Method for adjusting internal force of steel wire rope in large hoisting calculation
By introducing rigid elements of the crane hook and other finite element elements, and adjusting the internal forces of the wire rope, the problem of uneven stress on the wire rope in large-scale hoisting calculations was solved, thus achieving accuracy and safety in hoisting calculations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-04-03
AI Technical Summary
In large-scale hoisting calculations, due to uneven stress caused by errors in wire rope length, existing technologies cannot accurately simulate the internal forces of the wire rope, resulting in distorted hoisting strength calculations and posing safety risks.
Finite element methods, including crane hook rigid unit, crane hook spring unit, wire rope rod unit, shackle rigid unit, and adjustment mass unit, are used to simulate the internal force of the wire rope by adjusting the node position and lever arm length, ensuring the accuracy and safety of the hoisting calculation.
Consistent simulation of internal forces in wire ropes was achieved, ensuring the accuracy and safety of hoisting calculations, reducing structural stress unevenness, and improving hoisting reliability.
Smart Images
Figure CN121786993A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for adjusting the internal force of wire ropes in large-scale hoisting calculations. Background Technology
[0002] In shipbuilding and marine engineering and other large-scale engineering operations, numerous large sections / components require hoisting. These large sections / components are very heavy, and the hoisting design, calculations, construction, and inspection are all carried out at the highest level. The hoisting of large sections / components uses multiple wire ropes to connect the lifting points of the sections to the crane hook. Due to errors in the length of the wire ropes, it cannot be guaranteed that they will bear force completely and simultaneously. A common practice is to fold a single wire rope in half to use as a loop. When the wire rope is under stress, its length can be automatically adjusted to ensure uniform force distribution. The hoisting strength calculation typically uses the finite element method. The conventional approach is to use rod elements in finite element software to simulate the connection between the lifting points and the hook. However, this method can lead to inconsistent internal forces on both sides of the wire rope. This is because the loop is not simulated, resulting in uneven force distribution, distortion, and potential risks. Summary of the Invention
[0003] The purpose of this invention is to provide a method for adjusting the internal force of wire ropes in large-scale hoisting calculations that can accurately simulate actual conditions, is simple and reasonable, is easy to adjust, and ensures the accuracy and safety of large-scale hoisting calculations.
[0004] The technical solution adopted by this invention to achieve the above objectives is: a method for adjusting the internal force of wire rope in large-scale hoisting calculations, comprising the following steps: a. A rigid unit (2) for the crane hook head is adopted. The rigid unit (2) for the crane hook head consists of a main node and a slave node. The main node is connected to the boundary constraint (1) of the crane hook head, and the slave node is connected to the wire rope rod unit (4). By adjusting the position of the slave node, the lever arm length is adjusted to realize the distribution and adjustment of the internal force of the wire rope. b. Connect the crane hook spring unit (3) to the crane hook rigid unit (2), apply constraints to the ends to constrain the horizontal displacement, realize the supplementary constraint effect, and ensure the degree of freedom requirements of finite element calculation; c. Use a wire rope rod unit (4) to connect the crane hook rigid unit (2) and the lifting eye plate (5) on the large segment / component (8) to simulate the tension of the wire rope; d. A shackle rigid unit (6) is set on the large segment / component (8), and the wire rope rod unit (4) is connected to the shackle rigid unit (6) to realize the transmission of force; e. The lifting eye plate (5) and the large segment / component (8) are an integral structure to ensure the lifting strength. The large segment / component lifting reinforcement (9) is set at the lifting eye plate (5) to reduce the stress level during lifting. f. Use the adjustment mass unit (7) to adjust the center of gravity of the large segment / component (8) to be consistent with the weight control report; g. Adjust the position of the crane hook boundary constraint (1), monitor the internal force of the lower spring unit (10), minimize the internal force of the lower spring unit (10), and thus ensure the balance of the large segment / component (8) and the calculation results. h. The above steps are an iterative process. Through repeated adjustments, the actual internal force load of the wire rope rod unit (4) is obtained, the internal force of the lower spring unit (10) is minimized, and the lifting strength analysis is completed until it meets the actual situation.
[0005] In step c, the lifting eye plate (5) and the wire rope rod unit (4) are connected by a shackle pin to simulate the rotation of the pin.
[0006] This invention provides a method for adjusting the internal force of wire ropes in large-scale hoisting calculations. By introducing a rigid hook unit to connect the hook constraint point with the wire rope rod unit, the internal force of the wire rope is adjusted. The result is consistent with the actual situation, making the hoisting calculation more accurate and effectively ensuring the safety of the hoisting. Attached Figure Description
[0007] Figure 1 This is an overall layout diagram of a method for adjusting the internal force of wire ropes in large-scale hoisting calculations according to the present invention.
[0008] Figure 2 This is a schematic diagram of the rigid unit of the crane hook in a method for adjusting the internal force of the wire rope in a large-scale hoisting calculation according to the present invention.
[0009] Figure 3 This is a schematic diagram of the crane hook spring unit in a method for adjusting the internal force of a wire rope in a large-scale hoisting calculation according to the present invention.
[0010] Figure 4 This is a schematic diagram of the adjustment mass unit in a method for adjusting the internal force of a wire rope in a large-scale hoisting calculation according to the present invention.
[0011] Figure 5 This is a schematic diagram of the wire rope internal force results in the method for adjusting the internal force of wire rope in large-scale hoisting calculations according to the present invention.
[0012] Figure 6 This is a schematic diagram of the spring reaction force of a wire rope in a method for adjusting the internal force of a wire rope in a large-scale hoisting calculation according to the present invention.
