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Method for determining stability critical force of crane nth-order telescopic boom

A determination method, a technology for telescopic arms, applied in computer-aided design, special data processing applications, instruments, etc., can solve problems such as inability to meet

Active Publication Date: 2018-02-09
TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At this time, the use of codes cannot meet the needs of actual engineering, so a method is urgently needed to solve the critical force of stepped columns of 5th order and above more conveniently and quickly

Method used

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  • Method for determining stability critical force of crane nth-order telescopic boom
  • Method for determining stability critical force of crane nth-order telescopic boom
  • Method for determining stability critical force of crane nth-order telescopic boom

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0106] Embodiment 1: Known as figure 2 The shown second-order stepped column model calculates its critical force, l 1 = 15.5m, l 2 =29.9m, I 1=43.26×10 -3 m 4 , I 2 =26.09×10 -3 m 4

[0107] A method for determining the stability critical force of the n-order telescopic boom of a crane disclosed in this embodiment includes the following steps:

[0108] Step 1: Establish an n-step stepped column model and derive the instability characteristic equation.

[0109] Such as figure 2 As shown, the n-order telescopic arm stepped column model refers to a combination of n equal-section columns, from the fixed and constrained end of the bottom surface to the free end of the top, respectively 1st, 2nd, 3rd, ...... The nth step ladder column; and the cross-sectional area of ​​the column also decreases sequentially. The length from the fixed restraint end of the bottom surface to the top of the first step ladder column is l 1 , the length from the fixed constraint end of the b...

Embodiment 2

[0154] For the second-order stepped column, in order to compare with the length coefficient in the national standard GB3811, use such as Figure 4 The model shown is valid for combinations of jib lengths and sections (α 1 =0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70) (β 2 =1.1, 1.2, 1.3, 1.6, 1.9, 2.2, 2.5) were calculated respectively and compared with the calculation results using ANSYS17.0, the results are as follows Figure 5 Place.

[0155] The length coefficient value μ obtained by the method of this embodiment 2 It is very close to the difference calculated by using ANSYS17.0, and the maximum relative error is 1.7×10 -4 . With the second stepped column (I 2 ) of the moment of inertia increases, the length coefficient μ 2 decreases, that is, the critical force of the stepped column increases gradually; with the second stepped column (I 2 ) relative to the reduction in length, the length coe...

Embodiment 3

[0156] Embodiment 3: compare with national standard GB3811

[0157] Table 3 is a comparison of the length coefficients using the three-step ladder column of the present invention,

[0158] Table 1 Calculation length coefficient μ of the three-step ladder column 2 and compare

[0159]

[0160]

[0161] It can be seen from Table 1 that for the three-step ladder column, its length coefficient value μ 2 It is very close to the difference calculated by using ANSYS17.0, and the maximum relative error is 1.8×10 -5 , and found that the missing μ in GB3811 2 The value is calculated according to the interpolation method, and its value has high linearity in a small range, and the interpolation error is small.

[0162] Table 2 Calculation length coefficient μ of four-step ladder column 2 and compare

[0163]

[0164]

[0165]

[0166]

[0167] Table 2 gives the value of the length coefficient μ of the four-step ladder column 2 , the missing μ in GB3811 2 The valu...

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Abstract

The invention discloses a method for determining stability critical force of a crane nth-order telescopic boom, relates to a recursion formula and a numerical solution of critical force of telescopicengineering crane booms, and belongs to the field of structural design of large-sized mechanical equipment. The method comprises the following steps: 1, establishing an nth-order stepped column model,and concluding an instability character equation; 2, concluding a recursion transcendental equation specific to the instability character equation in the step 1; 3, acquiring a numerical solution forthe transcendental equation in the step 2; 4, solving critical force P according to the numerical solution; and 5, getting a length coefficient [mu]2 of an nth-order stepped column according to the critical force determined in the step 4 in order to solve actual engineering problems. Through adoption of the method for determining the critical force of the nth-order stepped column crane telescopicboom, the maximum lifting weight of a telescopic crane can be determined accurately, and the material use and the dead weight can be reduced, so that a lightweight design of the telescopic boom is realized.

Description

technical field [0001] The invention relates to a recursive formula and a numerical solution for the critical force of a telescopic boom engineering crane boom, in particular to a method for determining the critical force of the n-order telescopic boom stability of a crane, which belongs to the field of structural design of large-scale mechanical equipment. Background technique [0002] In recent years, with the extensive use of high-strength steel and the maturity of automatic single-cylinder latch technology, multi-section box-shaped telescopic booms have been widely used in large-scale construction cranes. As the height of the steel structure increases, the cross-sectional area will inevitably increase accordingly. In order to make reasonable use of materials and reduce weight, the cross-section of beams and columns must change along the axial direction; It is widely used in various mechanical equipment such as engineering cranes and high-altitude rescue vehicles, and its...

Claims

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Application Information

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IPC IPC(8): G06F19/00
CPCG06F2119/06G16Z99/00
Inventor 姚峰林孟文俊赵婕张文军佘占蛟石国善
Owner TAIYUAN UNIVERSITY OF SCIENCE AND TECHNOLOGY
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