Kot Engenharia

Structural analysis of a crane shed extension: Succes story

Structural_analysis_KOT

Introduction

Currently, the handling and transport of large loads is one of the critical issues facing various sectors of industry. One of the pieces of equipment used to move large and/or heavy products is the overhead crane. In addition, this equipment is easy to use, ensures the safety of the workers involved, and saves a considerable amount of time during handling operations. In this regard, it can be concluded that these machines are indispensable in industrial settings. [1]

Cranes can often be seen installed on the roofs of industrial warehouses. The main components of this equipment are the girders, the trolley and the hoist or winch and their functions are described below.

    • Beams: structure through which the car will move;

    • Trolley: mobile equipment responsible for the transverse movement of the load;

    • Hoist or winch: equipment responsible for lifting and lowering the load.

Check out this article on the work carried out by the Kot team on the structural analysis of a shed extension, with the aim of extending the runway of an overhead crane!

Structural analysis

First, a mining company wanted to extend the travel path of one of its overhead cranes from axis 8 to axis 11 (Figure 1). To that end, it asked Kot to conduct a structural assessment of the warehouse where the crane was installed, in order to ensure that the structure could withstand the modification. 

First of all, to provide some context, here are a few definitions used in this analysis.

    • Utilization index (UI): Evaluates the degree of stress to which a structural element is being subjected;

    • Permissible utilization index: Value defined in the standard for approving or disapproving the UI found.

The project began with the modeling of the metal structure using finite elements using PROCAL , software developed by Kot. In addition, the materials used to construct the structure were taken into account during the modeling process. Figure 1 shows the finite elements of the warehouse where the overhead crane is installed.

Kot_Model-in-finite-elements-of-the-hall

Figure 1: Finite element model of the shed - Axes. [2]

Next, after performing a finite element analysis of the structure in question, the applied loads were analyzed and applied to the model. For example, some of the loads considered are listed below.

    • Self-weight: These correspond to the forces due to the mass of all the fixed or mobile components of the shed, as well as mechanical and electrical components and support structures;

    • Wind load: This load case deals with the wind load that the structure is subjected to. The forces are calculated based on the characteristics presented in the standard;

    • Crane load: Corresponds to the load to which the structure is subjected as a result of the presence of cranes.

Subsequently, after the loads were defined and applied, the structural simulation was performed, and the results are shown in Figure 2.

Kot_Simulation of shed structure

Figure 2: Structural simulation of the shed [2].

Graph 1 shows in detail the utilization rates found compared to the permissible utilization rate.

Kot_Structure utilization rates

Graph 1: Structure utilization rates. [2]

In addition, connection elements can be defined as those responsible for joining parts of the structure to one another or connecting the structure to external elements. The primary connection methods used are welds, screws, threaded rods, and pins. In summary, we can classify these elements into two groups:

    • Flexible connection: No resistance to bending moments;

    • Rigid connection: It presents total restriction to bending moments.

Consequently, the next step in the study was to analyze the connecting elements in the structure, and the results can be seen in Figure 2.

Kot_Link utilization rates

Graph 2: Link utilization rates. [2]

Conclusion

Finally, during the evaluation of the results obtained from the structural and connection analyses, no nonconformities were found; therefore, the length of the overhead crane runway was approved, and the mining company was able to proceed with its warehouse expansion project.

In general, structural analyses are relevant to various areas of industry. This makes it possible to accurately identify the loads and stresses acting on industrial assets and to evaluate the structural behavior of the equipment under these stresses. Consequently, it is possible to identify areas where reinforcements may be necessary. In addition, the Finite Element Method is highly applicable, as it allows for the analysis of complex structures with greater intuitiveness and ease compared to Numerical Methods.

One of Kot’s areas of expertise is structural simulations. The company is capable of operating in a variety of industrial contexts and has in-depth knowledge of the assets found in companies. Contact our team for more information and quotes!

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References:

[1] What an overhead crane is and how it works. Kistler Morse, May 15, 2020. Available at: https://www.kistlermorse.com.br/post/o-que-%C3%A9-uma-ponte-rolante-e-como-funciona

[2] Kot Engenharia Collection.

Kot Engenharia Team

With more than 30 years of history and many services provided with excellence in the national and international market, the company promotes the integrity of its clients' assets and collaborates in solving engineering challenges. To achieve this, it uses tools for the calculation, inspection, instrumentation and monitoring of structures and equipment.