Method for determining weak rods in truss structures of hoisting and conveying machinery

Abstract

The invention provides a method for determining weak rods in truss structures of hoisting and conveying machinery. By judging whether the rods reach critical conditions or not according to practical stress states of the rods, the problem that only part of the rods are checked without regard to bending moments of ends of the pressed rods in the prior art is solved. Practical stresses of all rods are extracted in binary iterative analysis in each time, whether each rod reaches the critical conditions or not is judged, stretch bent rods are judged according to strength theory, pressure bent rods are judged according to stability of the pressure bent rods, and the rods are repeatedly loaded until a certain rod or a certain batch of rods reaches the critical conditions. Therefore, using the method can determine positions of all weak rods, rod bearing conditions and the degree of each rod approaching to the critical conditions, design direction of local reinforcement of the truss structures is indicated, potential risks are eliminated at the design stage, and market competitiveness of products is improved.

Description

technical field [0001] The invention belongs to the field of hoisting and transporting machinery trusses, and relates to the analysis of truss structures, in particular to a method for determining weak members of the truss structures in hoisting and transporting machines. Background technique [0002] The truss structure has the advantages of light weight and strong bearing capacity, and is widely used in the truss arms of lifting and transportation machinery (such as crawler cranes). Due to the particularity and importance of the hoisting and transporting equipment's operating occasions and hoisting objects, it is required to have a high degree of safety and reliability. The lattice arm is one of the main operating equipment of the hoisting machinery. Its load-carrying capacity is closely related to the lifting performance of the whole machine. The failure of a rod may lead to catastrophic accidents. Therefore, it is particularly important to analyze the weak member of the...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for determining the weak members of the truss structure in the hoisting and transporting machinery, and to judge whether the members have reached a critical state according to the actual stress state of the members, which solves the problem of the prior art. Existing in the problem of only checking the local member and not considering the end bending moment of the compression member

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