• JOURNAL OF AGRICULTURE & SOCIAL SCIENCES


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    • Abstract: JOURNAL OF AGRICULTURE & SOCIAL SCIENCES1813–2235/2006/02–3–133–135http://www. fspublishers.orgStress Analysis of Front Axle of JD 955 Combine HarvesterUnder Static LoadingALI JAFARI1, MAJID KHANALI, HOSSEIN MOBLI AND ALI RAJABIPOUR

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JOURNAL OF AGRICULTURE & SOCIAL SCIENCES
1813–2235/2006/02–3–133–135
http://www. fspublishers.org
Stress Analysis of Front Axle of JD 955 Combine Harvester
Under Static Loading
ALI JAFARI1, MAJID KHANALI, HOSSEIN MOBLI AND ALI RAJABIPOUR
Department of Agricultural Machinery, Faculty of Bio-System Engineering, University College of Agriculture and Natural
Resources, University of Tehran, Karaj, Iran
1
Corresponding author’s e-mail: [email protected]
ABSTRACT
JD 955 combines manufactured by Iran Combine Manufacturing Company was modified. Resulting from the applied
modifications, total weight and the loads applied on front axle of modified combine were increased. Stress analysis of front
axle of JD 955 combine under static loading conditions resulted from the applied modifications was performed by using finite
element method. The commercial finite element package ANSYS version 9.0 was used for the solution of the problem.
Numerical results showed that the calculated value of factor of safety is very low and the front axle of JD 955 combine isn’t
strong enough to be installed on the modified combine.
Key Words: Axle; Stress analysis; Combine; Finite element method
INTRODUCTION very good design as this part experiences the worst load
condition of the whole combine. Front axle of JD 955
Iran Combine Manufacturing Company (ICMCO) is combines has no field failure reports.
the greatest Iranian company that produces combines and The main objective in this research was to analyze the
that is committed to excellence and competitiveness in the front axle of JD 955 combine under static loading
national market. The following objectives are pursued in conditions resulted from the applied modifications and
ICMCO’s product development process: investigate the mechanical strength of front axle of combine
- Highest product quality and reliability under new loading condition and arrive at a conclusion
- Customer satisfaction whether existing front axle can do the job or total redesign
- Reduction of development time and costs. of the component is required.
The urgent issues for industrial companies today are Leon et al. (2000) used experimental and numerical
how to reduce the time and cost required for developing a methods, for the stress analysis of a frontal truck axle beam.
new product (Beckert, 1996; Kojima, 2002). Accordingly, The results obtained by finite element method were verified
they have tried to use the computer’s huge memory capacity, experimentally using photo stress. Mahanty et al. (2001)
fast processing speed and user-friendly interactive graphics performed an experimental and numerical analysis of a
capability to automate and tie together other-wise tractor’s front axle. Based on finite element analysis results
cumbersome and separate engineering or production tasks, redesign was carried out for the front axle for weight
thus reducing the time and cost of product development and optimization and easy manufacturability. Five different
production. Computer-aided design (CAD), computer-aided models were proposed based on ease of manufacture and
manufacturing (CAM), computer-aided engineering (CAE) weight reduction. The results obtained by finite element
are the technologies used for this purpose during the product method were analyzed by thirteen different certification test
cycle (Lee, 1999). load conditions. Maly and Bazzaz (2003) used experimental
ICMCO has manufactured JD 955 combines since and numerical methods, for design change from casting to
many years in Iran. ICMCO modified the existing product welding for an axle casing.
in order to improve its product quality and efficiency, while
reducing development time. During product modification MATERIALS AND METHODS
the variations occurred in existing combine for example:
increasing grain tank capacity, using longer discharge tube, Material data. The front axle of JD 955 combine was made
increasing engine power, adding driver chamber, using from St 37-2 with following material properties:
internal volume of front axle as compressed air tank etc E = 200000 MPa Young’s modulus
(Ayyazi, 2004). Therefore the loads applied on the front ν = 0.3 Poisson’s ratio
axle of combine were increased due to the variations ρ = 8000 kg/m3 Density
occurred in the modified combine. Front axle of combine is
one of the major and very important component and needs σy = 235 MPa Yield stress
JAFARI et al. / J. Agri. Soc. Sci., Vol. 2, No. 3, 2006
σu = 340 MPa Limit stress. Fig. 1. Meshed model of front axle of JD 955 combine
Loads on front axle beam. All vehicles are subjected to
both static and dynamic loads. In this study, only static loads
that applied on the front axle of combine is considered.
Front axle of combine is considered as a support for front
wheels, hydraulic cylinders of combine’s head, gear-box,
bodywork or super-structure etc.
Static loads that applied on front axle are as follows:
vertical right and left bodywork loads, vertical loads on the
gear-box supports, head lifting loads from hydraulic
cylinders. These forces were determined by experimental
and theoretical methods.
Analysis. The commercial finite element package ANSYS
version 9.0 was used for the solution of the problem (2005).
