Crane Girder Research Articles

Optimal sensor placement for space modal identification of crane structures based on an improved harmony search algorithm

The problem of optimal sensor placement plays a key role in the success of structural health monitoring (SHM) systems. In this study, a new method is presented to investigate the optimization problem of sensor placement on gantry crane structures. The method is a combination of an improved harmony search (HS) algorithm and the modal assurance criterion (MAC). Firstly, we review previous studies on setting reasonable values for HS parameters that have the most impact on the result, and highlight the lack of general rules governing this aspect. Based on more efficient HS algorithms resulting from those studies, we apply our proposed technique to the optimization problem of sensor placement on gantry crane structures. The purpose of the optimization method is to select the optimal sensor locations on gantry crane girders to establish a sensor network for an SHM system. Our results show that the HS algorithm is a powerful search and optimization technique that can lead to a better solution to the problem of engineering optimization. The mode of a crane structure could be identified more easily when different mode shape orientations are considered comprehensively.

Camber deformation estimation of bridge crane and energy-consumption analysis

The crane is a mechanical device used to move materials in modern production. It plays a very important role in the national economy by greatly reducing labor intensity, improving production efficiency, and promoting social development as an indispensable auxiliary tool. The energy consumption of a crane is very large. There are several factors influencing energy loss, especially the camber of the girder, which is thought to compensate for the operation downwarping and, thus, decrease the energy consumption of trolleys with improved operation performance. Thus, analysis and calculation of the camber for crane girder is necessary in order to design a reasonable camber curve for the compensation of girder deformation by self-weight and loading. In this study, the deformation source is analyzed, and an estimation model of camber for the bridge crane is proposed. The camber is theoretically discussed and estimated with respect to self-weight, wheel pressure, and welding. As a result, the optimal corresponding camber curve that could compensate the deformations by self-weight, wheel pressure, and welding were obtained. Calculation of the energy consumption of the trolley is also presented. By using a 50-t, 31.5-m double girder crane as the research object, calculation of its camber and design of the reasonable camber curve for energy-saving were analyzed and demonstrated. These results may provide a design reference for girder camber curve and validation of the effectiveness of crane simulation modeling.

Study on Prediction Deflection of at the Girder Midspan of Large Tonnage Gantry Crane Rigid Legs

It is the most important inspection index of the deflection value for the girder of gantry crane under rated load in the overall test. In the overall test for large tonnage gantry crane which prepared for experimental weight is very difficult at the site, or even impossible perform test. In the text, it is deduced the girder deflection curve equation where considering the effects of the leg bending moment to the girder deflection When the concentrated load is applied to the position of L/2,L/3 and 2L/3 of the girder. The girder deflection value can be obtained under small load at the position of L/2,L/3 and 2L/3 of the girder and the actual moment of inertia of the girder and two side leg can be obtained. In this way, the deflection of the large tonnage gantry crane are predicted through the data of the three-position method in the small load test. Three-position small load test method provides a practical and effective method for the prediction of the girder deflection of large tonnage gantry structure.

An Effective Damage Evaluation Method for Crane Girder Based on SVI and LSSVM

Health assessment of the girder is crucial to an overhead traveling crane. This paper presents an intelligent damage identification method for the girder based on stiffness variation index (SVI) and least squares support vector machine (LSSVM). In the method, the SVI indicators, which have high resolution to environmental noise, serve as the damage feature to detect damage locations. Moreover, the SVI indicators are input to the LSSVM classifier for identifying the actual damage level of the girder. A case study on girder damage identification demonstrates that the method could determine the actual conditions of the girder structure accurately.

The Research of Gantry Crane Girder Damage Problem by Modal Analysis Method

most crane damage identification of the work has focused on the static analysis, that can't explain whether the crane has a damage or not by this way. So the paper explained the modal signal to analysis this problem , Used 300 tons gantry crane’s beam for background and ANSYS software as a tool was used for numerical simulation. The purpose is to find difference between the damage beam of the crane and health one,because if there was a damage on the beam , the formations and frequency will be changed. This theory of analysis is based on the vibration equation. In order to illustrate it better, the wavelet analysis method as a tool has been used ,in this case the signal was filtered, we can judge the damage location from the three dimensional curve. The basic aim of this paper is to arrive at a better way to judge the damage.Through the above analysis, the results proved the author's idea, identify structural’s damage basically, but it still need further research.

