Establishment Of Low Cycle Stress Soft Sensor Model For Truck Mounted Concrete Pump And Its Application In Fatigue Damage Calculation

Truck mounted concrete pump is one of the highest technology content, maintenance of the most difficult, the most expensive complex equipment in construction machinery, and is widely used in roads, bridges, buildings and other construction process because of its flexibility, high efficiency, high degree of automation and excellent maneuverability. Boom structure is an important component of truck mounted concrete pump, and its reliability and safety is the embodiment of competitiveness of truck mounted concrete pump to some degree. Truck mounted concrete pump boom is easily damaged and its force state is complex. But at present, because damage judgment is still based on visual inspection and maintenance arrangement is also depend on experience and lack of scientific basis, malfunction causes damage to the equipment, seriously affecting economic development and social stability. So it has a very important significance in health assessment, predictive failure analysis and maintenance arrangement to health monitoring for truck mounted concrete pump boom.Firstly, the general situation of truck mounted concrete pump and research status of health monitoring for truck mounted concrete pump boom are introduced. It is very hard to carry out health monitoring program because truck mounted concrete pump boom is similar to mechanical arm, very long and has frequent actions. Structural features and load characteristics of truck mounted concrete pump boom are introduced and analyzed in detail. It has mapping relationship between angles of truck mounted concrete pump boom and low cycle stress that can reflect its stress level, which provides the feasibility for soft sensor applied to health monitoring for truck mounted concrete pump boom.Secondly, for the research object, truck mounted concrete pump boom system with long37meters and four-bar, angles of boom are selected as the secondary variables, low cycle stress as the primary variable to build soft sensor model. Through structure failure statistics and analysis of truck mounted concrete pump boom, it indicates that fatigue damage is the main engineering damage. Thirdly, because low cycle stress can mainly reflect boom’s stress level and fatigue damage that it causes indicate the actual damage of truck mounted concrete pump boom to a certain extent, the health monitoring program which is based on soft sensor is designed. On the basis of acquisition of angle signal, the program get low cycle stress, and calculates fatigue accumulating damage until provides health assessment of truck mounted concrete pump boom. Moreover, the technical route of getting fatigue damage parameter is work out.Finally, the validity of the model of soft sensor and the feasibility in engineering application which health monitoring program is based on soft sensor are checked by engineering test. The result indicates that soft sensor is an effective way to get the stress of truck mounted concrete pump boom. It is a suitable health monitoring program of truck mounted concrete pump boom to monitor low cycle stress of boom and regard fatigue accumulating damage as health evaluation criterion.