Research On The Virtual Technique Of Tower Crane Jib

National standard regulates that there must be a series of inspection and test after the manufactured and major accident repaired of tower crane.In the test of tower crane jib,the command methods is inspector according to the principle of materials mechanics to design and check the structure of tower crane by the meaning of allowable stress and take the stress detecting instrument in the construction site for testing.However,the former method is by the limitation of the workload,check several sections which is considered dangerous in theory;the latter method in stress test of the main component used by the electric resistance strain gauges at present,however this method not only easily influenced by environmental factors,but also in the process of operation the workers need to paste the strain gauges and connect the thread in the structure of the dozens of meters with great labor intensity and the problem of personal safety.In recent years,along with the popularization of computer technology and the enhancement of calculation speed,finite element analysis is getting more widely attention in engineering design and calculation,becoming the effective solution to solve the problem of complex engineering analysis.Using the computer technology and finite element structure calculation technology to study on the technology of virtual test to replace the manual detection and solve the problem of labor intensity and the risk in the work.The virtual test technique of tower crane jib can replace the actual stress test to obtain the stress data.It includes the advantages as follows:saving human and material resources to avoid the waste of resources in the process of the actual stress test as well as the influence of environmental factors;because of the operation is simple and fast,it is suitable for the use of general and professional;the more comprehensive and detailed results is not only restricted to the check point in the type test which is summarized by the test experience,but also the force condition of the whole crane jib is clearly showed up by the way of the combination of the cloud pictures and data results to fully understand and master the stress of crane jib.The so-called "virtual" refers to use technology to achieve the imitation material object or the pseudo material object through some kind of technology to turn a physical entity into some logical counterparts.Physical entity is real,that actually exists;and virtual realization is fictive,that is sensuous to the users.Accordingly.the technology which is used to implement the virtual called virtual technology.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.