This project belongs to the basic field of public welfare technology. At present, the number of elevators in use in my country has reached 6.28 million, and elevators are closely related to people's daily production and life. In recent years, elevator accidents/incidents have occurred from time to time, often causing serious personal injuries and adverse social impacts. Their safety and reliability cannot fully meet the people's expectations for safe and convenient travel. Design and manufacturing defects and extended service of elevator components are one of the important reasons leading to elevator accidents/incidents. Their safety risks have gradually attracted great attention from all parties in society. The former General Administration of Quality Supervision, Inspection and Quarantine attached great importance to the prevention, control and scrapping of elevator components: Special actions have been carried out for quality inspections of elevator components on many occasions to promote the improvement of elevator quality; a special letter recommends that SAC/TC196 develop scrapping standards to resolve the problem of extended service of elevator components. Strengthening the prevention, control and scrapping of elevator components safety risks is an urgent issue to solve major livelihood concerns for elevator safety and promote the healthy development of the industry. This project comprehensively uses multi-disciplinary knowledge such as mechanics, materials, and information to overcome technical problems such as complex elevator systems, vibration of wire ropes and difficulties in elastic-plastic modeling of large size thin plates. Systematic and in-depth research has been carried out on key technologies for risk prevention, control and scrapping of elevator components. The main results are as follows: 1. Completed failure analysis and identification of main elevator components and their risks, and established a complete failure mode and risk database; 2. In-depth theoretical analysis and experimental verification were carried out on the failure evolution of brakes, wire ropes, landing doors and other components;3. Two sets of new intelligent testing equipment were developed, which achieved accurate and rapid detection of key parameters of speed limiters and brakes;4. Risk prevention and control methods and technical conditions for scrapping of elevator components were proposed, and a series of national and local standards were formed. He took the lead in drafting 5 national standards and 2 local standards including GB/T 24803 and GB/T 31821, published 25 papers (9 SCI/EI), authorized 16 patents (2 invention patents), and 2 software copyrights. The scientific and technological novelty search of the Chinese Academy of Sciences shows that the comprehensive technology of this project has reached the international advanced level. The research results have achieved great social value. GB/T 31821 is the first in my country. It has made up for the gaps in domestic and foreign technical standards, effectively resolved social conflicts, accelerated the renovation and renovation of old elevators, and played a role in the annual decline of elevator accidents in my country. important role. Some of its provisions are quoted by five mandatory safety technical specifications such as TSG T7001, and have been forcibly applied to the supervision and inspection of elevators nationwide. The basic database and risk assessment methods built by GB/T 31821 and GB/T 24803 provide useful reference for elevator design and manufacturing, and also lay a solid foundation for the national key R & D plan under study for elevator accident prediction and prevention based on big data. The research results have also achieved great economic value and are an important technical basis for the implementation of the Shanghai City Government's practical project ldquo; Old Elevator Safety Assessment rdquo;. In the past three years, the Municipal Special Inspection Institute has completed safety assessments of 4851 old elevators, adding new inspection revenue of more than 24 million yuan; through the application of the results of this project, manufacturing companies have optimized product design, improved product quality and market competitiveness. In the past three years, Schindler (China) has produced and sold more than 110,000 elevators, with an output value of more than 26 billion yuan and paid taxes of more than 1.5 billion yuan. Shanghai Sanrong exported more than 4000 elevators and earned foreign exchange exceeding 200 million US dollars. The results have also promoted the renovation and repair of elevators. In the past three years, Shanghai has completed the renovation and overhaul of 4288 elevators. Shanghai Xinshida alone has completed the renovation and overhaul of more than 800 elevators, achieving a turnover of more than 42 million yuan and a profit of more than 4 million yuan. By scrapping and replacing the main components, the safe operation of the elevator is ensured, and unnecessary scrapping of the whole machine can also be avoided, saving users a lot of money.