Method for determining critical load of n-order telescopic boom of crane

A telescopic jib and critical load technology, applied in cranes, special data processing applications, complex mathematical operations, etc., can solve problems such as discontinuous derivatives and poor convergence

Active Publication Date: 2021-06-08
SUZHOU UNIV OF SCI & TECH
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a method for determining the critical load of the n-order telescopic jib of a crane in view of the de...

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  • Method for determining critical load of n-order telescopic boom of crane
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  • Method for determining critical load of n-order telescopic boom of crane

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Embodiment Construction

[0065] The present invention comprises the following steps:

[0066] S1. Establish the buckling force model of the stepped column:

[0067] Simplify the telescopic jib to an n-step cantilever column, and draw the buckling model diagram and deformation diagram of the n-step cantilever column as figure 1 As shown, let the total length of the telescopic arm L=l n , the lengths of cantilever columns of each order are l 1 , l 2 -l 1 ,...l n-1 -l n-2 , l n -l n-1 ;

[0068] S2. Suppose the displacement function:

[0069] The coordinate axis is taken with the fixed end at the bottom of the buckling model diagram as the origin, and the displacement function of the stepped cantilever column is assumed to be

[0070]

[0071] Among them, A m and B m is the undetermined expansion coefficient, H 1 =-x 2 / L+x 3 / L 2 , H 2 =3x 2 / L 2 -2x 3 / L 3 ,λ m =mπ / L, for the above expression, it is easy to verify that w(0)=0, w'(0)=0, that is, formula (1) satisfies t...

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Abstract

The invention provides a method for determining a critical load of an n-order telescopic boom of a crane. The method comprises the following steps: S1, establishing a buckling stress model of a stepped column; s2, establishing a displacement function; s3, solving a buckling stress model; s4, verifying the accuracy; and S5, carrying out applicability verification. Aiming at the critical load problem of the telescopic boom of the crane, the buckling load of the telescopic boom is researched by adopting a stepped column model. The invention comprises the following steps: firstly, establishing a displacement function expression of an n-order stepped column based on an improved Fourier series method, then solving by using a Rayleigh-Ritz method in combination with a minimum potential energy principle to obtain an expression of a buckling load, finally solving a plurality of numerical examples, and comparing the obtained result with the result of the existing literature. On the basis, the calculation length coefficient of the stepped column is compared with the length coefficient in the literature, and the accuracy of the method is verified. The invention provides a simpler, quicker and more accurate buckling load determination method for the engineering design of the stepped column.

Description

technical field [0001] The invention relates to the technical field of mechanical structure design, in particular to a method for determining the critical load of an n-order telescopic jib of a crane. Background technique [0002] With the development of modern science and technology, the engineering structure system tends to be large, towering and soft. The stepped column is widely used in the concrete pump truck boom system, crane boom structure, large drill pipe and other structural systems. In the large-scale lifting structure system, the number of stepped booms required is getting larger and larger. Due to the use of high-strength steel, the strength and stiffness of the components have been improved, making the lifting height and lifting capacity larger, and the stability problem has become more and more prominent. The calculation and solution of the instability load has become an important problem. [0003] The buckling research of stepped columns is a hot topic of ...

Claims

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Application Information

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IPC IPC(8): G06F30/20B66C23/687G06F17/12G06F17/15G06F17/16
CPCG06F30/20B66C23/701G06F17/12G06F17/15G06F17/16
Inventor 鲍四元陆健炜
Owner SUZHOU UNIV OF SCI & TECH
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