Finite Element Model Establishment and Strength Analysis of Crane

Boom

Linyan Zhang

, Hongliang Zhang

1, a, *

,Changguo Lu

Department of Computing,Yingkou Institute of Technology, Yingkou,China

Keywords: Crane Boom, Finite element analysis, Strength Analysis.

Abstract: This paper is devoted to the strength analysis of crane boom with Ansys software. The results of strength

analysis and theoretical calculation are compared and analyzed, and a method of using software to analyze

the strength of crane boom is discussed. Firstly, using SolidWorks software, the three-dimensional model of

each jib of the main arm of heavy crane is established by means of shell pulling, which is saved in x-t

format. Secondly, the three-dimensional model is imported into Ansys software, and the finite element

model of heavy crane boom is established by assigning attributes and meshing. Thirdly, the crane boom

priority model is constrained and loaded, and the static simulation is carried out. Finally, the simulation

results and theoretical results are compared and analyzed to verify the accuracy of the model (SINGH B,

et.al, 2011; TOMASZ G, et.al, 2011).

1 ESTABLISHMENT OF FINITE

ELEMENT MODEL OF CRANE

BOOM

1.1 Applying SolidWorks Software to

Build Three-Dimensional Model

Firstly, the three-dimensional model of crane boom

is established by using SolidWorks software. In

SolidWorks, all boards extract the middle surface,

and all tubes extract the axis to build a three-

dimensional model. The model of the crane boom

needs to be established, including the boom root, the

boom head, the completed 3m, 6m, 12m middle

boom. According to the requirement of the subject,

the structure size of the arm frame of the main arm is

determined. According to the size requirement, the

arm head and the arm root of the main arm are

drawn. The model is shown in Figures 1 and 2.

Fig 1. Arm Root.

Fig 2. Arm Head.

1.2 Introduction to Ansys Software

Ansys software is developed by American Ansys

Company. It is a finite element analysis software

which integrates structure, fluid, electric field,

magnetic field, sound field and thermal analysis. It

has corresponding interfaces with most software

(such as Pro/Engineer, Hypermesh, Adams, Nastran,

Ideas, etc.), and can realize data sharing and

exchange between them. The cell types used in this

paper are shell 63 unit, beam 188 unit, link 180 unit

and mass 21 unit.

1.3 A Simplified Scheme for Modeling

Process Using Ansys Software

Beam 188 beam element is commonly used in Ansys

to simulate the main chord and web members. This

element can define the cross-section shape and also

simulate the mechanics of the main chord and web

192

Zhang, L., Zhang, H. and Lu, C.

Finite Element Model Establishment and Strength Analysis of Crane Boom.

DOI: 10.5220/0008850001920196

In Proceedings of 5th International Conference on Vehicle, Mechanical and Electrical Engineering (ICVMEE 2019), pages 192-196

ISBN: 978-989-758-412-1

members. The shell 63 element is used to simulate

the plate of the arm head in the boom. The shell 63

element is commonly used in Ansys software. It is

convenient to use. For other pull plates, it is

simulated by link8 element, which is a three-

dimensional bar element and is a tension and

compression element in the direction of bar axis.

Beam 188 beam element model is used to analyze

the chord and web members.

1.4 The Finite Element Model of Heavy

Crane Boom Is Established By

Using Ansys Software

In SolidWorks, all the boards are extracted from the

middle surface, and all the tube axes are extracted to

build a three-dimensional model, which is saved in

x-t format and imported into Ansys for modeling. In

Ansys, shell 63 unit is used for board, beam 188 unit

is used for tube, mass21 unit is used for key point

and link 180 unit is used for pulling board.

In Ansysysy, the solid models established from

Solidworks are imported to define their material

properties, the real constants are given to the plates

according to the thickness of the plates, and the

cross-section properties of the tubes are defined

according to the diameter and thickness of the tubes.

Finite element mesh analysis is carried out on them,

and mesh errors are checked and modified, and finite

element models are established. Fig. 3 is the arm

root finite element model, and Fig. 4 is the arm head

finite element model.

Fig 3. Arm Root Finite Element Model.

Fig 4. Finite Element Model of Arm Head.

The arm is connected with the arm root by

moving, writing out and reading operation. The

finite element model of the 13m basic main arm is

established, as shown in Fig. 5.

Fig 5. Finite element model of 13m main arm.

2 STRENGTH ANALYSIS OF

CRANE BOOM

As shown in Figure 6, the basic main arm of 13m is

adjusted to the working state of minimum radius and

maximum hoisting by moving and rotating.

According to the position of the lower hinge point of

the pulling plate in the working condition, the key

points are established and the connecting arms are

separately. For the two pulling plates, the link188

element can only be divided into one cell. The upper

end of the drawing plate and the hole are connected

by rigid area.

Finite Element Model Establishment and Strength Analysis of Crane Boom

193

Fig 6. Force model of 13m main arm.