Design, Analysis and Optimization of Overhead Crane Girder

Design, Analysis and Optimization of Overhead Crane Girder

Modal Analysis of Crane Girder Based on ANSYS Workbench

Finite element modal analysis of main girder of bridge crane is conducted, the natural frequencies and the vibration-made vectors of the first 6 orders are obtained, and the vibration hazardous areas are found. It provides a theoretical basis for optimal design and dynamics analysis for girder. The natural frequency and mode shape animation of the modal analysis can be used as the optimal design reference of the girder. Rational optimization of girder is able to avoid the resonance frequency region, which will help to improve the reliability and life-span of the girder.

Research on Mechanical Mechanics with the Finite Element Analysis and Structure Optimization of Large Span Gantry Crane Box Beam

Large span gantry crane girder structure has a direct effect on the performance of the whole machine. This paper,by using ANSYS, gets the distribution of the stress and deformation of the box girder under different working conditions, and verifies that the box girder structure can well meet the requirements of the mechanical properties. On this basis, it establishes the objective function and constraint conditions of box girder structure, and gets the best work parameters by using Matlab to optimize the structure. The results of structure optimization can guide well in the designing and manufacturing of similar products.

Periodic Topology Optimization of the Box-type Girder of Bridge Crane

The length of box-type girder of bridge crane is much greater than the height and width. It is difficult to obtain a solution or a clear and periodic topology configuration using conventional algorithm. In order to obtain a periodic structure which is easy to manufacture, periodic topology optimization is applied to the lightweight design of bridge crane's girder. The optimization domain of girder is divided into some sub-domains and the relation between sub-domains and optimization domain is structured. The mathematical model of girder for periodic topology optimization is built, in which mean compliance is taken as objective function under volume constraint condition. Periodic topology optimization of girder is researched under the strength and static rigidity criterion. Results show that periodic holes are appeared in sub-domains during optimization process. Until periodic topology optimization is over, a similar trussed topology configuration is obtained. Even when the number of sub-domains is different,periodic topology configuration which has a good consistency and manufacturability is achieved. A feasible approach is proposed aiming at lightweight design for bridge crane.

Effect of Welding Procedure on Main Girder Fatigue Property

Hoisting machinery is an important part of the equipment manufacturing industry, and the general bridge crane is the most widely used hoisting machinery. The main girder of bridge crane is the main load-bearing structure. Further, fatigue failure of main girder usually occurs not on the material itself but in the welding joint. The article has carried out three groups of experiments, which are experiment on fatigue property under vertical force, experiment on fatigue property under the comprehensive function of vertical force and horizontal force and experiment on failure mode of main girder under the prefabricated crack, to further discuss the effect of welding procedure on main girder fatigue property. Finally the following three conclusions are obtained. Firstly, the crack occurs closely to the middle position of welding place of the lower board and the main web, with the trend of scaling up along the main web perpendicular to the welding place. Secondly, the crack occurs on the main web close to the upper board, with the two-way expansion trend. Thirdly, fatigue failure cracks do not occur in the welding joint except the prefabricated crack position close to the square steel rail after the cyclic loading of two million times on main girder, which indicates that the uniformity of welding quality has an importance influence on the fatigue reliability of the whole main girder.

Application of Derrick Crane Girder Method for Hoisting Precast Box Girders of Bridge

Combined with the engineering project of a bridge in Lanzhou, the derrick crane girder method in the special terrain conditions of the construction technology and process is introduced in detail, also the internal force of steel wire rope is calculated in detail. After applying in practical engineering, it proves that derrick crane lifting method is not only safe and reliable but also economical and feasible.

Strength Analysis and Optimal Design for Main Girder of Double-Trolley Overhead Traveling Crane Using Finite Element Method

As special equipment for material hoisting and carrying, the double-trolley overhead traveling crane develops rapidly in the field of mechanical engineering. In order to improve the safety, reliability, and economy, the lightweight design for the crane is crucial, which mainly contains two important fundamental works: one is the prediction of the limit load-bearing ability and the other one is the optimization. In this paper, a three-dimensional parametric finite element model is established and the limit load-bearing ability of the main girder of a true crane is predicted using the arc-length algorithm and nonlinear stabilization algorithm, respectively. Finite element analysis indicates the existing double-trolley overhead traveling crane shows a large strength allowance. The subsequent optimal design which aims to achieve a perfect match between the mechanical performance and weight is conducted based on the strength analysis. Specially, the software platform of optimal design for double-trolley overhead traveling crane is developed to reach the integrated parametric design interactively. The proposed numerical methods which are highlighted by an optimal design platform implement the lightweight design conception efficiently. By numerical analysis, this research is demonstrated to provide theoretical and technical support for promoting the lightweight design and safety evaluation of cranes.

