Research on Failure Criterion of Lattice Jib Structural System Reliability

In Four-column limb lattice jib structure system as the research object, considering the structure and mechanical characteristics, combining with the allowable stress method, from the failure mode of static strength, stiffness, overall stability and local stability to build lattice jib structure system reliability failure criterion. Based on the influence of parameter perturbation calculation of four-column limb lattice jib structure system, get the length of the jib, lifting weight, jib elevation, hoisting load bearing point offset, the proportion of wind environment on the influence of different failure modes and failure change law, as the main failure mode of the decision to provide the basis and methods.

Dynamic Response Analysis of Super-Long Hybrid Jib Structure under Impact Load

For the vibration of the super-long hybrid jib structure of hundreds of meters level elevating platform fire truck under water cannon impact load, linear dynamic response and nonlinear dynamic response methods were used to analyze the characteristics of the structure in the conditions of the large deformation of the structure, geometry, contact, material nonlinear and coupling. Through analyzing linear and nonlinear dynamic response results about peaks, steady-state values, amplitudes and dynamic load coefficients, the more scientific and practical method was given. The results provide scientific data for active vibration control and track control, and lay the foundation for achieving stable-work and pinpoint of the elevating platform. The results shows that dynamic load coefficients of each part of the super-long hybrid jib structure are not identical. The dynamic load coefficient of where lifting load is smaller and support part is larger. The larger gap between linear and nonlinear dynamic response results shows that linear dynamic response analysis should be taken as an estimation method, but nonlinear response analysis is more scientific and applied.

Research on the Virtual Test Technique of Tower Crane Jib

With the development of construction technology, the increasingly high performance requirements for tower crane, its technical performance, strength and longevity is particularly important. The metal structure is an important part of the tower crane, which bears the dead weight of the tower crane and a variety of the work of external loads. Strength, stiffness and stability are used to ensure safe and reliable work of the tower crane; otherwise, major accident may happen. With the tower crane to the development of large, heavy load and ultra-high, the test of the structure is particularly important. The research on the virtual test technique of tower crane jib in this paper bases on the characteristic parameter extraction of the jib structure, using the parameterized APDL programming language of finite element software ANSYS to do statics analysis by model building, and complete the virtual text of the jib. Finally obtain the corresponding results data of the actual test inspection and the location as well as the virtual test value of the most dangerous point, to determine the safe reliability of the jib structure and the rationality of material use.