Method for determining buckling load-end shrinkage curves of deck longitudinal beam columns supported by cantilever crossbeams

Abstract

The invention provides a method for determining buckling load-end shrinkage curves of deck longitudinal beam columns supported by cantilever crossbeams, and belongs to the technical field of ship structural engineering. The method for determining buckling load-end shrinkage curves of deck longitudinal beam columns supported by cantilever crossbeams comprises the following steps of: 1, establishing a deck longitudinal beam column instability mechanical model after large-scale impact; 2, establishing a cantilever crossbeam mechanical equation and obtaining a lowest-order frequency formula; 3, establishing a cantilever crossbeam torsional rigidity calculation model and determining a torsional rigidity; 4, determining a support rigidity, for a deck longitudinal beam, of a crossbeam; 5, determining a longitudinal beam column buckling curve and a buckling critical load; and 6, determining a critical load-end shrinkage curve of the longitudinal beam column. The method provided by the invention is a theoretical method for rapidly obtaining the buckling load-end shrinkage curves of longitudinal beam columns supported by cantilever crossbeams after large-scale impact damage, so that the calculation is improved; and compared with a nonlinear finite element method, the method has the advantages of shortening the calculation time and improving the efficiency.

Description

technical field [0001] The invention relates to the technical field of ship structural engineering, in particular to a method for determining the load-end shrinkage curve of deck longitudinal beam column buckling supported by cantilever beams. Background technique [0002] Accurate calculation and reasonable evaluation of the remaining strength of the hull can effectively ensure the rationality and safety of the ship structure design. Determining the load-shrinkage curve of the buckling of deck longitudinal beams supported by cantilever beams is the key to determining the remaining ultimate strength of hull girders. [0003] The International Association of Classification Societies (IACS) added the content of residual strength check after hull girder damage to the HCSR code implemented in 2016. HCSR stipulates the depth and height of the damage extent of the collision for the calculation of the surviving ultimate strength of bulk carriers and oil tankers. However, the lengt...

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Problems solved by technology

[0005] Aiming at the above-mentioned problems existing in the prior art, the aim is to provide a load-end shrinkage curve determination method for the buckling of deck longitudinal beams and columns supported by cantilever beams, which simplifies the deck beams within the damage range to one end elastically fixed and one end free. The cantilever beam is used to establish a mechanical model for calculating the instability of deck longitudinal beams and columns after a large-scale collision of the hull; the lowest order frequency is obtained by solving the dynamic equation of the elastically fixed cantilever beam, and then the lowest order frequency is obtained by series expansion and simplification The calculation formula of the fixed end of the beam; by simplifying the structure of the fixed end of the beam to an equivalent thin-walled beam fixed at both ends, the calculation model of the torsional stiffness of the elastic fixed end of the cantilever beam is established, and according to the torsion angle and complex bending deflection of the thin-walled member torsion constraint problem Corresponding relationship, determine the torsional stiffness of the elastic fixed end of the cantilever beam; use the similarity between the stability problem and the free vibration equation of the beam to determine the support stiffness of the elastically fixed cantilever beam to the deck longitudinal; according to the stability theory of the bar system, obtain the elastic support Rigidity coefficient: According to structural mechanics, the ratio of the Euler stress of the multi-span plate frame longitudinal to the Euler stress of the longitudinal as a single-span bar is obtained, so as to determine the buckling load of the longitudinal beam-column supported by the cantilever beam after a large-scale collision damage; Through plasticity correction, determine the critical load of buckling of longitudinal beams and columns supported by cantilever beams after large-scale collision damage; finally, the end contraction curve of critical load of longitudinal beams and columns supported by cantilever beams after large-scale collision damage is obtained by edge function

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