In the articulated position of the lower arm root

and the articulated position of the upper arm head,

the rigid region is established by mass21, and the

rigid region is also established in the contact

position of the tube and the plate. In the articulated

position of the lower end of the arm root, the

constraints of ux, uy and UZ displacement directions

are added, and the lower end of the pull plate is fully

constrained. Add 539 KN downward force to the

arm lifting position, and add to the whole system.

Fig 7. Total stress nephogram of 13m main arm.

From the total stress nephogram of the main arm,

it can be seen that the maximum displacement of the

main arm is 28.314 mm, the maximum stress is 252

MPa, and the position of the main arm appears in the

arm head. See Fig. 7 for details.

Fig 8. Maximum stress nephogram of Figure 8.

From Figure 8, it can be seen that the maximum

stress position of the slab is in contact with the

lifting load, and the stress near the slab is relatively

large, averaging about 135 MPa. Q235 is adopted in

this design, and its allowable stress is 213MPa,

which is larger than the result of finite element

calculation and meets the strength requirement. For

the position where the maximum stress occurs due to

the smaller chamfer, there is the possibility of stress

concentration, so we can try to improve the design.

Fig 9. Maximum stress nephogram of Q345 main chord.

From the stress nephogram of the main chord, it

can be seen that the maximum position of the actual

stress appears on the lower main chord with the

upper arm, and its maximum stress value is 281 MPa.

The stress of the lower main chord is larger than that

of the upper one, which accords with the fact that the

upper main chord is under tension and the lower

main chord is under compression. The maximum

stress distribution of the lower main chord is about

220 MPa on average. The allowable stress of Q345

is 313 MPa, which is larger than the result of finite

element calculation and meets the strength

requirement.

Fig 10. Stress nephogram of pipe.

Fig. 10 is the stress nephogram of the pipe. The

maximum stress appears at the end of the arm. The

material chosen is Q345. The maximum stress value

is 281 MPa, which is greater than 213 MPa. Its

strength meets the requirements.

ICVMEE 2019 - 5th International Conference on Vehicle, Mechanical and Electrical Engineering

194

Fig 11. Nephogram of Abdominal Canal Force.

Figure 11 shows that the maximum stress of the

abdominal canal occurs at the upper arm, followed

by the root of the arm. The material used is Q235

and its allowable stress value is 109 MPa, which is

larger than the result of finite element calculation

and meets the strength requirement.

3 COMPARISON OF

THEORETICAL

CALCULATION AND

SOFTWARE ANALYSIS

RESULTS OF BOOM

STRUCTURE STRENGTH

According to the theoretical calculation of plate

strength and the strength analysis by ANSYS

software, the results are compared. In the analysis

results of Ansys software, the blue part accounts for

most of the area, and the red part is the largest part

of the plate. As shown in Fig. 12, when the

dangerous section is 10 m away from the root of the

boom:

Figure 12. Hazardous Section Analysis C.









=839.4/4×2093=100.26MPa (1)









 



    

－



  



=490×1.1×

 

－

218.21×3×

 



280.8

－

225.8=55KN.m (2)





（）



=55×





/3.67×





=150MPa (3)

Therefore, the stress of the upper and lower main

chord is zero:









－



=150 MPa

－

100.26MPa=49.74MPa (4)













=150 MPa+100.26MPa=250.26MPa(5)

The stress of the main chord is 49.74 MPa on the

dangerous section, which is 10 m away from the arm

root of the boom. The stress of the lower main chord

is 250.26 MPa. The result of Ansys software

analysis is 242 MPa. The error is about 3.30%.

The theoretical calculation value regards the

whole boom as a homogeneous rigid body, and

simplifies the position of the pulling plate and the

lifting load to the same point, which is different

from the actual value and is not particularly accurate.

Therefore, the theoretical calculation value and the

results of finite element analysis have errors, but the

error is within 5%. The finite element model and the

calculation results can be basically considered.

Correct.

4 CONCLUSION

In this paper, the three-dimensional model of crane

boom is established by Solidworks software, and the

finite element model of crane boom is established by

introducing Ansys software. The strength analysis of

crane boom is carried out by using finite element

model. Finally, the strength analysis results of

application software and theoretical calculation are

compared. The accuracy of strength analysis results

is verified. The research results of this paper have

strong practical and theoretical significance for the

application of crane boom strength analysis in

engineering.

Finite Element Model Establishment and Strength Analysis of Crane Boom

195

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SINGH B, NAGAR B, KADAM B S, et al. Modeling and

finite element analysis of crane boom [J]. International

Journal ofAdvanced Engineering Research and Studies,

2011, 1(1): 51-55.

TOMASZ G, WOJCIECH S. Modeling and research into

the vibrations of truck crane [J]. Scientific Research of

the Institute of Mathematics and Computer Science,

2011, 1(10): 49-60.

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196