Papers by Author: Bin Li

Abstract: Inner climbing tower crane supporting system itself is statically indeterminate structure. This paper would use the force method of structural mechanics to solve this kind of statically indeterminate problem. Through the MATLAB software, it can get the horizontal counterforce of the inner climbing tower crane supporting system diagram which about the cross sectional area of strut and moment of inertia of beam.

Abstract: Basing on the ANSYS finite element analysis, the research takes a flat type tower crane boom on the ear plate and upper chord (round steel) of the connection as example. On the shape of the ear plate, welding form, round steel insert depth and the thickness of the ear plate concrete structure and parameter design are analyzed. Comparing the mechanical properties of bearing model, and then to discuss the ear plate and round steel joint stress concentration problem.

Abstract: Supporting system of external suspension tower crane is the key factor which impairs the safety of the tower cranes. In this article, the problem is studied about the influence of different supporting point stiffness on the force of the tower crane external suspension. Based on the structural mechanics theory, the displacement of the lower statically indeterminate beam and the horizontal displacement of the upper statically indeterminate truss are solved firstly, then the stiffness of the supporting point on the lower beam and the entirety stiffness of the upper horizontal combination struts can be obtained. We can get the optimal supporting structure by drawing the relationship of stiffness1-stiffness2-force which is of significant to the external suspension’s design and installation in Matlab software.

Abstract: The attachment frame forms of the attachment frame were diversified. Different forms had their own characteristics. The models of attachment frame model were set up by using finite element analysis software ANSYS which could create the model to analyze the supporting structure. The article applied load on the attachment frame and calculate the internal force of the pole and the normal force of the wall in four working conditions. The final results were displayed in graphics and list form. Finally, according to the graph and data, the article compared various attachment frame forms and presented a rational analysis.

Abstract: The concept of equivalent stiffness and equivalent negative stiffness is introduced in this paper, established the equivalent relationship between the force acting on the middle of variable cross-section column and the force acting on the top of constant cross-section column on boom tower crane lifting plane and slewing plane by the equivalent stiffness law and the equivalent negative stiffness method, The force on the middle of column is converted into the force on the top of column by the equivalent relationship.

Abstract: This article mainly aims at analysis of local stress of lower chord of inverted triangle cargo boom of tower crane under the wheel pressure, taking the inverted triangle cargo boom of 70300 tower crane as the research object. Separately analyze the effects on the strength of the lower chord which is produced by the down flange, webs and changes of the car action point. Result from the analysis: When the distance between the two webs is too far and the car action points are closer to the webs, the force of lower chord is relatively good. Thickness of the down flange has bigger influence on the lower chord than the webs.

Abstract: In order to improve the interchangeability of a standard section and determine the tower body of the optimal combination-matching, taking 45 combination schemes of three models of tower cranes for example, the ANSYS for hoist boom at working state of the diagonal of tower body have been used to make the calculation and analysis, the distribution map of the total displacement and the axial force at this condition have been obtained. According to the results, the stiffness, strength and stability of tower body have been analyzed. The tower body of the optimal combination-matching is chosen by the fuzzy evaluation method. It is proved that the optimal combination-matching through the fuzzy evaluation method is accord with production requirement.

Abstract: Based on the inverted triangle cargo boom of ST80238 tower crane as the research object, the author took its local down chord as calculation model. ANSYS software is applied to impose the constraints and loads on the model, and the stress and deflection are analyzed. The results show that the top flange of the down chord and the web will be influenced by the axial force of the oblique truss, and larger local stress in the joint position and the surrounding of the oblique truss and the down chord are produced, as well as the largest local stress will be produced in the centre of the connective position, and reducing gradually to the surrounding. In the condition of the box section center line of the down chord is constant, moreover the size of the down flange and the web is increased, and the local stress and vertical deflection nearby the joint of the oblique truss and the down chord will be reduced. Though the research, the local instability of down chord of ST80238 tower crane can be prevented,and a direct reference and basis for box beam of down chord can be provided.

Abstract: This paper is carried out the analysis on structure stress characteristics of the top and low slewing frame of ST6020 tower crane, and gets the stress contours under different working conditions. According to the stress state of the structure and the adjustments of the structure scheme, rational structure of the top and low slewing frame is obtained.

Abstract: When the crane jib is in the maximum elevation angle，luffing jib tower cranes can happen to produce accidents of crane jib backward- tipping. The anti-backward-tipping device is the necessary safety device luffing jib tower crane. Based on the study of several anti-backward-tipping devices, this paper analyzes the causes and forced state of crane jib backward- tipping and proposes several factors to be put into consideration in designing anti-backward-tipping device. It proposes a design method and calculation method of dual-spring anti-backward-tipping device, which has been applied and verified in product design.