Calculation of Condition-based Maintenance Inspection Period for the Girder of Crane

Calculation of Condition-based Maintenance Inspection Period for the Girder of Crane

The Dynamic Analysis of Gantry Crane Girder under Lifting Process

In order to get the displacement response curve of the Gantry Crane Girder under three stage of lifting process, the vibration differential equation and displacement response expression were deduced, combining with the actual case, the displacement response expression and displacement response curve were deduced in the load duration time 0.8 s and 0.2 s. The results show that: the lifting process is an important factor affecting the structural vibration; Displacement peak and load duration time are inversely proportional; Increase the load duration time can reduce the vibration of the structure.

The Experimental Study on Steel Crane-Girder before and after Reinforcement

This article focuses on a cracking steel crane girder of one factory, on the basis of extensive investigation and research on the fatigue damage of cracking steel crane girder at home and abroad. Sectional stress is redistribution and the stress concentration phenomenon of the crack tip has been alleviated. After reinforcement, the local stiffness of the upper flange and web greatly increases, The results show that it can extend the fatigue remaining service life of fatigue cracking of the steel crane girder by increasing the effective cross section area and stiffness, and it is a good guide on reinforcement and maintenance of actual industrial plant cracking steel crane girder.

Finite Element Analysis in Dynamic Conditions of Bridge Crane Beam

On the basis of analysis of the existing problems in the bridge crane of today's society, bridge crane girders were modeled and calculated by using three-dimensional design software, then discussed its finite element analysis. It turns out the research and analysis of the main beam in load in static and dynamic conditions. Through a comparative study of displacement diagram and stress-deformation diagram in the case of loading inertia force or no inertia force, it provides important reference for the bridge crane design, optimization, and lightweight optimization.

Fatigue Research on Welding Joint of the Main Girder in Bridge Crane

Fatigue problems about large sized structure components ,such as bridge crane girder , has always been the bottleneck of mechanical products lightweight, reliability, security. In order to study fatigue problem about crane girder in the actual conditions, the dangerous spot of the girder is identified by using the finite element method to analyze structural stress. By simplified model , set up to reflect the main beam welding details of the characteristics of the small size of the process welding fatigue specimen model, and carried out a series of fatigue life test. Specimen fatigue test results quantitative descript the actual fatigue life of the bridge crane girder welded structures. By data fitting, the S-N curve equation of the bridge crane girder include the specific materials, the stress ratio, the welding process and special structure is obtained. It provides a scientific basis and practical methods to solve weld fatigue life design and the remaining life prediction about the crane girder.

The Calculation of Initial Inspection Interval of Condition-Based Maintenance for Special Equipments

Lacking of failure samples, the estimation of MTBF of special equipments is imprecise. Half of the MTBF is regarded as inspection period in classical condition-based maintenance analysis. Because of ignoring reliability life changing of the product, maintenance with fixed period usually leads to more or less of inspection and replacement. According to factory and laboratory failure data, reliability estimation modal of small samples is built for crane based on Bayes theorem, and reliability forecast of the girder of crane is realized. Further more; for special equipments with potential failure mode, first inspection period model of condition-based maintenance analysis based on RCM is set up, on the basis of maintenance cost and availability strategy, the calculation methods of optimal inspection periods are given. This research provides a reference for safety evaluation and inspection strategy establishing for condition-based maintenance of mechanical-electrical special equipments which lack failure data of factory and laboratory.

Lightweight Design and Research of Box Girder for Double Girder Bridge Crane

With a design of the box girder of bridge crane for the rectangular right track girder, rectangular side rail girder and two trapezoidal side rail girder, MATLAB optimization tool is carried out to calculate the discrete variable by homing method one by one. Then the discrete variable which is the thickness of the steel plate used in box girder is used to determine the shape of the cross-section of box girder.

The Application of Roll Forming Technology in the Production of the Crane U Type Main Girder

The traditional LD type electric single-girder crane beam is made from several U type grooves by welding them together. For many years, U type groove is usually made from 5mm or 6mm steel plate which is stamped and formed by rolling machine. Through analysis of the problems and the disadvantages about the traditional producing process of LD type electric single-girder crane girder, put forward the improvement of cold roll forming process. The process has no welding seam, and allows a girder manufacture to achieve higher quality and efficiency, and has low consumption, low pollution.