The geometric model for the front axle was created based on 1
Von-Mises stress ( σ ′ ) = ⎡ (σ1 −σ2 ) + (σ2 −σ3 ) + (σ1 −σ3 ) ⎤
2 2 2 2
the drawings provided. Several simplifications of the model
⎢ ⎥
structure have been made with the purpose of reducing the ⎣ 2 ⎦
analysis time and size model (In order to increase accuracy
of the analyses). These simplifications are as follows: Where σ 1 , σ2 , σ3 = Principal stresses associated with the
omitting the side bodywork bases, omitting holes in the side three principal directions.
connection plates and omitting gear-box supports. The front According to distortion-energy theory, allowable stress
axle is modeled with two dimensional elements, SOLID 82 in order to avoid fracture is equal to yield stress strength.
and hexahedral three dimensional elements, SOLID 95. At Factor of safety can be calculated by dividing yield stress to
first the cross-section areas of the lower box, upper box, maximum Von-Mises stress.
hydraulic cylinders supports and connection plates were
meshed using the SOLID 82 elements and then these cross RESULTS AND DISCUSSION
section areas were extruded using the SOLID 95 elements.
The individual components have been coupled together so The results of the analysis of the model that was
that there is no free motion between components. The upper meshed with elements with average size of 10 mm are given
box has been coupled to the lower box and the hydraulic in Fig. 2. As seen from the figure the maximum Von-Mises
cylinder supports have been coupled with the lower box and stress appear on the upper box and near to the left
the connection plates have been coupled with the lower and connection plate as shown by the arrow in Fig. 2.
upper box assemblies. From the value of maximum induced stress and
The next step was the definition of the boundary allowable stress a factor of safety value is calculated 1.3 and
conditions. All degrees of freedom are constrained at the found to be less than required value. Calculated value of
connection plates of the model. The next step was the factor of safety is very low and obviously this value
definition of the loads that has to be previously described decreases under cyclic loading conditions of field operation.
and defined. The present study clearly indicates that the front axle of JD
The static analysis of front axle was carried out after 955 combine isn’t strong enough to be installed on the
several sensitivity analyses; elements with average size of modified combine. There is a need to optimize the existing
10 mm were used. The size of the finite model is design of the front axle of JD 955 combine in order to install
approximately 19000 elements and 123000 nodes. Meshed on modified combine. Suggested modifications to increase
model of front axle of JD 955 combine is shown in Fig. 1. strength and reliability are:
After obtaining the solution the results of analysis can be 1. Increase the thickness of upper box and lower box,
reviewed using post processing to determine maximum 2. Use horizontal bodywork supports instead of vertical
induced stress and its location. bodywork supports,
Calculating factor of safety. In designing parts to resist 3. Reduce welding in order to reduce stress relief and
failure, it is assured that the internal stresses do not exceed cost.
the strength of the material. If the material to be used is
ductile, then it is the yield strength that designer is usually CONCLUSION
interested in, because a permanent deformation would
constitute failure. The distortion-energy theory is also called
In this study, the finite element analysis of front axle
the Von-Mises theory, which is the most suitable theory to
of JD 955 combine under static loading conditions resulted
be used in ductile materials (Shigley & Mischke, 1989).
from the applied modifications was carried out. Calculated
Von-Mises stress is calculated by using the formula:
value of factor of safety is very low and obviously this value
134
STRESS ANALYSIS OF FRONT AXLE OF COMBINE HARVESTER UNDER STATIC LOADING / J. Agri. Soc. Sci., Vol. 2, No. 3, 2006
Fig. 2. Von-Mises stress distribution on front axle acknowledged. The authors would like to thank Mr. A.
Setayesh, Head, Research and Development, Iran Combine
Manufacturing Company, for useful discussions. The
authors are indebted to Dr. M. Behrouzilar for his valuable
guidance in carrying out this study.
REFERENCES
ANSYS IP Inc., 2005. ANSYS User's Manual. Ver.9.0. ANSYS IP Inc
Ayyazi, M., 2004. Designing and Fabricating of Platform for JD1165
Combine. Master of Science Thesis, Tehran University
Beckert, B.A., 1996. Venturing into Virtual Product Development,
Computer-Aided Engineering, Pp: 45–50
Kojima, Y., 2002. Mechanical CAE in Automotive Design. R & D Review
of Toyota CRDL, 35: 1–10
Lee, K., 1999. Principles of CAD/CAM/CAE Ststems. Addison-Wesley, Inc
Leon, N., P.O. Martinez and P. Adaya, 2000. Reducing the Weight of a
Frontal Axle Beam Using Experimental Test Procedures to Fine
Tune FEA, 2nd Worldwide MSC Automotive Conference, Dearborn,
Michigan
decreases under cyclic loading conditions of field operation. Mahanty, K.D., V. Manohar, B.S. Khomane and S. Nayak, 2001. Analysis
The present study clearly indicates that the front axle of JD and Weight Reduction of a Tractor’s Front Axle. Tata Consultancy
955 combine isn’t strong enough to be installed on the Services, India, Swarup Udgata, International Auto Limited, India
modified combine. There is a need to optimize the existing Shigley, J.E. and C.R. Mischke, 1989. Mechanical Engineering Design, 5th
Edition. McGraw-Hill Book Company
design of the front axle of JD 955 combine in order to install Maly, J. and E. Bazzaz, 2003. Design Change from Casting to Welding for
on modified combine. an Axle Casing. http://WWW.aveng.com/Paper_ MSC_03.pdf
Acknowledgments. The financial support provided by the
Research Department of University of Tehran of I.R. IRAN
(Received 15 May 2006; Accepted 15 June 2006)
under research award number 7109015/6/01 is gratefully
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