[0013] Figure 7 This invention relates to a method for adjusting the internal force of a wire rope in large-scale hoisting calculations, and presents a wire rope stress cloud diagram. Detailed Implementation
[0014] like Figures 1 to 7 As shown, the method for adjusting the internal force of the wire rope in large-scale hoisting calculations includes the following steps: a) Using a rigid element 2 for the crane hook head, which consists of a master node and slave nodes, the master node connects to the crane hook head boundary constraint 1, and the slave node connects to the wire rope rod element 4. By adjusting the position of the slave node, the lever arm length is adjusted to achieve the distribution and adjustment of the internal force of the wire rope. The introduction of the rigid element 2 for the crane hook head increases the freedom of the entire lifting system, leading to insufficient constraints. b) Connecting the crane hook head spring element 3 to the rigid element 2 for the crane hook head, and applying constraints at the ends to constrain horizontal displacement, achieves supplementary constraints and ensures the degree of freedom required for finite element calculation. The crane hook head spring element 3 only constrains horizontal displacement and has extremely low stiffness, so it has no impact on the results of the entire lifting system. c) Using The wire rope rod unit 4 connects the crane hook rigid unit 2 and the lifting eye plate 5 on the large segment / component 8 to simulate the tension of the wire rope. The lifting eye plate 5 and the wire rope rod unit 4 are actually connected by a shackle pin to simulate the rotation of this pin. d. A shackle rigid unit 6 is set on the large segment / component 8, and the wire rope rod unit 4 is connected to the shackle rigid unit 6 to achieve force transmission. e. The lifting eye plate 5 and the large segment / component 8 are an integral structure to ensure lifting strength. A large segment / component lifting reinforcement 9 is set at the lifting eye plate 5 to reduce the stress level during lifting. f. Multiple adjusting mass units 7 distributed inside the large segment / component 8 are used to adjust the center of gravity and weight control of the large segment / component 8. Consistent, the weight control report is compiled and calculated by various professional engineers to determine the center of gravity of the large segment / component 8. It is highly accurate and can be used as the basis for weight adjustment during hoisting calculation; g. Adjust the position of the crane hook boundary constraint 1, monitor the internal force of the lower spring unit 10 at both ends of the large segment / component 8, minimize the internal force of the lower spring unit 10, and thus ensure the balance of the large segment / component (8), and ensure the accuracy of the hoisting calculation results. The calculation results include the structural stress, the internal force of each wire rope, and the displacement of each segment; h. The above steps are an iterative process. Through repeated adjustments, the actual internal force load of the wire rope rod unit 4 is obtained, and the internal force of the lower spring unit 10 is minimized within the allowable requirements. Within the specified range, the internal force of the spring unit generally needs to be less than one-thousandth or five tons of the total segment weight to reduce the impact of the spring on the local stress of the structure. The lifting strength analysis conforms to the actual situation, that is, the internal forces of the wire rope loops in the model are equal or close, which is consistent with the actual use of wire ropes with folds. The structural stress distribution is uniform, safe and reliable. The method for adjusting the internal force of the wire rope in the large-scale lifting calculation of this invention introduces the main node of the crane hook rigid unit to connect the lifting point, and the secondary node to connect two wire rope rod units. By appropriately adjusting the coordinate position of the secondary node, the internal force of the wire rope is adjusted, so that the internal force of the wire rope loops is consistent. It can accurately simulate the actual situation, is simple and reasonable, and is easy to adjust, ensuring the accuracy and safety of large-scale lifting calculation.
Claims
1. A method for adjusting the internal force of a wire rope in large-scale hoisting calculations, characterized in that, Includes the following steps: a. A rigid unit (2) for the crane hook head is adopted. The rigid unit (2) for the crane hook head consists of a main node and a slave node. The main node is connected to the boundary constraint (1) of the crane hook head, and the slave node is connected to the wire rope rod unit (4). By adjusting the position of the slave node, the lever arm length is adjusted to realize the distribution and adjustment of the internal force of the wire rope. b. Connect the crane hook spring unit (3) to the crane hook rigid unit (2), apply constraints to the ends to constrain the horizontal displacement, realize the supplementary constraint effect, and ensure the degree of freedom requirements of finite element calculation; c. Use a wire rope rod unit (4) to connect the crane hook rigid unit (2) and the lifting eye plate (5) on the large segment / component (8) to simulate the tension of the wire rope; d. A shackle rigid unit (6) is set on the large segment / component (8), and the wire rope rod unit (4) is connected to the shackle rigid unit (6) to realize the transmission of force; e. The lifting eye plate (5) and the large segment / component (8) are an integral structure to ensure the lifting strength. The large segment / component lifting reinforcement (9) is set at the lifting eye plate (5) to reduce the stress level during lifting. f. Use the adjustment mass unit (7) to adjust the center of gravity of the large segment / component (8) to be consistent with the weight control report; g. Adjust the position of the crane hook boundary constraint (1), monitor the internal force of the lower spring unit (10), minimize the internal force of the lower spring unit (10), and thus ensure the balance of the large segment / component (8) and the calculation results. h. The above steps are an iterative process. Through repeated adjustments, the actual internal force load of the wire rope rod unit (4) is obtained, the internal force of the lower spring unit (10) is minimized, and the lifting strength analysis is completed until it meets the actual situation.
2. The method for adjusting the internal force of wire rope in large-scale hoisting calculations according to claim 1, characterized in that: In step c, the lifting eye plate (5) and the wire rope rod unit (4) are connected by a shackle pin to simulate the rotation of the pin.