Safety Assessment And Software Development Of Box Girder Structure Of Bridge And Portal Crane

Crane metal structure is a large welding structure.Defects(such as cracks)inevitably produce in the process of production,assembly and operation.These defects have hidden dangers for the safe use of cranes in service.During the service period of crane,once the crack propagates to failure fracture,it maybe lead to unpredictable accidents.Considering the safety of crane in service,it is of practical significance to assess the safety of crane with defects.The paper analyses and establishes the safety assessment method and process of crane box girder structure,and develops safety assessment software,which is of theoretical significance and application value to the safety assessment of crane structure with defects.By analyzing the evaluation criteria of structural integrity such as R6,BS 7910:2013,API 579 and GB/T19624-2004,and combining with the characteristics of box girder structure of service crane,the safety assessment process is established.By writing the software framework suitable for crane structure safety assessment,analyzing the key technology in software development,develops the software of crane box girder structure,and provides theoretical basis and technical supports for the development of complete and reliable crane structure safety assessment software.The main work of this paper is as follows:(1)The failure modes and defect types of crane box girder structure are analyzed.Based on R6,BS 7910,elastic-plastic fracture theory and reliability theory,the safety assessment methods and process of crane structure are studied and established,and the probabilistic safety assessment method based on J integral is explored.(2)According to the safety assessment method and process of crane box girder structure,the software architecture of crane structure safety assessment is developed.The function module of the software is designed,the feasibility study is carried out,and the data flow diagram and structure block diagram are established.Analyze the logical relationship between modules and build the logical relationship diagram.(3)Combined with the safety assessment process of crane box girder structure,the secondary development technology of ANSYS is studied,and the interaction with finite element analysis software(ANSYS)is realized,and the interface method of calling ANSYS is determined.(4)Analyze the processing technology of engineering data in software development.Analyze the characteristics of XML storage engineering data,study the method of using XML storage data in QT development platform,and explore the method of generating APDL command stream files.(5)Combined with the safety assessment process and software architecture of gantry crane,the fracture assessment software is developed,and the fracture assessment process is encapsulated in Hcrane module.The command flow files of the whole model and sub-model of gantry crane are compiled.The failure assessment(FAD)diagram is drawn by using QCustomPlot module.The coordinate points of the calculated load ratio and fracture ratio are drawn to the failure assessment diagram to determine the safety of the structure and output the assessment report.