering to the field of civil engineering, and the results are applied to structures including civil engineering, buildings, roads, bridges, pipelines, vehicles, dams, etc., achieving ldquo; precise strain sensing, rapid data transmission, low cost, and risk prediction rdquo; and other goals. The main innovation points of the project are: 1. Strain sensor multi-physical field coupling and multi-dimensional information fusion technology: A multi-physical coupling model of the mechanical model, electromagnetic model, and mechanical deformation model of the RFID sensor has been established, scientific research on information fusion and processing methods has been carried out, and the physical layer information required for structural health monitoring has been clarified; at the same time, the design has been optimized for indicators such as strain sensitivity, effective monitoring range and sensor miniaturization. The results provide reliable theoretical basis and efficient information processing and monitoring technical solutions for structural health monitoring, and are the core technical support of this project. 2. Micro-mechanism damage pattern recognition technology: Introduce a micro-mechanism damage model based on void growth, which is suitable for monitoring ductile damage of steel. By conducting damage simulation on pseudo-static forces, use the pattern recognition paradigm to describe structural health monitoring problems, and clarify the detection. Fatigue damage degree and damage evolution rule of the structure. It solves the long-standing problem of lack of effective fatigue damage assessment mechanisms in the field of structural health. 3. Topology optimization detection technology for damper residual strain: By optimizing the topology of randomly excited structures with additional dampers, a scheme is proposed to simultaneously obtain the optimal topology of the randomly excited structure and the optimal distribution of discrete dampers, which realizes the measurement of the residual strain of the structure; Multi-point RFID strain sensors are arranged on the detection structure, and performance indicators based on multi-point maximum historical strain and residual strain are used to evaluate damage, giving an efficient information utilization scheme. It solves the problem of optimal sensor layout and data redundancy in practical engineering applications of this project. 4. Road and bridge structure monitoring technology: RFID patch antennas are used as strain sensors and transmission terminals for wireless data transmission without complicated wiring; numerical simulations and tests have been completed to prove that the resonance frequency drift of rectangular patch antennas is related to the antenna length direction. The strain has a linear relationship, and the normalized sensitivity in the UHF band is-0.9972, which is an increase of 20%-60% compared with similar types of research. At present, based on the project results, 22 invention patents have been authorized, 39 utility model patents have been authorized, and 124 high-level academic papers have been published. The results were positively evaluated by Samii, academician of the American Academy of Engineering and Mao Junfa, academician of the China Academy of Sciences, and positively evaluated and promoted by Xue Songtao, a foreign academician of the Japanese Academy of Engineering. The technology of this project is generally at the international advanced level, and the main technologies have reached the international leading level. The results of the project were exhibited at the International Industry Expo; participated in the national key R & D plan of Shanghai Construction Engineering Group; adopted the cooperative transformation method of technical services, which enabled the industrialization of the project technology. The current cooperation transformation income has reached 452.43 million yuan.