Research On The Numerical Methods For Sheave Platform Beam Of Box-section Steel Derrick

Sheave platform beam is the key force component of steel derrick. At present, numerical calculations of steel derrick sheave platform beams are assumed to be ordinary beam elements. In recent years, the application of box-section steel derrick is increasing. The high span ratio of box-section sheave platform beams is relatively small, mechanical properties are different from ordinary beam. Assumed to be beam element for the numerical calculation is no longer accurate. Therefore, in the study of box-section steel derrick, it is a very important work to accurately summarize the force distribution of sheave platform beams and to find a reliable numerical method.This paper takes sheave platform beams of box-section steel derrick as research objects. Firstly, the bearing performance and the law of stress distribution of sheave platform beams under progressively load are studied by similar model experiment. The result shows that sheave platform beams of box-section steel derrick do not meet the law of ordinary beam which has uniform stress and has maximum stress at the bottom of mid-span. Therefore, assuming sheave platform beams as beam elements is not a correct method when doing numerical calculation. Under the condition of regular raise load and rope-broken load, the stress of box-section steel derrick is lower than the yield strength of Q235, which satisfies the bearing capacity requirement.Secondly, the results of similar model experiment are compared with the results of numerical simulation by using shell element of finite element software, ANSYS. The results show that the data of similar model experiment is basically coincided with the data of numerical simulation. The deviation is around 5 percent. Considering of the deviation of similar model experiment and the calculation parameters, the two methods can verify with each other. Therefore, it is a reliable method of using shell element to simulate sheave platform beams of box-section steel derrick.Ultimately, taking the box-section steel derrick in active service at a mining area as engineering background, the stress of box-section steel derrick was tested in field. The testing results are coincided with the data of numerical simulation. The results of field test and the numerical simulation can verify each other, which further confirmed that the method of numerical simulation above-mentioned is reliable.