Study On The Design Principle Of Crawler Crane's Pseudo-characteristic Curve

Boilers play an important role in the national economy construction, and the jib metal structure is one kind of the important load-carrying components of crawler crane. Its mechanical properties have directly influence on the whole machine's running. However, now jib designing is also mostly manual work done by the designer's experience, with reference to representative projects, which is simply studied out and perfected, lacking theory basis.According to the present situation, the author puts forward the concept of crawler crane's pseudo-characteristic curve taking a practical engineering project as reference. Crawler crane's pseudo-characteristic curve differs from the lifting characteristic curve. It is the the lifting characteristic curve only considers the jib's structure without considering crawler crane's whole structure during concept design phase. It is the foundation of detailed design and has guiding significance of manipulator design.Crawler crane's pseudo-characteristic curve's design bases on the three known parameters-maximum lifting load, the basic arm length and the max length of the boom. From the point of view of principle design, having maximum lifting load and the basic arm length as known parameters, based on GB/T3811-2005 and stiffness requirement, strength condition stability condition as design criteria, the author determines functional relationship between the known parameters and the height of the basic jib, the width of the jib, the main chord's sectional area, internode length and the web member's sectional area. Based on the primary design of the basic jib, the author determines the relevant structure parameters of the standard mast section. After the preliminary design of the jib, the author determines the pseudo-characteristic curve and the load diagram of the basic jib based on structuring principle of equalizing stress and constant moment.Based on the analysis and research above, the author designs the system of crawler crane's pseudo-characteristic curve using software developed method of object oriented-Visual Basic 2005 and connecting with Matlab 7.1 and Access database. Actual examination QUY630 crawler crane shows that, this software well meets the technical requirements of crawler crane design and has certain practical value.